ProtoCore v0.0.1
Deterministic, zero-heap network stack for embedded targets
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Documentation

A multi-protocol network server for ESP32 with a fully deterministic memory footprint, RFC 7230 compliant request parsing, and an OSI-layered architecture. It serves HTTP/1.1 and HTTP/2 (with HTTP/3 over QUIC, host-tested), WebSocket, and Server-Sent Events, with optional HTTPS/TLS, SSH, Telnet, SNMP, CoAP, Modbus TCP, MQTT, and OPC UA.

Installation

PlatformIO:

lib_deps = https://github.com/dstroy0/ProtoCore.git

Arduino IDE: Download the repository as a ZIP and use Sketch → Include Library → Add .ZIP Library.

Quick Start

#include <WiFi.h>
#include "protocore.h"
#include "network_drivers/physical/physical.h"
PC server;
void handle_status(uint8_t slot_id, HttpReq *req)
{
server.send(slot_id, 200, "application/json", "{\"ok\":true}");
}
void setup()
{
init_wifi_physical("SSID", "PASSWORD");
while (!wifi_ready()) delay(250);
server.on("/status", HTTP_GET, handle_status);
server.set_cors("*");
server.begin(80);
}
void loop()
{
server.handle();
}
PC
Single-port HTTP server with deterministic, zero-allocation execution.
Definition protocore.h:348
PC::send
void send(uint8_t slot_id, int code, const char *content_type, const char *payload)
Send an HTTP response with a body and close the connection.
Definition protocore.cpp:1916
PC::begin
int32_t begin(const WebServerConfig *cfg=nullptr)
Initialize all connection slots and open all registered listeners.
Definition protocore.cpp:601
PC::on
void on(const char *path, HttpMethod method, Handler callback)
Register a route handler.
Definition protocore.cpp:898
PC::handle
void handle()
Drive the server - call every Arduino loop() iteration.
Definition protocore.cpp:1203
PC::set_cors
void set_cors(const char *origin)
Enable CORS by pre-building the Access-Control headers.
Definition protocore.cpp:1016
init_wifi_physical
bool init_wifi_physical(const char *, const char *)
Connect to a WiFi access point.
Definition physical.cpp:41
wifi_ready
bool wifi_ready()
True if the WiFi station link is up (associated + an IP is assigned).
Definition physical.cpp:45
physical.h
Layer 1 (Physical) - link bring-up and live egress-interface reporting.
protocore.h
Layer 7 (Application) - public HTTP routing API.
HttpMethod::HTTP_GET
@ HTTP_GET
Safe, idempotent read.
HttpReq
Fully-parsed HTTP/1.1 request.
Definition http_parser.h:111

See examples/Foundation/Configuration/Configuration.ino for a full reference of every configurable flag and constant.

Features

A compile-time menu grouped by the OSI layer each feature lives at, alphabetized within each layer: each cell is an optional PC_ENABLE_* subsystem (core HTTP/1.1, routing, middleware, JSON, templating, and chunked responses are always on). Hover an entry for its summary; click through to FEATURES.md for the full description. The tables are generated from FEATURES.md by ci_tooling/generate/gen_feature_tables.py, so they never drift.

Foundation
Config IO Config Store Device ID DMA Peripheral Ingest Exception Decoder
Failsafe Watchdog GPIO Map Guardrails Hardware Health Preempting Work Queue
PSRAM Pool RTC Sleep Scheduler Southbound Time Source
VFS Wear Leveling
Physical & Data Link (L1-L2)
ADS1115 BLE GATT Bus Capture CC1101 DShot
EnOcean ESP-NOW Ethernet FDC2214 INA219
Interface Forwarding LD2410 LDC1614 LoRa MPR121
nRF24 PCA9685 PN532 Radio Gateway Radio Power
Radio Sniffer Raw L2 SHT3x Sigfox Thread
VL53L0X Wi-Fi Capture Wi-Fi Sniffer Wi-SUN Z-Wave
Zigbee
Network (L3)
Dns Resolver Happy Eyeballs IPv6 Link Manager Network Adaptation
Proxy Protocol
Transport (L4)
Accept Throttle IP Allowlist Keep-Alive MTLS Per IP Throttle
Socket Pool TLS TLS Policy TLS Resumption
Session (L5)
SSH SSH Compression SSH SCP SSH SFTP Telnet
Presentation (L6)
Auth Auth Lockout CBOR CloudEvents HTTP Delivery
HTTP/1.1 Parser HTTP/2 HTTP/3 JSON JWT
MessagePack Multipart Protobuf SenML SSE
Web Terminal WebSocket WS Deflate
Web & HTTP
Chunked Responses CORS Dashboard Edge Cache Edge Cache Mesh
ETag File Serving HTTP Cache Middleware Range
Routing SPA Router Templating Themes Upload
WebDAV
Auth, Identity & Security
Audit Log CSRF OAuth2 OIDC TOTP
IoT, Messaging & APIs
AMQP CoAP CoAP Block CoAP Observe DDS-RTPS
GraphQL gRPC-Web LwM2M MQTT MQTT SN
MQTT TLS NATS Sparkplug Stomp WAMP
XMPP
Industrial & Fieldbus
ADS (Beckhoff) BACnet CANopen CC-Link CiA 402
CIP Control COTP DeviceNet DF1
DirectNET DMX512 EtherNet/IP FINS HART
Host Link INTERBUS IO-Link LonWorks MELSEC
Modbus Modbus Master Modbus Plus Modbus RTU POWERLINK
PROFIBUS PROFINET S7comm SDI-12 SERCOS III
SNP
SCADA, Energy & Monitoring
C37.118 DNP3 GOOSE ICCP IEC 60870
M-Bus MMS OpenADR SEP2 SunSpec
Machine Tools & OT
DNC (CNC drip-feed) MTConnect OPC-UA OPC-UA Client umati (OPC UA for Machine Tools)
Transportation & ITS
ATC J1939 J2735 NEMA TS2 NMEA 0183
NMEA 2000 NTCIP OCIT UTMC WAVE
Clients & Gateways
FTP client HTTP Client HTTP Client TLS Relay (TCP forward / DNAT) SMB
SMTP Webhook WS Client WS Client TLS
Storage & Database
DBM Key-Value Store Document Store Redis SQLite Write-Ahead Log
Time & Discovery
Adaptive mDNS DNS Server MDNS NTP NTP Server
NTS PTP
Observability & Telemetry
Diag Flow Export Log-Buffer Metrics Observability
Partition Monitor SNMP SNMP Trap SNMP V3 Stats
StatsD Syslog Telemetry UDP Telemetry
Firmware & System
OTA OTA Rollback Provisioning
Application (L7) - Other
AD9238 DiffServ QoS Marking DTLS 1.3 Edge Cache Origin TLS EUROMAP 77 (OPC UA for injection moulding)
FANUC FOCAS FANUC Stream Motion (J519) Forwarded Trust FTP client session GPIB
Haas MDC HiSLIP HMMD Hot-Swap Storage IKEv2
Interface Bridge Logging macros LSV/2 NTRIP Caster OPC UA Robotics (MotionDevice)
PackML Post-Quantum Hybrid KEX Power Governor RCWL-0516 Safety SCL (IEC 61784-3)
SCPI SEN0192 SIMATIC Serial SMTP TLS SSH Keyboard-Interactive
SSH Reverse Tunnel Streaming Request Body TLS Raw Public Keys Trace Capture UBX (u-blox binary)
VXI-11 Wi-Fi Roaming

New to this? Start here

If networking is new to you, the learn series is a from-scratch on-ramp that assumes no prior knowledge: the OSI model, TCP/IP, and a primer on every language in the project - each tied back to the code below. Every protocol the library implements is mapped to its authoritative spec in STANDARDS.md.

Architecture

Each OSI layer lives in its own subdirectory under src/network_drivers/:

View Directory and OSI Layer Layout

L7 src/protocore.h/cpp Route table, dispatch, send()
L6 src/network_drivers/presentation/
presentation.h/cpp Drains ring buffer → parser
http_parser.h/cpp RFC 7230 byte-stream state machine
sha1.h/cpp base64.h/cpp mbedTLS hardware-accelerated helpers
websocket.h/cpp sse.h/cpp WS frame parser; SSE connection pool
multipart.h/cpp Multipart form-data parser
L5 src/network_drivers/session/
session.h/cpp FreeRTOS event queue drain
L4 src/network_drivers/transport/
tcp.h/cpp lwIP callbacks, ring buffers, timeouts
listener.h/cpp Per-port TCP listener, per-listener queue
L3 src/network_drivers/network/
network.h/cpp lwIP stub
L2 src/network_drivers/datalink/
datalink.h/cpp Espressif WiFi driver stub
L1 src/network_drivers/physical/
physical.h/cpp WiFi.begin() wrapper
src/network_drivers/tls/ mbedTLS over a fixed static pool (HTTPS / wss)
src/network_drivers/application/ Generated web assets (dashboard, terminal)
src/network_drivers/presentation/ssh/ Zero-heap SSH-2.0 server
src/services/ Optional L7 subsystems, one folder each:
opcua/ + opcua_client/, modbus/, mqtt/, coap/, snmp/, dns_resolver/, oidc/,
oauth2/, totp/, audit_log/, vfs/, graphql/, espnow/, ... (see FEATURES.md)

The conceptual layer map above is a summary; the complete file layout is generated below from src/ by ci_tooling/generate/gen_readme_sections.py (single-.h/.cpp service folders are collapsed to their name; generated web-asset blobs are counted, not listed).

Full source tree (every library file)

src/
├── board_drivers/
│ ├── board_profiles/
│ │ ├── esp/
│ │ │ ├── 16mbflash.h
│ │ │ ├── 16mbpsram.h
│ │ │ ├── 2mbflash.h
│ │ │ ├── 2mbpsram.h
│ │ │ ├── 32mbflash.h
│ │ │ ├── 32mbpsram.h
│ │ │ ├── 4mbflash.h
│ │ │ ├── 4mbpsram.h
│ │ │ ├── 8mbflash.h
│ │ │ ├── 8mbpsram.h
│ │ │ ├── c2_defaults.h
│ │ │ ├── c3_defaults.h
│ │ │ ├── c5_defaults.h
│ │ │ ├── c61_defaults.h
│ │ │ ├── c6_defaults.h
│ │ │ ├── h21_defaults.h
│ │ │ ├── h2_defaults.h
│ │ │ ├── h4_defaults.h
│ │ │ ├── p4_defaults.h
│ │ │ ├── s2_defaults.h
│ │ │ ├── s31_defaults.h
│ │ │ └── s3_defaults.h
│ │ ├── board_profile.h
│ │ ├── classic_defaults.h
│ │ ├── derived_sizing.h
│ │ └── pc_platform.h
│ ├── hal/
│ │ ├── esp/
│ │ │ ├── C2_AND_S.md
│ │ │ ├── C3_CRYPTO_REG_SYMBOLS.md
│ │ │ ├── C6_CRYPTO_REG_SYMBOLS.md
│ │ │ ├── CLASSIC_CRYPTO_REG_SYMBOLS.md
│ │ │ ├── DMA_GDMA.md
│ │ │ ├── E_CRYPTO_REG_SYMBOLS.md
│ │ │ ├── esp_aes128gcm.cpp
│ │ │ ├── esp_aesgcm.cpp
│ │ │ ├── esp_bignum.cpp
│ │ │ ├── esp_crypto_hal.cpp
│ │ │ ├── esp_crypto_hal.h
│ │ │ ├── esp_platform.cpp
│ │ │ ├── H2_CRYPTO_REG_SYMBOLS.md
│ │ │ ├── P4_CRYPTO_REG_SYMBOLS.md
│ │ │ ├── P4_MIPI_DSI_CSI.md
│ │ │ ├── P4_MIPI_HELPERS.md
│ │ │ ├── S2.md
│ │ │ └── S3_CRYPTO_REG_SYMBOLS.md
│ │ └── portable/
│ │ ├── portable_aes128gcm.cpp
│ │ ├── portable_aesgcm.cpp
│ │ ├── portable_bignum.cpp
│ │ └── portable_platform.cpp
│ └── physical/
│ └── esp/
│ └── physical_esp.cpp
├── crypto/
│ ├── aead/
│ │ ├── aes128gcm.h
│ │ ├── aesccm.cpp
│ │ ├── aesccm.h
│ │ ├── aesgcm.cpp
│ │ ├── aesgcm.h
│ │ ├── chachapoly.cpp
│ │ └── chachapoly.h
│ ├── asymmetric/
│ │ ├── bignum.cpp
│ │ ├── bignum.h
│ │ ├── curve25519.cpp
│ │ ├── curve25519.h
│ │ ├── ecdsa.cpp
│ │ ├── ecdsa.h
│ │ ├── ed25519.cpp
│ │ ├── ed25519.h
│ │ ├── ed25519_comb_table.h
│ │ ├── fe25519.h
│ │ ├── rsa.cpp
│ │ └── rsa.h
│ ├── cipher/
│ │ ├── aes256ctr.cpp
│ │ ├── aes256ctr.h
│ │ ├── aes_block.h
│ │ ├── aes_sbox.h
│ │ ├── chacha20.cpp
│ │ └── chacha20.h
│ ├── hash/
│ │ ├── md.cpp
│ │ ├── md.h
│ │ ├── sha1.cpp
│ │ ├── sha1.h
│ │ ├── sha256.cpp
│ │ ├── sha256.h
│ │ ├── sha3.cpp
│ │ ├── sha3.h
│ │ ├── sha512.cpp
│ │ └── sha512.h
│ ├── kdf/
│ │ ├── hkdf.cpp
│ │ ├── hkdf.h
│ │ ├── kdf.cpp
│ │ ├── kdf.h
│ │ ├── tls13_kdf.cpp
│ │ └── tls13_kdf.h
│ ├── mac/
│ │ ├── aes_cmac.cpp
│ │ ├── aes_cmac.h
│ │ ├── ghash.h
│ │ ├── hmac_sha256.cpp
│ │ ├── hmac_sha256.h
│ │ ├── hmac_sha512.cpp
│ │ ├── hmac_sha512.h
│ │ ├── poly1305.cpp
│ │ └── poly1305.h
│ ├── pqc/
│ │ ├── mlkem.cpp
│ │ ├── mlkem.h
│ │ ├── sntrup761.cpp
│ │ └── sntrup761.h
│ ├── crypto_opt.h
│ └── crypto_scratch.h
├── network_drivers/
│ ├── application/
│ │ ├── binary_asset_blobs.cpp
│ │ ├── binary_asset_blobs.h
│ │ ├── web_assets.cpp
│ │ └── web_assets.h
│ ├── datalink/ (datalink.h, datalink.cpp)
│ ├── network/
│ │ ├── ip.cpp
│ │ ├── ip.h
│ │ ├── network.cpp
│ │ └── network.h
│ ├── physical/ (physical.h, physical.cpp)
│ ├── presentation/
│ │ ├── codec/
│ │ │ ├── base64/ (base64.h, base64.cpp)
│ │ │ ├── cbor/ (cbor.h, cbor.cpp)
│ │ │ ├── deflate/ (deflate.h, deflate.cpp)
│ │ │ ├── hpack_prim/ (hpack_prim.h, hpack_prim.cpp)
│ │ │ ├── inflate/ (inflate.h, inflate.cpp)
│ │ │ ├── json/ (json.h, json.cpp)
│ │ │ ├── msgpack/ (msgpack.h, msgpack.cpp)
│ │ │ └── multipart/ (multipart.h, multipart.cpp)
│ │ ├── http/
│ │ │ ├── http2/
│ │ │ │ ├── h2_conn.cpp
│ │ │ │ ├── h2_conn.h
│ │ │ │ ├── h2_frame.cpp
│ │ │ │ ├── h2_frame.h
│ │ │ │ ├── h2_server.cpp
│ │ │ │ ├── h2_server.h
│ │ │ │ ├── hpack.cpp
│ │ │ │ └── hpack.h
│ │ │ ├── http3/
│ │ │ │ ├── h3_conn.cpp
│ │ │ │ ├── h3_conn.h
│ │ │ │ ├── h3_frame.cpp
│ │ │ │ ├── h3_frame.h
│ │ │ │ ├── qpack.cpp
│ │ │ │ ├── qpack.h
│ │ │ │ ├── quic_conn.cpp
│ │ │ │ ├── quic_conn.h
│ │ │ │ ├── quic_crypto.cpp
│ │ │ │ ├── quic_crypto.h
│ │ │ │ ├── quic_frame.cpp
│ │ │ │ ├── quic_frame.h
│ │ │ │ ├── quic_packet.cpp
│ │ │ │ ├── quic_packet.h
│ │ │ │ ├── quic_server.cpp
│ │ │ │ ├── quic_server.h
│ │ │ │ ├── quic_tls.cpp
│ │ │ │ ├── quic_tls.h
│ │ │ │ ├── quic_tp.cpp
│ │ │ │ ├── quic_tp.h
│ │ │ │ ├── quic_varint.cpp
│ │ │ │ ├── quic_varint.h
│ │ │ │ ├── tls13_msg.cpp
│ │ │ │ └── tls13_msg.h
│ │ │ ├── http_parser/ (http_parser.h, http_parser.cpp)
│ │ │ ├── sse/ (sse.h, sse.cpp)
│ │ │ └── websocket/ (websocket.h, websocket.cpp)
│ │ ├── security/
│ │ │ └── dtls/
│ │ │ ├── dtls_conn.cpp
│ │ │ ├── dtls_conn.h
│ │ │ ├── dtls_handshake.cpp
│ │ │ ├── dtls_handshake.h
│ │ │ ├── dtls_record.cpp
│ │ │ └── dtls_record.h
│ │ ├── ssh/
│ │ │ ├── auth/ (ssh_auth.h, ssh_auth.cpp)
│ │ │ ├── connection/
│ │ │ │ ├── ssh_channel.cpp
│ │ │ │ ├── ssh_channel.h
│ │ │ │ ├── ssh_client.cpp
│ │ │ │ ├── ssh_client.h
│ │ │ │ ├── ssh_conn.cpp
│ │ │ │ ├── ssh_conn.h
│ │ │ │ ├── ssh_forward.cpp
│ │ │ │ ├── ssh_forward.h
│ │ │ │ ├── ssh_server.cpp
│ │ │ │ └── ssh_server.h
│ │ │ ├── crypto/
│ │ │ │ ├── ssh_kexhash.h
│ │ │ │ ├── ssh_rsa.cpp
│ │ │ │ └── ssh_rsa.h
│ │ │ └── transport/
│ │ │ ├── ssh_comp.cpp
│ │ │ ├── ssh_comp.h
│ │ │ ├── ssh_dh.cpp
│ │ │ ├── ssh_dh.h
│ │ │ ├── ssh_inflate.cpp
│ │ │ ├── ssh_inflate.h
│ │ │ ├── ssh_keymat.cpp
│ │ │ ├── ssh_keymat.h
│ │ │ ├── ssh_packet.cpp
│ │ │ ├── ssh_packet.h
│ │ │ ├── ssh_transport.cpp
│ │ │ ├── ssh_transport.h
│ │ │ ├── ssh_zlib.cpp
│ │ │ └── ssh_zlib.h
│ │ ├── telnet/ (telnet.h, telnet.cpp)
│ │ ├── presentation.cpp
│ │ └── presentation.h
│ ├── session/
│ │ ├── proto_builtins.cpp
│ │ ├── proto_handler.h
│ │ ├── session.cpp
│ │ ├── session.h
│ │ ├── worker.cpp
│ │ └── worker.h
│ ├── tls/ (tls.h, tls.cpp)
│ └── transport/
│ ├── client.cpp
│ ├── client.h
│ ├── diffserv.cpp
│ ├── diffserv.h
│ ├── listener.cpp
│ ├── listener.h
│ ├── tcp.cpp
│ ├── tcp.h
│ ├── udp.cpp
│ └── udp.h
├── server/
│ ├── mmgr/
│ │ ├── arena.cpp
│ │ ├── arena.h
│ │ ├── scratch.cpp
│ │ ├── scratch.h
│ │ ├── secure.cpp
│ │ └── secure.h
│ ├── auth.cpp
│ ├── file_serving.cpp
│ ├── fs_path.h
│ ├── http_range.cpp
│ ├── http_range.h
│ ├── middleware.cpp
│ ├── protocore_internal.h
│ ├── regex.cpp
│ ├── response.cpp
│ ├── ssh_scp.cpp
│ ├── ssh_scp.h
│ ├── ssh_sftp.cpp
│ ├── ssh_sftp.h
│ ├── webdav.cpp
│ └── websocket_sse.cpp
├── services/
│ ├── energy/
│ │ ├── c37118/ (c37118.h, c37118.cpp)
│ │ ├── dnp3/ (dnp3.h, dnp3.cpp)
│ │ ├── goose/ (goose.h, goose.cpp)
│ │ ├── iccp/ (iccp.h, iccp.cpp)
│ │ ├── iec60870/ (iec60870.h, iec60870.cpp)
│ │ ├── mms/ (mms.h, mms.cpp)
│ │ ├── openadr/ (openadr.h, openadr.cpp)
│ │ ├── sep2/ (sep2.h, sep2.cpp)
│ │ └── sunspec/ (sunspec.h, sunspec.cpp)
│ ├── fieldbus/
│ │ ├── ads/ (ads.h, ads.cpp)
│ │ ├── bacnet/ (bacnet.h, bacnet.cpp)
│ │ ├── canopen/ (canopen.h, canopen.cpp)
│ │ ├── cclink/ (cclink.h, cclink.cpp)
│ │ ├── cia402/ (cia402.h, cia402.cpp)
│ │ ├── cip/ (cip.h, cip.cpp)
│ │ ├── cotp/ (cotp.h, cotp.cpp)
│ │ ├── devicenet/ (devicenet.h, devicenet.cpp)
│ │ ├── df1/ (df1.h, df1.cpp)
│ │ ├── directnet/ (directnet.h, directnet.cpp)
│ │ ├── enip/ (enip.h, enip.cpp)
│ │ ├── fins/ (fins.h, fins.cpp)
│ │ ├── hart/ (hart.h, hart.cpp)
│ │ ├── hostlink/ (hostlink.h, hostlink.cpp)
│ │ ├── interbus/ (interbus.h, interbus.cpp)
│ │ ├── iolink/ (iolink.h, iolink.cpp)
│ │ ├── j1939/ (j1939.h, j1939.cpp)
│ │ ├── lonworks/ (lonworks.h, lonworks.cpp)
│ │ ├── mbplus/ (mbplus.h, mbplus.cpp)
│ │ ├── mbus/ (mbus.h, mbus.cpp)
│ │ ├── melsec/ (melsec.h, melsec.cpp)
│ │ ├── modbus/
│ │ │ ├── modbus.cpp
│ │ │ ├── modbus.h
│ │ │ ├── modbus_master.cpp
│ │ │ └── modbus_master.h
│ │ ├── opcua/ (opcua.h, opcua.cpp)
│ │ ├── opcua_client/ (opcua_client.h, opcua_client.cpp)
│ │ ├── powerlink/ (powerlink.h, powerlink.cpp)
│ │ ├── profibus/ (profibus.h, profibus.cpp)
│ │ ├── profinet/ (profinet.h, profinet.cpp)
│ │ ├── rawl2/ (rawl2.h, rawl2.cpp)
│ │ ├── s7comm/ (s7comm.h, s7comm.cpp)
│ │ ├── sercos/ (sercos.h, sercos.cpp)
│ │ ├── simatic/ (simatic.h, simatic.cpp)
│ │ └── snp/ (snp.h, snp.cpp)
│ ├── file_transfer/
│ │ ├── ftp/
│ │ │ ├── ftp.cpp
│ │ │ ├── ftp.h
│ │ │ ├── ftp_session.cpp
│ │ │ └── ftp_session.h
│ │ ├── http_delivery/
│ │ │ ├── http_delivery.cpp
│ │ │ ├── http_delivery.h
│ │ │ └── http_delivery_routes.cpp
│ │ ├── scp/ (scp.h, scp.cpp)
│ │ ├── sftp/ (sftp.h, sftp.cpp)
│ │ ├── smb/
│ │ │ ├── ntlm.cpp
│ │ │ ├── ntlm.h
│ │ │ ├── ntlmssp.cpp
│ │ │ ├── ntlmssp.h
│ │ │ ├── smb2.cpp
│ │ │ ├── smb2.h
│ │ │ ├── smb_client.cpp
│ │ │ ├── smb_client.h
│ │ │ ├── spnego.cpp
│ │ │ └── spnego.h
│ │ ├── upload_service/ (upload_service.h, upload_service.cpp)
│ │ └── webdav/ (webdav.h, webdav.cpp)
│ ├── instrumentation/
│ │ ├── gpib/ (gpib.h, gpib.cpp)
│ │ ├── hislip/ (hislip.h, hislip.cpp)
│ │ ├── scpi/ (scpi.h, scpi.cpp)
│ │ └── vxi11/ (vxi11.h, vxi11.cpp)
│ ├── iot/
│ │ ├── amqp/ (amqp.h, amqp.cpp)
│ │ ├── cloudevents/ (cloudevents.h, cloudevents.cpp)
│ │ ├── coap/
│ │ │ ├── coap.cpp
│ │ │ ├── coap.h
│ │ │ ├── coaps.cpp
│ │ │ ├── coaps.h
│ │ │ ├── coaps_server.cpp
│ │ │ └── coaps_server.h
│ │ ├── dds/ (dds.h, dds.cpp)
│ │ ├── graphql/ (graphql.h, graphql.cpp)
│ │ ├── grpcweb/ (grpcweb.h, grpcweb.cpp)
│ │ ├── lwm2m/ (lwm2m_tlv.h, lwm2m_tlv.cpp)
│ │ ├── mqtt/
│ │ │ ├── mqtt.cpp
│ │ │ ├── mqtt.h
│ │ │ ├── mqtt_sn.cpp
│ │ │ └── mqtt_sn.h
│ │ ├── nats/ (nats.h, nats.cpp)
│ │ ├── protobuf/ (protobuf.h, protobuf.cpp)
│ │ ├── redis_resp/ (redis_resp.h, redis_resp.cpp)
│ │ ├── senml/ (senml.h, senml.cpp)
│ │ ├── sparkplug/ (sparkplug.h, sparkplug.cpp)
│ │ ├── statsd/ (statsd.h, statsd.cpp)
│ │ ├── stomp/ (stomp.h, stomp.cpp)
│ │ ├── telemetry/ (telemetry.h, telemetry.cpp)
│ │ ├── udp_telemetry/ (udp_telemetry.h, udp_telemetry.cpp)
│ │ ├── wamp/ (wamp.h, wamp.cpp)
│ │ └── xmpp/ (xmpp.h, xmpp.cpp)
│ ├── machine_tool/
│ │ ├── atc/ (atc.h, atc.cpp)
│ │ ├── dnc/
│ │ │ ├── dnc.cpp
│ │ │ ├── dnc.h
│ │ │ ├── dnc_stream.cpp
│ │ │ └── dnc_stream.h
│ │ ├── euromap77/ (euromap77.h, euromap77.cpp)
│ │ ├── fanuc_j519/ (fanuc_j519.h, fanuc_j519.cpp)
│ │ ├── focas/ (focas.h, focas.cpp)
│ │ ├── haas_mdc/ (haas_mdc.h, haas_mdc.cpp)
│ │ ├── lsv2/ (lsv2.h, lsv2.cpp)
│ │ ├── mtconnect/ (mtconnect.h, mtconnect.cpp)
│ │ ├── packml/ (packml.h, packml.cpp)
│ │ ├── robotics/ (robotics.h, robotics.cpp)
│ │ ├── safety_scl/ (safety_scl.h, safety_scl.cpp)
│ │ └── umati/ (umati.h, umati.cpp)
│ ├── net/
│ │ ├── dns_resolver/ (dns_resolver.h, dns_resolver.cpp)
│ │ ├── dns_server/ (dns_server.h, dns_server.cpp)
│ │ ├── flow_export/ (flow_export.h, flow_export.cpp)
│ │ ├── forward/ (forward.h, forward.cpp)
│ │ ├── gateway/ (gateway.h, gateway.cpp)
│ │ ├── happy_eyeballs/ (happy_eyeballs.h, happy_eyeballs.cpp)
│ │ ├── http_client/ (http_client.h, http_client.cpp)
│ │ ├── iface_bridge/
│ │ │ ├── iface_bridge.cpp
│ │ │ ├── iface_bridge.h
│ │ │ ├── iface_bridge_hw.cpp
│ │ │ └── iface_bridge_hw.h
│ │ ├── mdns_adaptive/ (mdns_adaptive.h, mdns_adaptive.cpp)
│ │ ├── mdns_service/ (mdns_service.h, mdns_service.cpp)
│ │ ├── netadapt/ (netadapt.h, netadapt.cpp)
│ │ ├── proxy_protocol/ (proxy_protocol.h, proxy_protocol.cpp)
│ │ ├── relay/
│ │ │ ├── relay.cpp
│ │ │ ├── relay.h
│ │ │ ├── relay_listener.cpp
│ │ │ └── relay_listener.h
│ │ ├── smtp/ (smtp.h, smtp.cpp)
│ │ ├── snmp/
│ │ │ ├── snmp_agent.cpp
│ │ │ ├── snmp_agent.h
│ │ │ ├── snmp_ber.cpp
│ │ │ ├── snmp_ber.h
│ │ │ ├── snmp_crypto.cpp
│ │ │ ├── snmp_crypto.h
│ │ │ ├── snmp_notify.cpp
│ │ │ ├── snmp_notify.h
│ │ │ ├── snmp_v3.cpp
│ │ │ └── snmp_v3.h
│ │ ├── sockpool/ (sockpool.h, sockpool.cpp)
│ │ ├── southbound/
│ │ │ ├── sb_modbus.cpp
│ │ │ ├── sb_modbus.h
│ │ │ ├── southbound.cpp
│ │ │ └── southbound.h
│ │ ├── syslog/ (syslog.h, syslog.cpp)
│ │ ├── webhook/ (webhook.h, webhook.cpp)
│ │ └── ws_client/ (ws_client.h, ws_client.cpp)
│ ├── peripherals/
│ │ ├── ad9238/ (ad9238.h, ad9238.cpp)
│ │ ├── ads1115/ (ads1115.h, ads1115.cpp)
│ │ ├── dmx/ (dmx.h, dmx.cpp)
│ │ ├── dshot/ (dshot.h, dshot.cpp)
│ │ ├── fdc2214/ (fdc2214.h, fdc2214.cpp)
│ │ ├── hmmd/ (hmmd.h, hmmd.cpp)
│ │ ├── ina219/ (ina219.h, ina219.cpp)
│ │ ├── ld2410/ (ld2410.h, ld2410.cpp)
│ │ ├── ldc1614/ (ldc1614.h, ldc1614.cpp)
│ │ ├── mpr121/ (mpr121.h, mpr121.cpp)
│ │ ├── pca9685/ (pca9685.h, pca9685.cpp)
│ │ ├── pn532/ (pn532.h, pn532.cpp)
│ │ ├── rcwl0516/ (rcwl0516.h, rcwl0516.cpp)
│ │ ├── rtc/ (rtc.h, rtc.cpp)
│ │ ├── sdi12/ (sdi12.h, sdi12.cpp)
│ │ ├── sen0192/ (sen0192.h, sen0192.cpp)
│ │ ├── sht3x/ (sht3x.h, sht3x.cpp)
│ │ ├── vl53l0x/ (vl53l0x.h, vl53l0x.cpp)
│ │ └── i2c.h
│ ├── radio/
│ │ ├── ble_gatt/ (ble_gatt.h, ble_gatt.cpp)
│ │ ├── cc1101/ (cc1101.h, cc1101.cpp)
│ │ ├── enocean/ (enocean.h, enocean.cpp)
│ │ ├── espnow/ (espnow.h, espnow.cpp)
│ │ ├── lora/ (lora.h, lora.cpp)
│ │ ├── nrf24/ (nrf24.h, nrf24.cpp)
│ │ ├── promisc/ (promisc.h, promisc.cpp)
│ │ ├── radio_sniff/ (radio_sniff.h, radio_sniff.cpp)
│ │ ├── sigfox/ (sigfox.h, sigfox.cpp)
│ │ ├── thread/ (thread.h, thread.cpp)
│ │ ├── wifi_sniffer/ (wifi_sniffer.h, wifi_sniffer.cpp)
│ │ ├── wisun/ (wisun.h, wisun.cpp)
│ │ ├── zigbee/ (zigbee.h, zigbee.cpp)
│ │ └── zwave/ (zwave.h, zwave.cpp)
│ ├── security/
│ │ ├── audit_log/ (audit_log.h, audit_log.cpp)
│ │ ├── auth_lockout/ (auth_lockout.h, auth_lockout.cpp)
│ │ ├── csrf/ (csrf.h, csrf.cpp)
│ │ ├── forwarded_trust/ (forwarded_trust.h, forwarded_trust.cpp)
│ │ ├── guardrails/ (guardrails.h, guardrails.cpp)
│ │ ├── ikev2/
│ │ │ ├── ikev2.cpp
│ │ │ ├── ikev2.h
│ │ │ ├── ikev2_natt.cpp
│ │ │ └── ikev2_natt.h
│ │ ├── jwt/ (jwt.h, jwt.cpp)
│ │ ├── oauth2/ (oauth2.h, oauth2.cpp)
│ │ ├── oidc/ (oidc.h, oidc.cpp)
│ │ ├── tls_policy/ (tls_policy.h, tls_policy.cpp)
│ │ └── totp/ (totp.h, totp.cpp)
│ ├── storage/
│ │ ├── config_io/ (config_io.h, config_io.cpp)
│ │ ├── config_store/ (config_store.h, config_store.cpp)
│ │ ├── dbm/ (dbm.h, dbm.cpp)
│ │ ├── docstore/ (docstore.h, docstore.cpp)
│ │ ├── hotswap/ (hotswap.h, hotswap.cpp)
│ │ ├── partition_monitor/
│ │ │ ├── partition_monitor.cpp
│ │ │ ├── partition_monitor.h
│ │ │ └── partition_monitor_routes.cpp
│ │ ├── psram_pool/ (psram_pool.h, psram_pool.cpp)
│ │ ├── sqlite/ (sqlite_format.h, sqlite_format.cpp)
│ │ ├── vfs/ (vfs.h, vfs.cpp)
│ │ ├── wal/
│ │ │ ├── wal.cpp
│ │ │ ├── wal.h
│ │ │ ├── wal_fs.h
│ │ │ ├── wal_store.cpp
│ │ │ └── wal_store.h
│ │ └── wearlevel/ (wearlevel.h, wearlevel.cpp)
│ ├── system/
│ │ ├── bus_capture/ (bus_capture.h, bus_capture.cpp)
│ │ ├── control/ (control.h, control.cpp)
│ │ ├── device_id/ (device_id.h, device_id.cpp)
│ │ ├── dma/ (dma.h, dma.cpp)
│ │ ├── esp/
│ │ │ ├── esp.cpp
│ │ │ ├── esp.h
│ │ │ ├── ipsec_db.cpp
│ │ │ └── ipsec_db.h
│ │ ├── exc_decoder/
│ │ │ ├── exc_coredump.cpp
│ │ │ ├── exc_decoder.cpp
│ │ │ └── exc_decoder.h
│ │ ├── failsafe/ (failsafe.h, failsafe.cpp)
│ │ ├── gpio_map/
│ │ │ ├── gpio_map.cpp
│ │ │ ├── gpio_map.h
│ │ │ └── gpio_map_routes.cpp
│ │ ├── hw_health/ (hw_health.h, hw_health.cpp)
│ │ ├── link_manager/ (link_manager.h, link_manager.cpp)
│ │ ├── logbuf/ (logbuf.h, logbuf.cpp)
│ │ ├── ota_rollback/ (ota_rollback.h, ota_rollback.cpp)
│ │ ├── ota_service/ (ota_service.h, ota_service.cpp)
│ │ ├── power_mgmt/ (power_mgmt.h, power_mgmt.cpp)
│ │ ├── preempt_queue/ (preempt_queue.h, preempt_queue.cpp)
│ │ ├── provisioning_service/ (provisioning_service.h, provisioning_service.cpp)
│ │ ├── radio_power/ (radio_power.h, radio_power.cpp)
│ │ ├── roaming/ (roaming.h, roaming.cpp)
│ │ ├── sleep_sched/ (sleep_sched.h, sleep_sched.cpp)
│ │ ├── trace_capture/ (trace_capture.h, trace_capture.cpp)
│ │ └── clock.h
│ ├── timing_position/
│ │ ├── gnss/
│ │ │ ├── gnss_survey.cpp
│ │ │ ├── gnss_survey.h
│ │ │ ├── ntrip_caster.cpp
│ │ │ ├── ntrip_caster.h
│ │ │ ├── ntrip_caster_listener.cpp
│ │ │ ├── ntrip_caster_listener.h
│ │ │ ├── rtcm3.cpp
│ │ │ └── rtcm3.h
│ │ ├── nmea0183/ (nmea0183.h, nmea0183.cpp)
│ │ ├── nmea2000/ (nmea2000.h, nmea2000.cpp)
│ │ ├── ntp_server/ (ntp_server.h, ntp_server.cpp)
│ │ ├── ntp_service/ (ntp_service.h, ntp_service.cpp)
│ │ ├── nts/ (nts.h, nts.cpp)
│ │ ├── ptp/ (ptp.h, ptp.cpp)
│ │ ├── time_source/ (time_source.h, time_source.cpp)
│ │ └── ubx/ (ubx.h, ubx.cpp)
│ ├── transportation/
│ │ ├── j2735/ (j2735.h, j2735.cpp)
│ │ ├── nema_ts2/ (nema_ts2.h, nema_ts2.cpp)
│ │ ├── ntcip/ (ntcip.h, ntcip.cpp)
│ │ ├── ocit/ (ocit.h, ocit.cpp)
│ │ ├── utmc/ (utmc.h, utmc.cpp)
│ │ └── wave/ (wave.h, wave.cpp)
│ └── web/
│ ├── dashboard/
│ │ ├── dashboard.cpp
│ │ ├── dashboard.h
│ │ └── dashboard_routes.cpp
│ ├── edge_cache/
│ │ ├── edge_cache.cpp
│ │ ├── edge_cache.h
│ │ ├── edge_cache_proxy.cpp
│ │ ├── edge_cache_proxy.h
│ │ ├── edge_cache_sd.cpp
│ │ ├── edge_cache_sd.h
│ │ ├── edge_fetch.cpp
│ │ ├── edge_fetch.h
│ │ ├── edge_mesh.cpp
│ │ └── edge_mesh.h
│ ├── httpcache/ (httpcache.h, httpcache.cpp)
│ ├── spa_router/ (spa_router.h, spa_router.cpp)
│ └── web_terminal/ (web_terminal.h, web_terminal.cpp)
├── shared_primitives/
│ ├── bitio.h
│ ├── bytes.h
│ ├── can.h
│ ├── crc.h
│ ├── endian.h
│ ├── frame.cpp
│ ├── frame.h
│ ├── hex.h
│ ├── http_date.h
│ ├── log.cpp
│ ├── log.h
│ ├── mime.h
│ ├── numparse.h
│ ├── pcap.h
│ ├── ring.h
│ ├── span.h
│ ├── speed_opt.h
│ ├── strbuf.h
│ ├── time_compat.h
│ └── utf8.h
├── protocore.cpp
├── protocore.h
└── protocore_config.h

Build Footprint

Measured flash + static RAM for each optional feature, built in isolation over the base server on esp32dev. Generated from docs/footprints.json (produced by the RPi build matrix) by ci_tooling/generate/gen_readme_sections.py.

Per-feature build footprint

Measured on esp32dev from each feature's isolated example (one feature enabled over the base server). Flash is the program image; RAM is static .data + .bss. Regenerated by the Feature Tables workflow from docs/footprints.json.

Feature Example Flash (bytes) Static RAM (bytes)
SIGFOX Drivers/SigfoxUplink 267,961 21,464
ENOCEAN+GATEWAY Drivers/EnOceanGateway 268,701 21,848
ZWAVE+GATEWAY Drivers/ZWaveGateway 268,905 21,848
ZIGBEE+GATEWAY Drivers/ZigbeeGateway 269,417 22,104
DMA+PREEMPT_QUEUE+DMA_SIMULATE Peripherals/DmaIngest 269,437 28,608
SEN0192 Drivers/Sen0192 269,805 21,488
core/SSHCryptoSelfTest L5-Session/SSHCryptoSelfTest 270,121 22,780
DMA+PREEMPT_QUEUE+GATEWAY+DMA_SIMULATE Drivers/RadioGateway 270,593 28,728
LD2410 Drivers/Ld2410 270,681 21,576
DMA+PREEMPT_QUEUE+FORWARD+DMA_SIMULATE Foundation/InterfaceForward 270,849 29,096
THREAD+GATEWAY Drivers/ThreadGateway 271,889 22,616
NMEA0183+UBX Drivers/UbloxGnss 273,765 22,432
PREEMPT_QUEUE Foundation/PreemptQueue 274,069 23,968
NRF24+GATEWAY Drivers/Nrf24Gateway 276,105 21,680
LORA+GATEWAY Drivers/LoRaGateway 276,329 21,688
PCA9685 Drivers/Pca9685 284,601 21,800
ADS1115 Drivers/Ads1115 286,921 21,800
INA219 Drivers/Ina219 287,001 21,800
SHT3X Drivers/Sht3x 287,037 21,800
MPR121 Drivers/Mpr121 287,693 21,808
PN532+GATEWAY Drivers/NfcGateway 288,129 21,920
core/EthernetW5500 Peripherals/EthernetW5500 469,573 73,672
HISLIP L7-Application/HiSlip 725,197 44,068
LSV2 L7-Application/HeidenhainLsv2 725,481 44,068
SCPI L7-Application/Scpi 725,605 43,812
GPIB L7-Application/Gpib 725,997 43,588
HAAS_MDC L7-Application/HaasMdc 726,081 43,452
DNS_SERVER L7-Application/DnsServer 726,097 46,044
WIFI_SNIFFER+PROMISC Peripherals/WifiSniffer 726,149 43,644
VXI11 L7-Application/Vxi11 726,373 44,196
IKEV2 L5-Session/IKEv2 728,073 43,948
PTP L7-Application/Ptp 728,493 45,020
SNMP+SNMP_TRAP L7-Application/SnmpTrap 728,589 44,988
STATSD L7-Application/StatsdMetrics 728,621 45,148
COAP+COAP_BLOCK+COAP_MAX_PAYLOAD L7-Application/CoapBlock 729,305 49,572
COAP+COAP_OBSERVE L7-Application/CoapObserve 730,573 47,324
UDP_TELEMETRY L7-Application/UdpTelemetry 730,825 45,012
ESPNOW L7-Application/EspNow 731,693 43,580
DNC L7-Application/EthernetDnc 734,029 61,124
HTTP_CLIENT L7-Application/HttpClient 735,577 63,180
SMTP L7-Application/SmtpAlert 735,785 61,124
MQTT L7-Application/MqttClient 736,633 65,340
NTP_SERVER+TIME_SOURCE+NMEA0183+NTP L7-Application/NtpServer 748,837 46,708
ADS L7-Application/AdsClient 753,485 44,204
ACCEPT_THROTTLE L4-Transport/AcceptThrottle 756,209 81,852
core/Basic Foundation/Basic 756,217 81,844
core/CORS L7-Application/CORS 756,409 81,844
core/BasicAuth L6-Presentation/BasicAuth 756,441 81,844
core/DigestAuth L6-Presentation/DigestAuth 756,445 81,844
core/MediaStreaming L7-Application/MediaStreaming 756,505 81,844
RADIO_POWER+RADIO_WIFI_PS L7-Application/RadioPower 756,509 81,844
core/RegexRoutes L7-Application/RegexRoutes 756,561 81,844
KEEPALIVE L4-Transport/KeepAlive 756,589 81,844
DEVICE_ID L7-Application/DeviceUuid 756,645 81,884
core/PathParams L7-Application/PathParams 756,673 81,844
DIFFSERV L4-Transport/DiffServ 756,677 81,844
PER_IP_THROTTLE L4-Transport/PerIpThrottle 756,773 82,292
core/WebSocket L6-Presentation/WebSocket 756,825 81,844
core/ResponseHeaders L7-Application/ResponseHeaders 756,849 81,844
core/Middleware L7-Application/Middleware 756,885 81,844
DIAG L7-Application/Diagnostics 757,037 81,844
core/NetEgress L7-Application/NetEgress 757,097 81,844
GUARDRAILS L7-Application/Guardrails 757,105 81,852
core/FormParams L6-Presentation/FormParams 757,105 81,844
core/ChunkedResponse L7-Application/ChunkedResponse 757,145 81,852
core/ServerSentEvents L6-Presentation/ServerSentEvents 757,261 81,852
AUTH_LOCKOUT L6-Presentation/AuthLockout 757,345 82,420
OTA_ROLLBACK L7-Application/OtaRollback 757,437 81,844
TOTP L7-Application/Totp 757,585 81,876
core/Multipart L6-Presentation/Multipart 757,597 81,844
IP_ALLOWLIST L4-Transport/IpAllowlist 757,793 81,844
LOGBUF L7-Application/LogBuffer 757,917 84,964
core/InterfaceFilter L7-Application/InterfaceFilter 758,049 81,844
SPA_ROUTER L7-Application/SpaFallback 758,193 81,844
core/Templating L7-Application/Templating 758,337 81,876
SIMATIC L7-Application/SimaticSerial 758,481 83,316
MODBUS L7-Application/ModbusTcp 758,533 82,124
STATS L7-Application/Stats 758,541 81,940
CONTROL L7-Application/PidTuning 758,577 89,916
PACKML L7-Application/PackML 758,809 81,884
CSRF L7-Application/Csrf 758,889 83,220
CBOR L6-Presentation/Cbor 758,937 81,916
MODBUS+MODBUS_MASTER L7-Application/ModbusScan 758,977 82,116
IPV6 Foundation/IPv6 759,029 81,844
AUDIT_LOG L7-Application/AuditLog 759,149 84,828
core/Expert Foundation/Expert 759,217 81,860
JWT L6-Presentation/JWTAuth 759,365 84,308
MSGPACK L6-Presentation/MsgPack 760,273 81,916
SYSLOG L7-Application/Syslog 760,365 83,748
AUTH_LOCKOUT+FORWARDED_TRUST L6-Presentation/ForwardedTrust 760,465 82,460
core/Json L6-Presentation/Json 760,489 81,844
STATS+METRICS L7-Application/PrometheusMetrics 760,501 81,980
WS_DEFLATE L6-Presentation/WebSocketCompression 761,193 90,044
CONFIG_STORE+CONFIG_IO L7-Application/ConfigExport 761,461 81,904
OTA L7-Application/OTA 761,917 102,172
DNS_RESOLVER L7-Application/DnsResolver 762,401 83,124
PARTITION_MONITOR L7-Application/PartitionMonitor 762,709 81,844
GRAPHQL L7-Application/GraphQL 762,793 86,252
COAP L7-Application/CoAP 763,717 85,556
TELNET L5-Session/Telnet 764,177 82,372
PROVISIONING L7-Application/Provisioning 764,721 83,472
OPCUA L7-Application/OpcUa 764,773 92,124
core/Advanced Foundation/Advanced 765,177 81,956
TELEMETRY L7-Application/Telemetry 765,285 82,160
SNMP L7-Application/SNMP 765,393 94,292
RELAY L7-Application/PortForward 766,141 116,452
PROMISC+FORWARD+ETHERNET Peripherals/WifiCapture 766,213 47,584
GPIO_MAP L7-Application/GpioMap 766,241 81,900
WEB_TERMINAL L6-Presentation/WebTerminal 766,737 81,924
RTC+TIME_SOURCE+NTP Drivers/Rtc 767,177 45,388
HTTP_CLIENT+WEBHOOK L7-Application/Webhook 767,273 101,596
SMB L7-Application/SmbFileClient 768,029 68,012
OIDC L7-Application/OidcAuth 769,157 99,900
OPCUA+OPCUA_CLIENT L7-Application/OpcUaClient 769,189 94,740
OAUTH2+HTTP_CLIENT L7-Application/OAuth2 769,557 104,668
core/Sysadmin Foundation/Sysadmin 770,377 81,852
OPCUA+UMATI L7-Application/Umati 771,325 92,268
OPCUA+EUROMAP77 L7-Application/Euromap77 771,557 92,292
OPCUA+ROBOTICS L7-Application/Robotics 771,685 92,484
BUS_CAPTURE+FORWARD+ETHERNET Peripherals/CanCapture 772,165 45,568
NTRIP_CASTER L7-Application/NtripCaster 774,721 84,760
NTP+TIME_SOURCE L7-Application/TimeSourceFallback 777,677 83,452
EDGE_CACHE+HTTP_CACHE+HTTP_CLIENT L7-Application/EdgeCache 777,953 119,324
EDGE_CACHE+HTTP_CACHE+HTTP_CLIENT+EDGE_MESH L7-Application/MeshCache 778,433 124,240
MDNS L7-Application/mDNS 781,793 83,752
NTP L7-Application/SNTP 782,189 84,392
EDGE_CACHE+HTTP_CACHE+HTTP_CLIENT+EDGE_MESH+EDGE_CACHE_SLOTS+EDGE_FETCH_SLOTS+MESH_MAX_PEERS L7-Application/MeshCache 782,585 115,380
DASHBOARD L7-Application/Dashboard 783,217 82,212
MDNS+PROMISC+WIFI_SNIFFER+MDNS_ADAPTIVE L7-Application/MdnsAdaptive 783,853 83,832
IFACE_BRIDGE L7-Application/InterfaceBridge 784,405 82,684
COAP+DTLS L7-Application/CoapSecure 787,601 111,964
ETHERNET Peripherals/Ethernet 795,681 81,888
ETHERNET+ETH_W5500+ETH_W5500_CS+ETH_W5500_RST+ETH_W5500_INT+ETH_W5500_SCK+ETH_W5500_MISO+ETH_W5500_MOSI Peripherals/EthernetW5500 795,713 81,888
core/FileServing L7-Application/FileServing 797,713 81,876
UPLOAD L7-Application/FileUpload 798,849 101,988
RANGE L7-Application/Range 798,985 81,876
VFS L7-Application/Vfs 799,825 86,364
WEBDAV L7-Application/WebDav 821,069 105,352
WEBDAV+WEBDAV_MAX_ENTRIES+WEBDAV_BUF_SIZE L7-Application/WebDav 828,613 92,364
WS_CLIENT+TLS+WS_CLIENT_TLS L7-Application/WebSocketClient 831,333 120,548
WS_CLIENT+TLS+WS_CLIENT_TLS+WS_CLIENT_BUF_SIZE L7-Application/WebSocketClient 831,745 123,620
WS_CLIENT+TLS+WS_CLIENT_TLS+WS_CLIENT_BUF_SIZE+TLS_ARENA_SIZE L7-Application/WebSocketClient 832,797 107,272
ETAG L7-Application/ETag 832,909 83,140
SSH L5-Session/SSHHostKey 836,905 112,168
HOTSWAP L7-Application/HotSwapStorage 842,185 82,768
EXC_DECODER+FTP+FTP_SESSION L7-Application/CoreDump 844,789 83,476
HTTP_DELIVERY+FILE_SERVING+RANGE L7-Application/HttpDelivery 846,337 82,752
SSH+SSH_CLIENT+SSH_CLIENT_MAX_CHANNELS+CLIENT_RX_BUF L5-Session/SSHReverseTunnel 852,489 116,640
TLS L6-Presentation/SecureWebSocket 855,873 122,020
TLS+TLS_RESUMPTION L4-Transport/TlsResumption 856,693 122,180
TLS+MTLS L4-Transport/mTLS 856,829 122,356
TLS+TLS_ARENA_SIZE L6-Presentation/SecureWebSocket 861,109 105,712
TLS+TLS_RESUMPTION+TLS_ARENA_SIZE L4-Transport/TlsResumption 861,865 105,864
TLS+MTLS+TLS_ARENA_SIZE L4-Transport/mTLS 861,961 106,040
POWER_MGMT L7-Application/PowerGovernor 885,025 85,696
SSH+FILE_SERVING+SSH_SFTP+SSH_SCP L5-Session/SSHSftp 890,057 121,544

Zero Heap Allocation

Every byte of memory the library uses is accounted for at compile time:

View Zero Heap Allocation Storage Details

Storage Location
conn_pool[MAX_CONNS] - TCP connections + ring buffers BSS
http_pool[MAX_CONNS] - HTTP request structs BSS
ws_pool[MAX_WS_CONNS] - WebSocket connection state BSS
sse_pool[MAX_SSE_CONNS] - SSE connection state BSS
_queue_storage[EVT_QUEUE_DEPTH * sizeof(TcpEvt)] - event queue backing store BSS
_queue_struct - FreeRTOS StaticQueue_t BSS
Route table _routes[MAX_ROUTES] BSS (inside `PC`)

`begin()` calls xQueueCreateStatic() - no pvPortMalloc, no fragmentation risk. The library makes no heap allocations.

The only post-begin() allocation that can occur is inside fs::File construction in serve_file(), which is an Arduino FS implementation detail outside the library's control.

Every pool above is a fixed BSS array sized from the compile-time constants, so the memory cost is exactly what the configuration says - it never grows at runtime. For the measured flash and static-RAM cost of each optional feature, see the Build Footprint table above.

Feature Flags & Configuration

‍[!IMPORTANT] **Use Build Flags (-D...), Not Sketch #defines!**

Because PlatformIO (and standard Arduino IDE builds) compiles the library's source files (.cpp) independently from your sketch (.ino / .cpp), #define macros inside your sketch files do not propagate to the library's pre-compiled objects.

Declaring configuration or feature macros like #define PC_ENABLE_PROVISIONING 1 inside your .ino sketch file before the #include will result in configuration mismatches, linker errors (such as undefined symbols), or unstable behavior at runtime.

To enable/disable features or override configuration constants, you must pass them as compiler build flags. For example, in PlatformIO, define them inside platformio.ini under build_flags:

[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
build_flags =
-DPC_ENABLE_PROVISIONING=1
-DPC_ENABLE_WEBSOCKET=0
-DMAX_CONNS=6

Any feature flag set to 0 strips the corresponding code and its includes from the build entirely.

Feature Flags

The complete set of PC_ENABLE_* flags and their defaults, scraped from src/protocore_config.h by ci_tooling/generate/gen_readme_sections.py (see FEATURES.md for the full description of each):

All feature flags and their defaults

Flag Default Description
PC_ENABLE_ACCEPT_THROTTLE 0 Opt-in global accept-rate throttle (connection-flood defense).
PC_ENABLE_AD9238 0 Enable the AD9238 SPI configuration-port codec (default off).
PC_ENABLE_ADS 0 Beckhoff ADS / AMS protocol codec (services/ads).
PC_ENABLE_ADS1115 0 TI ADS1115 16-bit ADC (I2C) - a precise external analog input.
PC_ENABLE_AMQP 0 AMQP 0-9-1 frame codec (services/amqp).
PC_ENABLE_ATC 0 Opt-in ATC (Advanced Traffic Controller) field-I/O interop snapshot.
PC_ENABLE_AUDIT_LOG 0 Tamper-evident audit log.
PC_ENABLE_AUTH 1 HTTP Basic Authentication per-route.
PC_ENABLE_AUTH_LOCKOUT 0 Opt-in per-IP brute-force lockout for HTTP auth (requires PC_ENABLE_AUTH).
PC_ENABLE_BACNET 0 BACnet/IP BVLC + NPDU codec (services/bacnet).
PC_ENABLE_BLE_GATT 0 Opt-in Bluetooth ATT protocol codec + GATT characteristic bridge.
PC_ENABLE_BUS_CAPTURE 0 Wired field-bus listen-only capture.
PC_ENABLE_C37118 0 IEEE C37.118.2 synchrophasor frame codec (services/c37118).
PC_ENABLE_CANOPEN 0 CANopen (CiA 301) message codec (services/canopen).
PC_ENABLE_CBOR 0 Zero-heap CBOR (RFC 8949) encoder for compact binary payloads.
PC_ENABLE_CC1101 0 Opt-in CC1101 sub-GHz radio driver.
PC_ENABLE_CCLINK 0 Opt-in CC-Link (CLPA) cyclic fieldbus frame codec.
PC_ENABLE_CIA402 0 CiA 402 / IEC 61800-7-201 drive + motion profile (services/cia402).
PC_ENABLE_CIP 0 CIP (Common Industrial Protocol) message codec (services/cip).
PC_ENABLE_CLOUDEVENTS 0 CloudEvents v1.0 (CNCF) event envelope (structured JSON + binary headers).
PC_ENABLE_COAP 0 CoAP server (RFC 7252) over UDP/5683.
PC_ENABLE_COAP_BLOCK 0 CoAP block-wise transfer - RFC 7959 (requires PC_ENABLE_COAP).
PC_ENABLE_COAP_OBSERVE 0 CoAP resource observation - RFC 7641 (requires PC_ENABLE_COAP).
PC_ENABLE_CONFIG_IO 0 Opt-in schema-driven config export / restore.
PC_ENABLE_CONFIG_STORE 0 Typed NVS configuration store (WiFi creds, IP config, ...
PC_ENABLE_CONTROL 0 Closed-loop control law (services/control).
PC_ENABLE_COTP 0 TPKT (RFC 1006) + COTP (X.224 class 0) frame codec (services/cotp).
PC_ENABLE_CSRF 0 Opt-in CSRF protection for state-changing HTTP requests.
PC_ENABLE_DASHBOARD 0 Real-time SVG dashboard (PC_ENABLE_DASHBOARD; requires PC_ENABLE_SSE).
PC_ENABLE_DBM 0 Opt-in dbm: a log-structured hash key-value store on the WAL (PC_ENABLE_DBM, requires WAL).
PC_ENABLE_DDS 0 Opt-in DDS / RTPS wire-protocol codec.
PC_ENABLE_DEVICENET 0 DeviceNet link-adaptation codec (services/devicenet).
PC_ENABLE_DEVICE_ID 0 Stable device UUID derived from the chip MAC (RFC 4122 v5).
PC_ENABLE_DF1 0 Allen-Bradley DF1 full-duplex frame codec (services/df1).
PC_ENABLE_DIAG 0 Expose a diagnostic JSON endpoint via server.diag().
PC_ENABLE_DIFFSERV 0 Enable DiffServ QoS marking (RFC 2474) on outbound traffic.
PC_ENABLE_DIRECTNET 0 Opt-in AutomationDirect / Koyo DirectNET serial frame codec.
PC_ENABLE_DMA 0 Enable the DMA peripheral ingest / egress primitive (default off).
PC_ENABLE_DMX 0 DMX512 + RDM (ANSI E1.20) lighting codec (services/dmx).
PC_ENABLE_DNC 0 Opt-in CNC RS-232 DNC drip-feed codec.
PC_ENABLE_DNP3 0 DNP3 (IEEE 1815) data-link frame codec (services/dnp3).
PC_ENABLE_DNS_RESOLVER 0 Opt-in DNS resolver with answer verification.
PC_ENABLE_DNS_SERVER 0 Authoritative DNS server (services/net/dns_server) on UDP/53.
PC_ENABLE_DOCSTORE 0 Opt-in local JSON document store on the WAL (PC_ENABLE_DOCSTORE, requires DBM + WAL).
PC_ENABLE_DSHOT 0 Opt-in DShot ESC throttle protocol codec.
PC_ENABLE_DTLS 0 DTLS 1.3 datagram security (RFC 9147) - the record layer.
PC_ENABLE_EDGE_CACHE 0 Opt-in CDN edge-cache tier (PC_ENABLE_EDGE_CACHE, requires HTTP_CACHE).
PC_ENABLE_EDGE_MESH 0 Opt-in mesh (sibling-cache) distribution for the edge cache.
PC_ENABLE_EDGE_ORIGIN_TLS 0
PC_ENABLE_ENIP 0 EtherNet/IP encapsulation codec (services/enip).
PC_ENABLE_ENOCEAN 0 Enable the EnOcean ESP3 serial codec (default off).
PC_ENABLE_ESPNOW 0 ESP-NOW peer messaging.
PC_ENABLE_ETAG 0 Conditional GET (ETag + Last-Modified) for served files.
PC_ENABLE_ETHERNET 0 Enable wired Ethernet bring-up (init_eth_physical / eth_ready).
PC_ENABLE_EUROMAP77 0 EUROMAP 77 (OPC 40077) - OPC UA for injection moulding machines (IMM <-> MES).
PC_ENABLE_EXC_DECODER 0 Opt-in ESP32 panic / exception decoder for a live diagnostics panel.
PC_ENABLE_FAILSAFE 0 Opt-in software watchdog: deadlock detection + fail-safe safe-state.
PC_ENABLE_FANUC_J519 0 FANUC Stream Motion (option J519) UDP codec (services/fanuc_j519).
PC_ENABLE_FDC2214 0 Opt-in FDC2114/2214 capacitance-to-digital field sensor.
PC_ENABLE_FILE_SERVING 1 Static file serving via Arduino FS (LittleFS, SPIFFS, SD).
PC_ENABLE_FINS 0 Omron FINS frame codec (services/fins).
PC_ENABLE_FLOW_EXPORT 0 Flow-record export codec (services/flow_export).
PC_ENABLE_FOCAS 0 FANUC FOCAS Ethernet protocol codec (services/focas).
PC_ENABLE_FORWARD 0 Enable the interface forwarding plane (default off).
PC_ENABLE_FORWARDED_TRUST 0 Believe a Forwarded / X-Forwarded-For client address only from a trusted upstream.
PC_ENABLE_FTP 0 Opt-in FTP client wire codec.
PC_ENABLE_FTP_SESSION 0 Opt-in FTP client session driver (PC_ENABLE_FTP_SESSION, requires PC_ENABLE_FTP).
PC_ENABLE_GATEWAY 0 Enable the radio / wireless gateway bridge (default off).
PC_ENABLE_GOOSE 0 Opt-in IEC 61850 GOOSE publisher codec.
PC_ENABLE_GPIB 0 GPIB-over-LAN (Prologix-style) controller command codec (services/gpib).
PC_ENABLE_GPIO_MAP 0 Opt-in browser GPIO pin-mapper / diagnostics endpoint.
PC_ENABLE_GRAPHQL 0 GraphQL query subset.
PC_ENABLE_GRPC_WEB 0 gRPC-Web message framing (services/grpcweb).
PC_ENABLE_GUARDRAILS 0 Opt-in runtime heap/stack guardrails.
PC_ENABLE_HAAS_MDC 0 Haas Machine Data Collection (MDC) Q-command codec (services/haas_mdc).
PC_ENABLE_HAPPY_EYEBALLS 0 Opt-in dual-stack Happy Eyeballs destination selection.
PC_ENABLE_HART 0 Opt-in HART / HART-IP process-instrument protocol codec.
PC_ENABLE_HISLIP 0 HiSLIP (High-Speed LAN Instrument Protocol) message codec (services/hislip).
PC_ENABLE_HMMD 0 Waveshare HMMD 24 GHz mmWave micro-motion radar codec (services/hmmd).
PC_ENABLE_HOSTLINK 0 Omron Host Link (C-mode) frame codec (services/hostlink).
PC_ENABLE_HOTSWAP 0 Opt-in removable-storage hot-swap safeties.
PC_ENABLE_HTTP2 0 HTTP/2 (RFC 9113) over the version-agnostic request/response core.
PC_ENABLE_HTTP3 0 HTTP/3 (RFC 9114) over QUIC (RFC 9000) - implemented, host-tested end-to-end (HW verification pending).
PC_ENABLE_HTTP_CACHE 0 Opt-in HTTP Cache-Control directive helpers.
PC_ENABLE_HTTP_CLIENT 0 Outbound HTTP(S) client (raw lwIP, optional client-side mbedTLS).
PC_ENABLE_HTTP_CLIENT_TLS 0 HTTPS client support inside the HTTP client (needs PC_ENABLE_TLS).
PC_ENABLE_HTTP_DELIVERY 0 Opt-in HTTP delivery optimizations.
PC_ENABLE_HW_HEALTH 0 Opt-in hardware-health diagnostics.
PC_ENABLE_ICCP 0 Opt-in ICCP / TASE.2 (IEC 60870-6) inter-control-center telemetry codec.
PC_ENABLE_IEC60870 0 IEC 60870-5-101 / -104 telecontrol (SCADA) codec (services/iec60870).
PC_ENABLE_IFACE_BRIDGE 0 User-defined address:port -> hardware-bus bridge (services/net/iface_bridge).
PC_ENABLE_IKEV2 0 IKEv2 (RFC 7296) message + payload codec (services/ikev2).
PC_ENABLE_INA219 0 TI INA219 high-side current / power monitor (I2C).
PC_ENABLE_INTERBUS 0 Opt-in INTERBUS summation-frame fieldbus codec.
PC_ENABLE_IOLINK 0 IO-Link (SDCI, IEC 61131-9) data-link message codec (services/iolink).
PC_ENABLE_IPV6 0 Enable IPv6 on the network interface (dual-stack).
PC_ENABLE_IP_ALLOWLIST 0 Opt-in source-IP allowlist (accept-time firewall, IPv4 and IPv6).
PC_ENABLE_J1939 0 SAE J1939 message codec (services/j1939).
PC_ENABLE_J2735 0 Opt-in SAE J2735 V2X codec.
PC_ENABLE_JWT 0 JWT bearer-token authentication (HS256).
PC_ENABLE_KEEPALIVE 1 HTTP/1.1 persistent connections (keep-alive).
PC_ENABLE_LD2410 0 HLK-LD2410 24 GHz mmWave presence / motion radar (UART).
PC_ENABLE_LDC1614 0 Opt-in LDC1614 inductance-to-digital field sensor.
PC_ENABLE_LINK_MANAGER 0 Opt-in multi-interface egress selection / failover policy.
PC_ENABLE_LOGBUF 0 Opt-in fixed-RAM rotating log buffer with severity traps.
PC_ENABLE_LONWORKS 0 Opt-in LonWorks / LON-IP (ISO/IEC 14908) network-variable codec.
PC_ENABLE_LORA 0 Enable the LoRa (SX127x) radio codec + driver (default off).
PC_ENABLE_LSV2 0 Heidenhain LSV/2 telegram codec (services/lsv2).
PC_ENABLE_LWM2M 0 OMA LwM2M TLV codec (services/lwm2m).
PC_ENABLE_MBPLUS 0 Opt-in Modbus Plus HDLC token-bus frame codec.
PC_ENABLE_MBUS 0 Wired M-Bus (Meter-Bus, EN 13757) frame codec (services/mbus).
PC_ENABLE_MDNS 0 mDNS / DNS-SD advertisement (name.local + _http._tcp) via ESPmDNS.
PC_ENABLE_MDNS_ADAPTIVE 0 Opt-in adaptive mDNS beacon scheduling.
PC_ENABLE_MELSEC 0 Mitsubishi MELSEC MC protocol (binary 3E) codec (services/melsec).
PC_ENABLE_METRICS 0 Prometheus /metrics endpoint (text exposition format 0.0.4).
PC_ENABLE_MMS 0 Opt-in IEC 61850 MMS PDU codec.
PC_ENABLE_MODBUS 0 Modbus TCP slave/server (Modbus Application Protocol v1.1b3) on TCP/502.
PC_ENABLE_MODBUS_MASTER 0 Opt-in Modbus master codec + register scanner.
PC_ENABLE_MODBUS_RTU 0 Modbus RTU framing (serial / RS-485) over the same data model + PDU dispatch.
PC_ENABLE_MPR121 0 NXP MPR121 12-channel capacitive-touch controller (I2C).
PC_ENABLE_MQTT 0 MQTT 3.1.1 publish/subscribe client (raw lwIP, optional MQTTS over TLS).
PC_ENABLE_MQTT_SN 0 MQTT-SN v1.2 wire codec (services/iot/mqtt/mqtt_sn).
PC_ENABLE_MQTT_TLS 0 MQTTS: run the MQTT client over client-side TLS (needs PC_ENABLE_TLS).
PC_ENABLE_MSGPACK 0 Zero-heap MessagePack encoder and decoder for compact binary payloads.
PC_ENABLE_MTCONNECT 0 Opt-in MTConnect agent response codec.
PC_ENABLE_MTLS 0 Mutual TLS - require and verify a client certificate (mTLS).
PC_ENABLE_MULTIPART 1 multipart/form-data body parser.
PC_ENABLE_NATS 0 NATS client protocol codec (services/nats).
PC_ENABLE_NEMA_TS2 0 Opt-in NEMA TS 2 traffic-cabinet SDLC frame codec.
PC_ENABLE_NETADAPT 0 Opt-in network adaptation decisions.
PC_ENABLE_NMEA0183 0 NMEA 0183 sentence codec (services/nmea0183).
PC_ENABLE_NMEA2000 0 NMEA 2000 codec (services/nmea2000).
PC_ENABLE_NRF24 0 Enable the nRF24L01+ radio driver (default off).
PC_ENABLE_NTCIP 0 Opt-in NTCIP transportation-device object identifiers.
PC_ENABLE_NTP 0 SNTP wall-clock time sync via the ESP-IDF SNTP client.
PC_ENABLE_NTP_SERVER 0 NTP/SNTP time server (RFC 5905 / RFC 4330 server mode) on UDP/123 (services/pc_ntp_server).
PC_ENABLE_NTRIP_CASTER 0 GNSS RTK base station + NTRIP caster (services/timing_position/gnss).
PC_ENABLE_NTS 0 Opt-in Network Time Security (NTS, RFC 8915) wire codec.
PC_ENABLE_OAUTH2 0 OAuth2 token-endpoint client.
PC_ENABLE_OBSERVABILITY 0 Transport-layer observability: connection event hook + counters.
PC_ENABLE_OCIT 0 Opt-in OCIT-Outstations message codec.
PC_ENABLE_OIDC 0 OpenID Connect ID-token verification, RS256.
PC_ENABLE_OPCUA 0 OPC UA Binary server.
PC_ENABLE_OPCUA_CLIENT 0 OPC UA Binary client.
PC_ENABLE_OPENADR 0 Opt-in OpenADR 3.0 (Automated Demand Response) JSON codec.
PC_ENABLE_OTA 0 Authenticated OTA firmware update (streaming POST to the ESP32 Update API).
PC_ENABLE_OTA_ROLLBACK 0 Opt-in OTA rollback protection / soft-brick safeguard.
PC_ENABLE_PACKML 0 PackML / OMAC packaging-machine state model (services/packml).
PC_ENABLE_PARTITION_MONITOR 0 Opt-in flash partition-map monitor endpoint.
PC_ENABLE_PCA9685 0 NXP PCA9685 16-channel 12-bit PWM / servo driver (I2C).
PC_ENABLE_PER_IP_THROTTLE 0 Opt-in per-IP accept-rate throttle (connection-flood defense, keyed by source IPv4).
PC_ENABLE_PN532 0 Enable the PN532 NFC frame codec (default off).
PC_ENABLE_POWERLINK 0 Opt-in Ethernet POWERLINK (EPSG) basic frame codec.
PC_ENABLE_POWER_MGMT 0 Opt-in SoC power governor.
PC_ENABLE_PQC_KEX 0 Post-quantum hybrid key exchange: ML-KEM-768 + X25519 (FIPS 203 / RFC 9370 combiner).
PC_ENABLE_PREEMPT_QUEUE 0 Enable the preempting work queue primitive (default off).
PC_ENABLE_PROFIBUS 0 Opt-in PROFIBUS-DP FDL telegram codec.
PC_ENABLE_PROFINET 0 Opt-in PROFINET DCP (Discovery and Configuration Protocol) frame codec.
PC_ENABLE_PROMISC 0 Wi-Fi promiscuous (monitor) capture.
PC_ENABLE_PROTOBUF 0 Protocol Buffers wire codec (services/protobuf).
PC_ENABLE_PROVISIONING 0 First-boot WiFi provisioning: softAP + captive-portal credentials form.
PC_ENABLE_PROXY_PROTOCOL 0 HAProxy PROXY protocol codec (services/proxy_protocol).
PC_ENABLE_PSRAM_POOL 0 Opt-in buffer placement policy (DRAM vs PSRAM) + SPI DMA ping-pong manager.
PC_ENABLE_PTP 0 PTP / IEEE 1588-2008 (PTPv2) message codec + slave clock math (services/ptp).
PC_ENABLE_RADIO_POWER 0 Opt-in radio power controls.
PC_ENABLE_RADIO_SNIFF 0 Opt-in receive-only radio channel sniffer to pcap.
PC_ENABLE_RANGE 0 HTTP Range requests / 206 Partial Content (requires PC_ENABLE_FILE_SERVING or PC_ENABLE_EDGE_CACHE).
PC_ENABLE_RAWL2 0 Opt-in raw Layer-2 Ethernet frame codec.
PC_ENABLE_RCWL0516 0 RCWL-0516 microwave Doppler presence sensor + the shared one-GPIO presence facade (services/rcwl0516).
PC_ENABLE_REDIS 0 Redis RESP2 wire codec (services/redis_resp).
PC_ENABLE_REDIS 0 Redis RESP2 wire codec (services/redis_resp).
PC_ENABLE_RELAY 0 Opt-in TCP relay / DNAT port forwarding.
PC_ENABLE_ROAMING 0 Wi-Fi roaming decision layer (services/roaming).
PC_ENABLE_ROBOTICS 0 OPC UA for Robotics information model.
PC_ENABLE_RTC 0 I2C real-time-clock driver (DS1307 / DS3231) - a battery-backed time source.
PC_ENABLE_S7COMM 0 Siemens S7comm PDU codec (services/s7comm).
PC_ENABLE_SAFETY_SCL 0 IEC 61784-3 black-channel Safety Communication Layer primitives (services/safety_scl).
PC_ENABLE_SCPI 0 SCPI / IEEE 488.2 instrument-control codec (services/scpi).
PC_ENABLE_SDI12 0 SDI-12 sensor-bus codec (services/sdi12).
PC_ENABLE_SEN0192 0 DFRobot SEN0192 10.525 GHz microwave Doppler motion sensor (single digital OUT line).
PC_ENABLE_SENML 0 SenML (RFC 8428) measurement-pack builder (services/senml).
PC_ENABLE_SEP2 0 Opt-in IEEE 2030.5 (Smart Energy Profile 2.0) resource codec.
PC_ENABLE_SERCOS 0 Opt-in SERCOS III motion-bus telegram codec.
PC_ENABLE_SHT3X 0 Sensirion SHT3x temperature / humidity sensor (I2C).
PC_ENABLE_SIGFOX 0 Enable the Sigfox AT-command codec (default off).
PC_ENABLE_SIMATIC 0 Siemens SIMATIC serial point-to-point: 3964R link + RK512 telegrams (services/simatic).
PC_ENABLE_SLEEP_SCHED 0 Opt-in dynamic sleep-cycle scheduler.
PC_ENABLE_SMB 0 Opt-in SMB2 client.
PC_ENABLE_SMTP 0 Outbound SMTP client (RFC 5321) for device email alerts (services/net/smtp).
PC_ENABLE_SMTP_TLS 0 Secure SMTP: run the mail client over client-side TLS (needs PC_ENABLE_TLS).
PC_ENABLE_SNMP 0 SNMP agent (v1/v2c, + v3 USM when PC_ENABLE_SNMP_V3) over lwIP UDP.
PC_ENABLE_SNMP_TRAP 0 Outbound SNMP notifications - traps and informs (requires PC_ENABLE_SNMP).
PC_ENABLE_SNMP_V3 0 Add SNMPv3 USM (auth via HMAC-SHA, privacy via AES-128-CFB).
PC_ENABLE_SNP 0 Opt-in GE Fanuc SNP (Series Ninety Protocol) serial frame codec.
PC_ENABLE_SOCKPOOL 0 Opt-in dynamic socket recycling: an LRU connection-slot pool.
PC_ENABLE_SOUTHBOUND 0 Opt-in southbound protocol-driver framework.
PC_ENABLE_SPARKPLUG 0 Sparkplug B payload + topic codec (services/sparkplug).
PC_ENABLE_SPA_ROUTER 0 Opt-in single-page-app micro-routing decision.
PC_ENABLE_SQLITE 0 Opt-in SQLite3 on-disk file-format reader.
PC_ENABLE_SSE 1 Server-Sent Events push support.
PC_ENABLE_SSH 0 SSH server support (RFC 4253/4252/4254).
PC_ENABLE_SSH_CLIENT 0 Outbound SSH client + reverse tunnel (RFC 4254 §7.1 tcpip-forward, the ssh -R seam).
PC_ENABLE_SSH_KEYBOARD_INTERACTIVE 0 SSH keyboard-interactive authentication (RFC 4256), default off.
PC_ENABLE_SSH_SCP 0 SCP server over SSH (the legacy RCP protocol via exec "scp -t/-f").
PC_ENABLE_SSH_SFTP 0 SFTP server subsystem over SSH (SSH_FXP_* v3, draft-ietf-secsh-filexfer-02).
PC_ENABLE_SSH_SNTRUP761 PC_ENABLE_PQC_KEX Streamlined NTRU Prime sntru.nosp@m.p761.nosp@m.x2551.nosp@m.9-sh.nosp@m.a512@.nosp@m.open.nosp@m.ssh.c.nosp@m.om SSH KEX (default: tracks PC_ENABLE_PQC_KEX).
PC_ENABLE_SSH_ZLIB 0 SSH server-to-client compression (zlib@openssh.com / zlib, RFC 4253 sec 6.2).
PC_ENABLE_STATS 0 Runtime stats endpoint (uptime, request/error counts, pool usage, heap).
PC_ENABLE_STATSD 0 Opt-in StatsD metrics client.
PC_ENABLE_STOMP 0 STOMP 1.2 frame codec (services/stomp).
PC_ENABLE_SUNSPEC 0 SunSpec Modbus device-information-model codec (services/sunspec).
PC_ENABLE_SYSLOG 0 Syslog client (RFC 5424 over UDP).
PC_ENABLE_TELEMETRY 0 Telemetry math helpers (moving-window stats, rate-of-change, totalizer).
PC_ENABLE_TELNET 0 Telnet server support (RFC 854 / IAC option negotiation).
PC_ENABLE_THEMES 0 Embed the theme stylesheet library as runtime-selectable blobs (default off).
PC_ENABLE_THREAD 0 Enable the Thread spinel / HDLC-lite framing codec (default off).
PC_ENABLE_TIME_SOURCE 0 Multi-source time fallback (NTP / RTC / GPS / ...
PC_ENABLE_TLS 0 TLS (HTTPS/WSS) via mbedTLS with a static memory pool (ESP32-only).
PC_ENABLE_TLS_POLICY 0 Opt-in TLS version negotiation + pinned cipher-suite policy.
PC_ENABLE_TLS_RESUMPTION 0 TLS session resumption via RFC 5077 session tickets (requires PC_ENABLE_TLS).
PC_ENABLE_TLS_RPK 0 TLS Raw Public Keys (RFC 7250) - present a bare public key instead of an X.509 certificate.
PC_ENABLE_TOTP 0 Opt-in TOTP two-factor auth (RFC 6238).
PC_ENABLE_TRACE_CAPTURE 0 Enable the pre/post-trigger window assembler (default off).
PC_ENABLE_UBX 0 u-blox UBX binary GNSS protocol codec (services/ubx).
PC_ENABLE_UDP_TELEMETRY 0 Opt-in fire-and-forget UDP telemetry cast.
PC_ENABLE_UMATI 0 umati - OPC UA for Machine Tools information model.
PC_ENABLE_UPLOAD 0 Streaming file upload: POST a body straight to a file on the filesystem.
PC_ENABLE_UTMC 0 Opt-in UTMC (Urban Traffic Management and Control) common-database codec.
PC_ENABLE_VFS 0 Unified virtual filesystem wrapper.
PC_ENABLE_VL53L0X 0 Opt-in VL53L0X optical time-of-flight ranging sensor.
PC_ENABLE_VXI11 0 VXI-11 (TCP/IP Instrument Protocol) codec (services/vxi11).
PC_ENABLE_WAL 0 Opt-in write-ahead store for atomic buffer-to-flash storage.
PC_ENABLE_WAMP 0 WAMP messaging codec (services/wamp).
PC_ENABLE_WAVE 0 Opt-in IEEE 1609 WAVE (WSMP + 1609.2 envelope) codec.
PC_ENABLE_WEARLEVEL 0 Opt-in flash wear-leveling slot selector.
PC_ENABLE_WEBDAV 0 WebDAV server (RFC 4918, class 1 + advisory locks) over the file system.
PC_ENABLE_WEBHOOK 0 Opt-in outbound webhooks / IFTTT.
PC_ENABLE_WEBSOCKET 1 WebSocket support (RFC 6455 framing + SHA-1/base64 handshake).
PC_ENABLE_WEB_TERMINAL 0 Browser "web serial" terminal over WebSocket (src/services/web/web_terminal).
PC_ENABLE_WIFI_SNIFFER 0 Opt-in 802.11 sniffer / traffic analyzer.
PC_ENABLE_WISUN 0 Opt-in Wi-SUN FAN border-router connector.
PC_ENABLE_WS_CLIENT 0 Outbound WebSocket client (RFC 6455 over raw lwIP, optional wss:// TLS).
PC_ENABLE_WS_CLIENT_TLS 0 wss://: run the WebSocket client over client-side TLS (needs PC_ENABLE_TLS).
PC_ENABLE_WS_DEFLATE 0 WebSocket permessage-deflate (RFC 7692) - bidirectional compression.
PC_ENABLE_XMPP 0 Opt-in XMPP (RFC 6120) stanza codec.
PC_ENABLE_ZIGBEE 0 Enable the Zigbee EZSP / ASH framing codec (default off).
PC_ENABLE_ZWAVE 0 Enable the Z-Wave Serial API frame codec (default off).

Illegal combinations (e.g. MAX_WS_CONNS + MAX_SSE_CONNS > MAX_CONNS) produce #error messages at compile time with a descriptive reason string.

Configuration Overrides

All constants can be overridden using compiler build flags (e.g. -DMAX_CONNS=6). Default limits and sizes reside in protocore_config.h.

Expand Configuration constants and options

The full list of tunable #define constants and their defaults, scraped from src/protocore_config.h by ci_tooling/generate/gen_readme_sections.py. Override any with a build flag (e.g. -DMAX_CONNS=6); illegal combinations are caught by #error guards at compile time.

Constant Default Description
BODY_BUF_SIZE 256 Maximum request body bytes stored in HttpReq::body.
CACHE_CONTROL_BUF_SIZE 64 Size of the optional Cache-Control header line stored in PC.
CHUNK_BUF_SIZE 1440 Per-chunk staging buffer for send_chunked()'s ChunkSource (max bytes a source produces per call, hence the largest single chunk on the wire).
CONN_TIMEOUT_MS 5000 Compile-time default for connection idle timeout in milliseconds.
CORS_HDR_BUF_SIZE 192 Size of the pre-built CORS header block stored in PC.
DIGEST_AUTH_HDR_MAX 384 Capacity for the full Authorization header value (Digest auth).
EXTRA_HDR_BUF_SIZE 256 Per-connection buffer for app-supplied custom response headers and cookies.
FILE_CHUNK_SIZE 1024 Bytes read from the filesystem and passed to tcp_write() per loop().
JSON_MAX_DEPTH 8 Maximum object/array nesting depth for the JsonWriter (see json.h).
MAX_AUTH_LEN 32 Maximum username or password length for HTTP Basic Authentication.
MAX_BOUNDARY_LEN 72 Maximum MIME boundary length (RFC 2046 allows up to 70 characters).
MAX_CONNS 8 Maximum simultaneous TCP connections (fixed static pool; ~3.95 KB of internal RAM per slot).
MAX_HEADERS 8 Maximum HTTP headers stored per request.
MAX_KEY_LEN 32 Maximum header field-name length (e.g.
MAX_LISTENERS 3 Maximum number of simultaneously active listener ports.
MAX_MIDDLEWARE 4 Maximum globally-registered middleware functions.
MAX_MULTIPART_PARTS 4 Maximum simultaneously parsed multipart parts per request.
MAX_PATH_LEN 64 Maximum URL path length (including leading /).
MAX_PATH_PARAMS 4 Maximum number of :name path parameters captured per route match.
MAX_QUERY_LEN 128 Maximum raw query-string length (everything after ?).
MAX_QUERY_PARAMS 8 Maximum number of parsed query-string parameters.
MAX_ROUTES 16 Maximum simultaneously registered routes.
MAX_SSE_CONNS 2 Maximum simultaneous SSE connections.
MAX_SSH_CONNS 1 Maximum simultaneous SSH connections.
MAX_TELNET_CONNS 2 Maximum simultaneous Telnet connections.
MAX_TLS_CONNS 1 Maximum simultaneous TLS connections (each holds mbedTLS record buffers).
MAX_VAL_LEN 48 Maximum header field-value length.
MAX_WS_CONNS 2 Maximum simultaneous WebSocket connections.
PC_ACCEPT_THROTTLE_MAX 20 Max accepted connections per throttle window (see PC_ENABLE_ACCEPT_THROTTLE).
PC_ACCEPT_THROTTLE_WINDOW_MS 1000 Throttle window length in milliseconds (see PC_ENABLE_ACCEPT_THROTTLE).
PC_ADS1115_DIFFERENTIAL 0 ADS1115 input mode: 0 = single-ended (AINx vs GND), 1 = differential.
PC_ADS1115_I2C_ADDR 0x48 I2C address of the ADS1115 (0x48 with ADDR to GND; 0x49/0x4A/0x4B for VDD/SDA/SCL).
PC_AUTH_LOCKOUT_BASE_MS 1000 First lockout duration in ms; doubles on each further failure.
PC_AUTH_LOCKOUT_MAX_MS 300000 Maximum lockout duration in ms (the exponential backoff cap).
PC_AUTH_LOCKOUT_SLOTS 16 Number of source IPs the auth lockout tracks (BSS bucket table).
PC_AUTH_LOCKOUT_THRESHOLD 5 Consecutive failed auths from one IP before it is locked out.
PC_BASE64_SWAR 1 Use the SWAR base64 decoder (classify 4 characters per 32-bit word).
PC_BRIDGE_MAX_RULES 8 Max concurrent address:port -> bus rules (services/net/iface_bridge).
PC_BRIDGE_STREAM_CHUNK 256 STREAM (UART) pipe chunk size (bytes) for services/net/iface_bridge - one socket<->UART hop.
PC_BRIDGE_TXN_MAX 256 Max write / read payload (bytes) per TRANSACTION frame (services/net/iface_bridge).
PC_BRIDGE_UART_TXN_MS 50 UART TRANSACTION read window (ms): how long a write-then-read waits for the read_len reply.
PC_CLIENT_RX_BUF 8192 Per-connection wire receive ring size (bytes).
PC_CLOSING_TIMEOUT_MS 2000 Upper bound (ms) a slot may dwell in ConnState::CONN_CLOSING after a graceful close before the idle sweep force-aborts it.
PC_COAP_BLOCK1_MAX 1024 Reassembly buffer for a block-wise (Block1) request upload, in bytes.
PC_COAP_BLOCK_SZX_MAX 6 Largest block-size exponent (SZX) the server will use: block size = 2^(SZX+4) bytes, SZX 0..6 (16..1024).
PC_COAP_DEDUP_ENTRIES 4 CoAP message de-duplication cache size (RFC 7252 sec 4.5).
PC_COAP_DEDUP_LIFETIME_MS 247000u How long (ms) a dedup entry stays fresh - RFC 7252 EXCHANGE_LIFETIME (~247 s) by default, past which a repeat Message-ID is treated as a new exchange.
PC_COAP_DEDUP_RESP_MAX 256 Largest cached response the dedup cache retains per entry; a bigger response is not cached (a retransmission re-processes it, fine for the idempotent GET whose block-wise reply exceeds this).
PC_COAP_MAX_OBSERVERS 4 Maximum simultaneous CoAP observers (one slot per observed resource per client).
PC_COAP_MAX_PATH 64 Maximum reconstructed Uri-Path length, including separators and the leading '/'.
PC_COAP_MAX_PAYLOAD 256 Maximum CoAP request/response payload in bytes.
PC_COAP_MAX_QUERY 64 Maximum reconstructed Uri-Query length (segments joined by '&').
PC_COAP_MAX_RESOURCES 8 Maximum registered CoAP resources (the server's fixed routing table).
PC_COAP_OBSERVE_PORT 5683 Default UDP port the CoAP observe transport notifies from (IANA well-known 5683).
PC_CONFIG_KEY_MAX 16 Max key length incl.
PC_CONFIG_MAX_ENTRIES 16 Max key/value entries in the host (test) config backend.
PC_CONFIG_VAL_MAX 64 Max value bytes per entry in the host (test) config backend.
PC_DASHBOARD_JSON_BUF 1024 Stack buffer for the dashboard layout / values JSON (bytes).
PC_DASHBOARD_MAX_WIDGETS 16 Maximum widgets in the dashboard table (BSS value array).
PC_DEBUG_CHECKS 0 Compile the library's internal debug checks (default 0 = off).
PC_DEFER_QUEUE_DEPTH 8 Depth of each worker's deferred-callback queue.
PC_DELIVERY_MANIFEST_BUF 512 Buffer the precache manifest JSON is built into.
PC_DELIVERY_PRECACHE_MAX 16 Most asset paths a service-worker precache manifest may list.
PC_DMA_BUF_SIZE 256 Bytes per DMA transfer buffer (RX is double-buffered at this size).
PC_DMA_CHANNELS 2 Number of DMA channels (static-allocated; each is one peripheral link).
PC_DMA_SIMULATE 1 Route DMA transfers through the ingress/egress simulator (default on).
PC_DNC_LEADER_LEN 32 Default leader/trailer runout length for the DNC encoder.
PC_DNC_LINE_MAX 128 Largest G-code block (one line) the DNC decoder reassembles.
PC_DNC_XOFF_MAX_POLLS 200000 Safety cap on how many times the DNC stream engine polls the reverse channel while paused by an XOFF, before giving up with an I/O error.
PC_DNS_NAME_MAX 128 Max length of a queried/stored DNS name (bytes, incl NUL).
PC_DNS_SERVER_MAX_RECORDS 8 Max A records in the DNS server's fixed table.
PC_DNS_SERVER_TTL 60 TTL (seconds) the DNS server puts on its answers.
PC_DNS_TIMEOUT_MS 5000 DNS resolve timeout in milliseconds.
PC_EDGE_CENC_MAX 32 Stored Content-Encoding to replay (e.g.
PC_EDGE_CTYPE_MAX 64 Stored Content-Type to replay.
PC_EDGE_ETAG_MAX 64 Stored validator (ETag, quotes included).
PC_EDGE_LASTMOD_MAX 40 Stored Last-Modified (RFC 1123 date).
PC_EM77_NS 1 NamespaceIndex the EUROMAP 77 IMM_MES_Interface nodes live at (default 1).
PC_ENFORCE_HOST_HEADER 1 Enforce the RFC 7230 §5.4 Host-header requirement (default on).
PC_ENOCEAN_MAX_DATA 512 Reject an ESP3 telegram whose declared data length exceeds this (framing sanity).
PC_ETH_W5500 0
PC_EXC_COREDUMP_CHUNK 512 Chunk the core-dump image is streamed out of flash in.
PC_FAILSAFE_MAX_LIFELINES 8 Max monitored lifelines in the fail-safe registry (static, zero-heap).
PC_FTP_CHUNK 512 Bytes staged per data-channel write when the session driver streams a payload.
PC_FTP_CMD_MAX 256 Suggested FTP control-command buffer size.
PC_FTP_REPLY_BUF 512 Control-reply accumulator for the FTP session driver.
PC_FTP_TIMEOUT_MS 8000 Per-step timeout for the FTP session driver: connect, and each control reply.
PC_FWD_ACL_PATLEN 4 Bytes an ACL entry can match (its pattern / mask length).
PC_FWD_INSPECT 0 Build-time toggle for the forwarding-path inspection hook (default off, for cost + privacy).
PC_FWD_MAX_ACL 8 Max ingress access-control entries (byte-pattern permit/deny; static).
PC_FWD_MAX_IFACES 4 Max interfaces the forwarding plane tracks (static-allocated).
PC_FWD_MAX_ROUTES 8 Max policy routes (byte-pattern -> egress interface; static).
PC_FWD_MAX_RULES 8 Max forwarding rules (src -> dst allow/deny + rate cap; static-allocated).
PC_GPIO_JSON_BUF 1024 Stack buffer for the GPIO-map JSON (bytes).
PC_GPIO_MAX 40 Maximum GPIO pins the mapper reports (BSS table).
PC_GUARDRAIL_FRAG_MIN_BLOCK 4096 Largest-free-block floor (bytes); below this trips the fragmentation guardrail.
PC_GUARDRAIL_HEAP_MIN 8192 Free-heap floor (bytes); below this trips the heap guardrail.
PC_GUARDRAIL_STACK_MIN 512 Task remaining-stack floor (bytes); below this trips the stack guardrail.
PC_GW_MAX_PORTS 4 Max southbound gateway ports (radios / buses; static-allocated).
PC_H2_HDR_BLOCK 4096 Header-block reassembly buffer for HTTP/2 requests that span HEADERS + CONTINUATION frames (a single END_HEADERS frame decodes in place and needs no copy).
PC_H2_MAX_FRAME 16384 Largest HTTP/2 frame we accept, in bytes (advertised as SETTINGS_MAX_FRAME_SIZE).
PC_H2_MAX_STREAMS 8 Max concurrent HTTP/2 streams per connection (advertised as MAX_CONCURRENT_STREAMS).
PC_H2_POOL_IN_PSRAM 0 Place the HTTP/2 connection-engine pool in external PSRAM (ESP32).
PC_H3_CRYPTO_BUF 2048 Maximum bytes of one QUIC/TLS handshake CRYPTO flight (RFC 9001).
PC_H3_MAX_STREAMS 8 Maximum concurrent request streams per HTTP/3 connection.
PC_HMMD_BAUD 115200 HMMD UART baud rate (the module's factory default is 115200).
PC_HOTSWAP_FAIL_THRESHOLD 3 Consecutive I/O failures that declare a removable volume gone.
PC_HOTSWAP_PROBE_MS 2000 Minimum gap between remount attempts while a volume is absent or faulted (ms).
PC_HPACK_MAX_ENTRIES 128 Max HPACK dynamic-table entries (>= PC_HPACK_TABLE_BYTES / 32, the min entry size).
PC_HPACK_TABLE_BYTES 4096 Per-connection HPACK dynamic-table size in bytes (our decoder; advertised to the peer as SETTINGS_HEADER_TABLE_SIZE).
PC_HTTP3_PORT 443 UDP port the HTTP/3 (QUIC) server binds by default (used by PC::pc_h3_cert).
PC_HTTP_CLIENT_BUF_SIZE 2048 Receive buffer (and max response size) for the outbound HTTP client, bytes.
PC_HTTP_CLIENT_CT_BUF_SIZE 4096 Ciphertext receive-ring size for the https:// client, bytes.
PC_HTTP_CLIENT_TIMEOUT_MS 8000 Outbound HTTP client connect/response timeout in milliseconds.
PC_HTTP_EMIT_DATE 0 Auto-inject a Date response header (RFC 7231 7.1.1.2) when a wall-clock time is available.
PC_INA219_CURRENT_LSB_UA 100 Default INA219 current LSB in microamps per bit (calibration input).
PC_INA219_I2C_ADDR 0x40 I2C address of the INA219 (0x40 default; the A0/A1 pins select 0x40..0x4F).
PC_INA219_SHUNT_MOHM 100 Default INA219 shunt resistance in milliohms (calibration input).
PC_IP_ALLOWLIST_SLOTS 8 Number of CIDR rules the source-IP allowlist can hold (BSS table).
PC_JWT_MAX_LEN 512 Maximum accepted JWT length in bytes (header.payload.signature).
PC_KEEPALIVE_MAX_REQUESTS 100 Maximum requests served on one keep-alive connection before it is closed.
PC_LD2410_BAUD 256000 LD2410 UART baud rate (the module's fixed factory default is 256000).
PC_LOG_LINES 32 Number of log lines retained in the ring.
PC_LOG_LINE_LEN 96 Maximum length of one stored log line (bytes, including null).
PC_LORA_MAX_PAYLOAD 251 Max LoRa payload bytes (SX127x FIFO is 256; RadioHead uses 251 + 4 header).
PC_MAX_UDP_LISTENERS 2 Maximum simultaneously bound UDP ports (transport-layer UDP service).
PC_MODBUS_COILS 64 Number of Modbus coils (FC 1/5/15), single-bit R/W (BSS, bit-packed).
PC_MODBUS_DISCRETE_INPUTS 64 Number of Modbus discrete inputs (FC 2), single-bit read-only (BSS, bit-packed).
PC_MODBUS_HOLDING_REGS 64 Number of Modbus holding registers (FC 3/6/16), 16-bit R/W (BSS).
PC_MODBUS_INPUT_REGS 64 Number of Modbus input registers (FC 4), 16-bit read-only (BSS).
PC_MPR121_I2C_ADDR 0x5A I2C address of the MPR121 (0x5A default; 0x5B/0x5C/0x5D via the ADDR pin).
PC_MPR121_RELEASE_THRESHOLD 6 MPR121 per-electrode release threshold (delta counts; should be below the touch threshold).
PC_MPR121_TOUCH_THRESHOLD 12 MPR121 per-electrode touch threshold (delta counts from baseline; NXP AN3944 suggests ~4..12).
PC_MQTT_BUF_SIZE 1024 MQTT packet buffer size in bytes (bounds one outgoing/incoming packet).
PC_MQTT_CT_BUF_SIZE 4096 Ciphertext receive-ring size for MQTTS (draining ring; must exceed one TCP_MSS).
PC_MQTT_INFLIGHT_BUF 256 Stored-packet size per in-flight QoS 1/2 slot (caps a retransmittable PUBLISH).
PC_MQTT_KEEPALIVE_S 30 Default MQTT keep-alive interval in seconds (PINGREQ cadence / CONNECT field).
PC_MQTT_MAX_INFLIGHT 4 Outbound QoS 1/2 in-flight slots (unacknowledged messages held for DUP retransmit).
PC_MQTT_MAX_TOPIC 128 Maximum inbound MQTT topic length (including NUL) delivered to the callback.
PC_MQTT_RETRANSMIT_MS 5000 Retransmit timeout (ms) for an unacknowledged in-flight QoS 1/2 message.
PC_MQTT_RX_QOS2_SLOTS 8 Inbound QoS 2 packet-id de-duplication ring depth (PUBREC-acknowledged, awaiting PUBREL).
PC_MTLS_SUBJECT_MAX 128 Maximum length of a verified mTLS peer subject DN string (incl.
PC_NEED_CLIENT 0
PC_NRF24_PAYLOAD 32 nRF24 fixed payload width in bytes (1..32; the chip's static payload size).
PC_NTP_SERVER_STRATUM 3 Stratum the NTP server advertises (distance from a reference clock; 1-15).
PC_NTRIP_MAX_MOUNTS 2 Max distinct mountpoints a single caster serves (each = one RTCM stream).
PC_NTRIP_MAX_ROVERS 4 Max concurrent rover connections a caster serves corrections to (services/timing_position/gnss).
PC_NTRIP_MOUNT_MAX 32 Max length (incl.
PC_NTRIP_REQ_MAX 512 Max NTRIP client request size (bytes) the caster buffers while reading the request headers.
PC_OIDC_MAX_LEN 1600 Max accepted OIDC ID-token length (also sizes the Authorization buffer).
PC_OTA_CONFIRM_WINDOW_MS 30000 Confirm window (ms): a pending image not confirmed within this rolls back.
PC_PARTITION_JSON_BUF 1024 Stack buffer for the partition-map JSON (bytes).
PC_PARTITION_MAX 16 Maximum partitions the monitor reports (BSS table).
PC_PCA9685_FREQ 50 Default PWM output frequency in Hz (50 Hz suits hobby servos).
PC_PCA9685_I2C_ADDR 0x40 I2C address of the PCA9685 (0x40 default; the six address pins select 0x40..0x7F).
PC_PER_IP_THROTTLE_MAX 10 Max accepted connections per window from one source IP (see PC_ENABLE_PER_IP_THROTTLE).
PC_PER_IP_THROTTLE_SLOTS 16 Number of source IPv4 addresses tracked by the per-IP throttle (BSS bucket table).
PC_PER_IP_THROTTLE_WINDOW_MS 10000 Per-IP throttle window length in milliseconds (see PC_ENABLE_PER_IP_THROTTLE).
PC_PN532_MAX_DATA 254 Reject a PN532 normal frame whose declared length exceeds this (framing sanity).
PC_POWER_BUSY_PCT 40 Load percentage at/above which the ceiling clock is used.
PC_POWER_MHZ_MAX 240 CPU clock (MHz) when there is work to do.
PC_POWER_MHZ_MIN 80 CPU clock (MHz) when idle, thermally throttled, or recovering from a brownout.
PC_POWER_RECOVER_MS 10000 How long (ms) to hold the floor clock after a brownout reset before ramping back up.
PC_POWER_TEMP_COOL_C 70 Die temperature (C) at/below which the throttle is released.
PC_POWER_TEMP_HOT_C 80 Die temperature (C) at/above which the clock is throttled.
PC_PQ_DEPTH 16 Capacity of the preempting queue in items (static-allocated).
PC_PQ_INTERNAL_PRIORITY 8 Base FreeRTOS priority for the internal preempting lanes (DMA / forwarding / device access).
PC_PQ_ITEM_SIZE 32 Bytes per preempting-queue item (the posted item must fit).
PC_PQ_STACK 4096 Stack (bytes) for each preempting-queue processing task (ESP32).
PC_PROTO_MAX 11 Size of the protocol-handler dispatch table; must exceed the largest ConnProto id.
PC_RADIO_MAX_TX_DBM 0 Max TX power cap in dBm (2..20); 0 = leave the platform default.
PC_RADIO_WIFI_PS 0 WiFi modem-sleep mode: 0 = none (max perf), 1 = min modem, 2 = max modem.
PC_RELAY_BUF 2048 Per-direction relay buffer size (bytes) for services/net/relay.
PC_RELAY_CONNECT_MS 5000 Blocking connect timeout (ms) when the relay listener dials the origin on a new inbound.
PC_RELAY_DRAIN_MAX 8 Max pc_relay_step passes per poll for the relay listener.
PC_RELAY_HOST_MAX 64 Max origin hostname length (bytes, incl.
PC_RELAY_MAX_CONNS 4 Max concurrent relayed connections (bridge table size) for the relay listener.
PC_RELAY_MAX_PUBLISH 4 Max published relay ports (bind table size) for the relay listener.
PC_REQUEST_TIMEOUT_MS 10000 Request-header read deadline in milliseconds (slow-loris defense).
PC_ROBOTICS_AXES 6 Number of Axes the robotics MotionDevice exposes (default 6; must fit PC_OPCUA_REF_MAX).
PC_ROBOTICS_NS 1 NamespaceIndex the robotics MotionDeviceSystem nodes live at (default 1).
PC_RTC_I2C_ADDR 0x68 I2C address of the RTC (DS1307/DS3231 are fixed at 0x68).
PC_SCPI_ERR_QUEUE 8 SCPI error/event queue depth (entries).
PC_SCRATCH_ARENA_SIZE 8192 Size in bytes of the shared per-dispatch scratch arena.
PC_SEN0192_ACTIVE_HIGH 1 SEN0192 OUT polarity: 1 = the OUT line reads HIGH on motion, 0 = active-LOW.
PC_SEN0192_HOLD_MS 2000 Presence is held this many ms after the last active (motion) sample before it clears.
PC_SEN0192_PIN 4 GPIO the SEN0192 OUT line is wired to.
PC_SFTP_MAX_HANDLES 4 Max concurrent open SFTP handles (files + dirs) per SSH connection.
PC_SFTP_MAX_READ 1024 Largest PC_SSH_FXP_DATA payload returned for one READ (a short read - the client re-requests).
PC_SFTP_PATH_MAX 256 Largest absolute path the SFTP/SCP server resolves (mount root + request path).
PC_SFTP_PKT_BUF 2048 SFTP packet-assembly buffer per SFTP channel (bytes); bounds one non-streamed request/response.
PC_SHT3X_I2C_ADDR 0x44 I2C address of the SHT3x (0x44 with ADDR low; 0x45 with ADDR high).
PC_SIGFOX_MAX_PAYLOAD 12 Maximum Sigfox uplink payload (the network caps a message at 12 bytes).
PC_SIMATIC_BLOCK_MAX 256 3964R block-body buffer size (built/received bytes: DLE-stuffed payload + DLE ETX + BCC).
PC_SIMATIC_QVZ_MS 2000 3964R QVZ (Quittungsverzugszeit): handshake acknowledge-delay timeout, ms.
PC_SIMATIC_ZVZ_MS 200 3964R ZVZ (Zeichenverzugszeit): inter-character timeout while receiving a block, ms.
PC_SMB_BUF 1024 SMB2 client work-buffer size (bytes) for smb_client's request/response framing.
PC_SMTP_CT_BUF_SIZE 4096 Ciphertext receive-ring size for SMTPS, bytes (only used when the message is TLS).
PC_SMTP_LINE_MAX 256 Max length of one SMTP command / address line (bytes, incl.
PC_SMTP_MSG_MAX 2048 Max size of the assembled DATA payload (headers + dot-stuffed body), bytes.
PC_SMTP_REPLY_MAX 512 Max size of one (possibly multi-line) server reply held while parsing, bytes.
PC_SMTP_TIMEOUT_MS 10000 SMTP connect / per-reply timeout in milliseconds.
PC_SNMP_TRAP_BUF_SIZE 1024 Static datagram buffer for an outbound SNMP notification, bytes.
PC_SNMP_TRAP_MAX_VARBINDS 8 Maximum extra variable-bindings (beyond sysUpTime/snmpTrapOID) in one notification.
PC_SPB_METRIC_MAX 256 Max serialized size of one Sparkplug B metric submessage (stack temp, bytes).
PC_SSH_ALLOW_PASSWORD 1 Allow SSH password authentication (default on).
PC_SSH_CLIENT_MAX_CHANNELS 4
PC_SSH_FWD_CHUNK 1024 Max bytes moved per forward channel per poll, target -> client (<= SSH_PKT_BUF_SIZE).
PC_SSH_FWD_CONNECT_MS 3000 Blocking connect timeout (ms) when opening a forward target.
PC_SSH_FWD_HOST_MAX 64 Maximum forward target hostname length including null terminator.
PC_SSH_FWD_MAX 2 Maximum concurrent forwarded TCP connections (must be <= PC_CLIENT_CONNS).
PC_SSH_MAX_CHANNELS 1 Maximum concurrent SSH channels per connection (RFC 4254 multiplexing).
PC_SSH_PORT_FORWARD 0 SSH TCP port forwarding (direct-tcpip, i.e.
PC_SSH_RFWD_BRIDGE_MAX 2 Maximum concurrent bridged connections across all remote forwards.
PC_SSH_RFWD_MAX 1 Maximum concurrent remote-forward listeners (ssh -R / tcpip-forward).
PC_SSH_ZLIB_ACK_DRAM 0 Acknowledge placing the SSH compressor in internal DRAM (no PSRAM).
PC_SSH_ZLIB_IN_PSRAM 0 Place the per-connection SSH compression state in external PSRAM (ESP32).
PC_SSH_ZLIB_MAX_IN 2048 Largest uncompressed payload the s2c compressor accepts in one call (bytes).
PC_SSH_ZLIB_WINDOW 8192 SSH s2c DEFLATE sliding-window size in bytes (max back-reference distance).
PC_STATSD_LINE_MAX 256 Stack buffer for one StatsD line (bytes; caps metric name + value + tags).
PC_STATSD_PORT 8125 Default StatsD collector UDP port (StatsD/Graphite standard).
PC_STOMP_MAX_HEADERS 16 Max header lines parsed per STOMP frame (extras beyond this are ignored).
PC_SYSLOG_DEFAULT_PORT 514 Default syslog collector UDP port (RFC 5426 well-known 514; overridable at runtime via pc_syslog_init and here for a non-standard collector).
PC_SYSLOG_FIELD_MAX 32 Maximum syslog HOSTNAME / APP-NAME field length (including NUL).
PC_SYSLOG_MSG_MAX 256 Maximum formatted syslog datagram length in bytes (RFC 5424 line).
PC_TCP_NODELAY 1 Disable Nagle's algorithm (set TCP_NODELAY) on every accepted connection.
PC_TC_MAX_WINDOW_SAMPLES 4096 Max samples a window may hold (pretrigger_samples + posttrigger_samples), static-allocated.
PC_THEMES_INCLUDE_TRADEMARKED 1 Include the trademark-named themes in the embedded set (default on / open-source).
PC_THREAD_MAX_DATA 256 Max spinel payload bytes carried in one HDLC-lite frame.
PC_TIME_SOURCE_MAX 4 Maximum registered time sources.
PC_TLS_ACK_MULTI_CONN_DRAM 0 Acknowledge that a MAX_TLS_CONNS > 1 build has been sized to fit.
PC_TLS_ARENA_IN_PSRAM 0 Place the TLS arena in external PSRAM instead of internal DRAM (ESP32).
PC_TLS_MAX_FRAG_LEN 0 Cap TLS records via the Maximum Fragment Length extension (RFC 6066).
PC_TLS_TICKET_LIFETIME_S 86400 Session-ticket lifetime / key-rotation period in seconds (see PC_ENABLE_TLS_RESUMPTION).
PC_TRUSTED_PROXY_MAX 2 Number of trusted-upstream CIDR rules the forwarded-client resolver holds (BSS table).
PC_UDP_RX_BUF_SIZE 1472 Shared receive-scratch size for the transport-layer UDP service.
PC_UDP_TELEMETRY_BUF 256 Stack buffer for one telemetry line (bytes).
PC_UMATI_NS 1 NamespaceIndex the umati MachineTool nodes live at (default 1).
PC_WEBDAV_BUF_SIZE 2048 Buffer (BSS) for a WebDAV 207 Multi-Status response, in bytes (see PC_ENABLE_WEBDAV).
PC_WEBDAV_MAX_ENTRIES 32 Maximum children listed in a WebDAV Depth-1 PROPFIND (bounds the response).
PC_WEBDAV_MAX_PROPS 16 Maximum properties echoed in a WebDAV PROPPATCH 207 response (bounds the response).
PC_WIFI_SNIFFER_MAX_CHANNELS 14 Channels tracked by the WiFi sniffer's per-channel survey.
PC_WORKER_CORE 1 Core that worker 0 pins to (ESP32).
PC_WORKER_COUNT 1 Number of server worker tasks (slots partitioned i % N).
PC_WORKER_POLL_TICKS 1 Idle-sweep timeout, in FreeRTOS ticks, that a worker blocks between service iterations when no events are pending.
PC_WORKER_STACK_CURVE_MIN 12288 Minimum worker-task stack (bytes) required once SSH is compiled in.
PC_WORKER_STACK_PQC_MIN 16384
PC_WORKER_STACK_RSA_MIN 8192 Minimum worker-task stack (bytes) required once an RSA-2048 verifier is compiled in (OIDC / SSH).
PC_WORKER_TASK_PRIORITY 5 FreeRTOS priority for each server worker task (ESP32).
PC_WORK_AES256CTR 384
PC_WORK_AESCCM 448
PC_WORK_BIGNUM_HW 1024 Worst-case bytes each module borrows from the secure pool in a single call.
PC_WORK_BIGNUM_SW 1408
PC_WORK_CHACHA20 192
PC_WORK_CHACHAPOLY 64
PC_WORK_MD 96
PC_WORK_POLY1305 80
PC_WS_CLIENT_BUF_SIZE 1024 WebSocket client send/receive buffer size in bytes (bounds one frame).
PC_WS_CLIENT_CT_BUF_SIZE 4096 Ciphertext receive-ring size for wss:// (draining ring; must exceed one TCP_MSS).
PC_WS_FRAG_SIZE 0 WebSocket outbound fragmentation size (RFC 6455 sec 5.4), in payload bytes.
PC_ZIGBEE_MAX_DATA 128 Max ASH payload bytes (an EZSP frame; the ASH data field caps near 128).
PC_ZWAVE_MAX_DATA 64 Reject a Z-Wave frame whose declared length exceeds this data cap (sanity).
QUERY_KEY_LEN 24 Maximum query-parameter key length.
QUERY_VAL_LEN 48 Maximum query-parameter value length.
RESP_HDR_BUF_SIZE 768 Stack buffer for HTTP response header lines in send() / send_empty() / send_unauth() / serve_file().
RE_MAX_STEPS 2000 Step budget for the regex route matcher (see on_regex()).
RX_BUF_SIZE 1024 Ring-buffer capacity in bytes per connection slot (feature floors enforced last, in board_drivers/board_profiles/derived_sizing.h - a value below what an enabled feature needs is raised there).
SNMP_COMMUNITY_MAX 32 Maximum SNMP community-string length (including null terminator).
SNMP_MAX_MIB_ENTRIES 16 Maximum registered MIB objects (the agent's fixed OID table).
SNMP_MAX_OID_LEN 32 Maximum sub-identifiers (arcs) in an SNMP object identifier.
SNMP_MAX_VARBINDS 16 Maximum variable bindings the agent will emit in one response.
SNMP_MSG_BUF_SIZE 1472 Static request/response datagram buffers for the SNMP UDP agent.
SNMP_V3_ENGINEID_MAX 32 Maximum SNMPv3 authoritative engine-ID length in bytes (RFC 3411 allows 5..32).
SNMP_V3_USER_MAX 32 Maximum SNMPv3 USM user-name length (including null terminator).
SSE_BUF_SIZE 256 Output buffer size in bytes for a single SSE event.
SSH_AUTH_PASS_MAX 64 Max stored password length.
SSH_AUTH_USER_MAX 32 Max stored user name (RFC 4252 imposes no limit; we cap for BSS).
SSH_CHAN_WINDOW 32768u Initial receive window the SSH server advertises (RFC 4254 §5.1).
SSH_KEXINIT_MAX 2048 Max stored size of the CLIENT KEXINIT payload (I_C, for the exchange hash).
SSH_MAX_AUTH_ATTEMPTS 6 Maximum failed SSH authentication attempts per connection.
SSH_MAX_PASSWORD_LEN 64 Maximum SSH password length including null terminator.
SSH_MAX_USERNAME_LEN 32 Maximum SSH username length including null terminator.
SSH_PKT_BUF_SIZE 2048 Packet assembly buffer per SSH connection (bytes).
SSH_REKEY_PACKET_THRESHOLD 0x40000000u Re-key when either packet sequence number reaches this value.
SSH_REKEY_TIME_MS 3600000u Elapsed-time re-key trigger in milliseconds (RFC 4253 §9: "after each hour").
TELNET_BUF_SIZE 256 Stack buffer for one Telnet I/O chunk.
TERM_TX_BUF_SIZE 256 Stack scratch for pc_web_terminal_frame()/println() line building.
WS_FRAME_SIZE 512 Maximum WebSocket frame payload in bytes.
WS_HDR_BUF_SIZE 256 Stack buffer for the HTTP 101 Switching Protocols response sent during the WebSocket handshake.

Runtime Config

The connection idle timeout can be changed without a rebuild:

const WebServerConfig cfg PROGMEM = { .conn_timeout_ms = 10000 }; // flash, no RAM cost
server.begin(80, &cfg);
WebServerConfig
Runtime-tunable server parameters.
Definition protocore_config.h:6413

Pass nullptr (or omit) to use the compile-time default `CONN_TIMEOUT_MS` (5000 ms).

API Reference

Expand API Reference

PC - Lifecycle

Method Description
begin(port, cfg = nullptr) Bind and listen. Returns PC_OK (1) on success, a negative error code on failure.
`stop()` Abort all connections, close listener, reset all pools.
restart(cfg = nullptr) stop() + begin() on the same port. Returns -1 if called before begin().
`handle()` Call every loop(). Runs timeout sweep, event drain, and dispatch.

PC - HTTP Routes

Method Description
on(path, method, handler) Register a route. Trailing * enables prefix matching.
on(path, method, handler, realm, user, pass) Same, with Basic Auth (PC_ENABLE_AUTH).
on_not_found(handler) Fallback handler; default sends 404.
set_cors(origin) Enable CORS and answer OPTIONS with 204. Pass "" to disable.
send(slot_id, code, type, body) Send a response with body and close the connection.
send_empty(slot_id, code) Send a headers-only response and close the connection.
serve_file(slot_id, fs, path, type) Stream a file from an Arduino FS (PC_ENABLE_FILE_SERVING).

PC - WebSocket (PC_ENABLE_WEBSOCKET)

Method Description
on_ws(path, on_connect, on_message, on_close) Register a WebSocket route.
ws_send_text(ws_id, text) Send a UTF-8 text frame to a client.
ws_send_binary(ws_id, data, len) Send a binary frame to a client.
ws_disconnect(ws_id) Send Close frame and mark slot for cleanup.

In on_message, read the received payload from ws_pool[ws_id].buf (length in ws_pool[ws_id].payload_len).

PC - SSE (PC_ENABLE_SSE)

Method Description
on_sse(path, on_connect) Register an SSE route.
sse_send(sse_id, data, event = nullptr, id = nullptr) Push an event to one client.
sse_broadcast(path, data, event = nullptr, id = nullptr) Push an event to all clients on a path.

PC - Diagnostic (PC_ENABLE_DIAG)

Method Description
diag(slot_id) Send a JSON object with all active feature flags and configuration constants. Disable in production.

Handler Signatures

// HTTP
void handler(uint8_t slot_id, HttpReq *req);
// WebSocket (PC_ENABLE_WEBSOCKET)
void ws_connect(uint8_t ws_id);
void ws_message(uint8_t ws_id); // payload in ws_pool[ws_id].buf
void ws_close(uint8_t ws_id);
// SSE (PC_ENABLE_SSE)
void sse_connect(uint8_t sse_id);
ws_close
void ws_close(WsConn *ws, WsCloseCode code)
Send a Close frame and mark the slot WsParseState::WS_CLOSED.
Definition websocket.cpp:239

HttpReq Fields

Field Type Description
method char[8] HTTP method string, e.g. "GET"
path char[MAX_PATH_LEN] URL path, e.g. "/api/status"
version `HttpVersion` `HTTP_10`, `HTTP_11`, or `HTTP_UNKNOWN`
query char[MAX_QUERY_LEN] Raw query string (everything after ?)
query_params QueryParam[MAX_QUERY_PARAMS] Parsed key=value pairs
query_count uint8_t Valid entries in query_params[]
headers Header[MAX_HEADERS] Captured header fields
header_count uint8_t Valid entries in headers[]
content_length size_t Value of Content-Length header (0 if absent)
body uint8_t[BODY_BUF_SIZE+1] Request body, always null-terminated
body_len size_t Bytes stored in body[]

Helper Functions

const char *http_get_header(const HttpReq *req, const char *key); // case-insensitive
const char *http_get_query (const HttpReq *req, const char *key); // case-sensitive
http_get_header
const char * http_get_header(const HttpReq *req, const char *key)
Look up a header value by name (case-insensitive).
Definition http_parser.cpp:548
http_get_query
const char * http_get_query(const HttpReq *req, const char *key)
Look up a query parameter value by name (case-sensitive).
Definition http_parser.cpp:801

RFC Compliance

The core HTTP/1.1 parser enforces RFC 7230 byte-by-byte; the dispatcher returns the correct status codes (400/404/405/413/414/426/501) with Allow / Sec-WebSocket-Version headers where required; the WebSocket layer enforces RFC 6455 framing. HTTP/2 (RFC 9113 + HPACK RFC 7541) and the HTTP/3 stack (RFC 9114 over QUIC, RFC 9000) follow their own specs, and every optional protocol is implemented against its authoritative standard.

See RFC.md for the HTTP / WebSocket / error-response conformance tables and STANDARDS.md for the complete per-protocol standards map.

SSH Support

ProtoCore includes a complete SSH-2.0 server - banner exchange → KEXINIT negotiation → key exchange → NEWKEYS → user authentication (publickey and password) → ssh-connection session channel, with per-direction NEWKEYS and transparent in-session re-keys. Key exchange offers Curve25519 ECDH (curve25519-sha256) and diffie-hellman-group14-sha256; host keys are Ed25519 (ssh-ed25519) and RSA (rsa-sha2-256 / ssh-rsa). All state is static (BSS), the host private key never touches static scratch memory, and password auth can be compiled out (PC_SSH_ALLOW_PASSWORD=0) for publickey-only hardening.

See SSH.md for the feature summary, RFC/FIPS compliance table, authentication/hardening details, and memory footprint, and SECURITY.md for the security treatment.

Utility Tools

Python tooling for generating documentation and building the embedded web assets. The documentation generators run in CI (the Feature Tables workflow) so their output never drifts; run any of them locally from the repo root.

Expand Utility Tools and Scripts Guide

Documentation generators (ci_tooling/generate/)

Script Generates
gen_feature_tables.py the README / docs feature tables from FEATURES.md
gen_readme_sections.py this file's feature-flag, configuration-override, source-tree, and footprint regions
gen_configurator.py the interactive configurator.html from protocore_config.h
gen_flag_deps.py the build-flag dependency diagram
gen_api_flow.py the core API-flow diagram
gen_examples.py the example index in EXAMPLES.md
decorate_changelog.py wraps each release in CHANGELOG.md in a collapsible block (CI)

The suite's own generator lives with the tests: test/gen_test_readme.py refreshes the env matrix + per-test directory in `test/README.md`.

Web-asset build (web_assets/wizard/)

Script Purpose
build_assets.py compile the editable web sources (web_assets/input/*) into embedded C++ application assets
gen_themes.py build the theme CSS library + gallery from the palette sources
gen_theme_blobs.py pack the runtime-selectable theme CSS into C++ blobs
gen_favicons.py build the favicon library + gallery
python ci_tooling/generate/gen_readme_sections.py # refresh this file's generated sections
python web_assets/wizard/build_assets.py # rebuild the embedded web assets

Testing

2,300+ Unity tests across the native suites, all runnable on a native x86/x64 host (no hardware required). See TEST_REPORT.md for the current per-suite breakdown and totals. Run a representative subset with:

pio test -e native -e native_app -e native_ssh \
-e native_ssh_hardened -e native_ssh_conn -e native_compliance

See the test suite README for the suite breakdown, environment matrix, and per-test directory, and TEST_REPORT.md for the latest results (auto-generated by the Test Report GitHub workflow).

Documentation

Other documentation files in this repository:

View Documentation Reference Directory

The house law - the rules every src/ file obeys. Each states the no-heap guarantee for its own reason; they do not overlap by accident.

Document Contents
SRC_LAW.md The why: determinism and allocation law, derived from MISRA / AUTOSAR
ci_tooling/README.md The tooling law: how generators and checkers must be written, and why.
SRCBANNED.md The what: constructs banned in src/, enforced by a checker
SYMBOLS.md The naming law: prefixes, macros, enums, include guards

Design and conformance:

Document Contents
ARCHITECTURE.md Layering, data piping, ownership, and the multi-vendor design
STANDARDS.md Per-protocol map to the authoritative specification
AUDIT.md Per-standard conformance verdicts and the evidence behind them
INTEROP_MATRIX.md Which features are judged by a third party, and by what
FEATURE_PERFORMANCE.md Per-feature benchmarks, plus conjecture on open work
RFC.md HTTP/1.1, WebSocket, and error-response RFC conformance tables
SSH.md SSH-2.0 server: features, RFC/FIPS compliance, auth, memory
DTLS.md DTLS 1.3 (RFC 9147): TLS for datagrams, for CoAP and telemetry
SECURITY.md Security posture (good/ok/bad) and per-feature treatment
CODEQL.md CodeQL static-analysis setup, coverage, findings disposition
SONARQUBE.md SonarCloud analysis: why it is CI-based, and the compile DB
HARDWARE_HOOKUP.md Wiring and settings for codecs that talk to external hardware
reference/README.md SoC datasheets backing the per-variant board profiles

Generated galleries - regenerated from the tree, never hand-edited:

Document Contents
THEMES.md 112 servable page themes, with previews and the custom recipe
FAVICONS.md 288 favicons, 18 motifs x 16 palettes, as crisp SVG
FOOTPRINTS.md Per-example build footprints (flash and static RAM)

Plan, history, and operations:

Document Contents
ROADMAP.md Unfinished work only: Now / Next / Later / Partial
DELIVERED.md Work that was undertaken and finished
TODO.md Outstanding fixes and maintenance
KNOWN_LIMITATIONS.md Deliberate constraints and caveats
TUNING.md Performance tuning: worker count, core/affinity, poll knobs
test/README.md Test suites, environment matrix, per-test directory, how to run
TEST_REPORT.md Latest test results (auto-generated)
CHANGELOG.md Release history

Generating Docs Locally

To generate the HTML API documentation locally, run the following command from the repository root:

doxygen docs/Doxyfile

The output will be generated in docs/html/index.html.

If you are viewing the offline version of this documentation, you can access the latest online version at the GitHub Pages documentation site.

Licensing & Commercial Use

This library is dual-licensed.

Open Source. This library is, and will ALWAYS REMAIN, FULLY OPEN-SOURCE under the AGPLv3 (or later). We commit to maintaining a fully featured, parity-matched open-source version available to everyone - from hobbyists and educators to professionals - without hiding any non-proprietary (e.g. custom protocols, intellectual property, confidential telemetry configurations, etc.) feature behind a commercial paywall. It will always be free to use under the AGPLv3 (or later) in any environment that complies with the AGPLv3 (or later) terms. See the LICENSE file.

Commercial. For teams and applications that cannot meet the AGPLv3 copyleft requirements, a commercial license is available. Contact: Douglas Quigg (dstroy0), dquig.nosp@m.g123.nosp@m.@gmai.nosp@m.l.co.nosp@m.m

Educators. Teaching with this? We'd love that. SERIOUSLY. Squirty is meant to keep children engaged on the docs page. The docs and styling are set up to appeal to them, hobbyists, and anyone who wants to learn but doesn't know how to style things or glue services together. The library documentation is extensive, extremely thorough, and useful to professionals as well as educators as a teaching tool/classroom prop. If sharing your source under the AGPLv3 isn't practical for a classroom or lab, or you have concerns that have stopped you from using copyleft licensed software before, email Douglas Quigg (dstroy0) at dquig.nosp@m.g123.nosp@m.@gmai.nosp@m.l.co.nosp@m.m from your school address and we'll see what we can do. ESP32 boards are cheap and a hands-on HTTP / IoT-edge stack is a great way into embedded networking, so we're glad to look at education-focused requests one by one. We can't promise an exception for every situation, but please ask. (This is just for genuine educational use; for products, see the commercial option above.) I can help you set up a github repo your students can push to that will help you review their submissions, and walk you through setting up flags for your rubric items. We really need to make an effort to get as many people as possible into the profession, looking at how things work, figuring out how they work on a deeper level, and entering the profession, we need their ideas, we need them now. All great discoveries have come from fresh perspective.

Squirty the Injection Squid
Squirty the Injection Squid: the official library mascot.
Copyright © Douglas Quigg (dstroy0). All rights reserved.