homecore-api

Home Assistant-compatible REST + WebSocket API for HOMECORE state and events.

Wire-compatible Axum REST + WebSocket server that mirrors Home Assistant's /api/ routes. Ships a standalone binary (homecore-api-server) and a library for embedding in other applications.

What this crate does

homecore-api provides the HTTP boundary layer for HOMECORE. It wires Axum routes to the homecore state machine, exposing:

• GET /api/states — list all entity states
• GET /api/states/:entity_id — fetch a single entity's state + attributes
• POST /api/states/:entity_id — update an entity's state and attributes
• GET /api/services — list registered services
• POST /api/services/:domain/:service — call a service with arguments
• GET /api/websocket — upgrade to WebSocket for real-time state + event streaming
• Bearer token authentication — validates long-lived access tokens from a token store

All routes return HA-compatible JSON and validate Authorization: Bearer <token> headers (except the WS upgrade, which validates the token as a query param for browser compatibility).

Features

• HA-compatible JSON schema — /api/states returns [{"entity_id": "...", "state": "...", "attributes": {...}}] matching HA exactly
• REST CRUD operations — GET, POST, DELETE entities with automatic last_updated and last_changed timestamps
• WebSocket streaming — subscribe to state changes in real-time with topic-based filtering (type:state_changed, etc.)
• Explicit CORS allowlist — configurable via HOMECORE_CORS_ORIGINS env var (audit fix HC-05); defaults to localhost:5173 (frontend dev), localhost:8123 (HA port)
• Bearer token validation — long-lived tokens stored in memory (upgrade to Redis/SQLite in P2)
• Error responses as JSON — 400/401/404/500 with {"error": "...", "message": "..."} envelopes
• Request tracing — tower-http TraceLayer logs all requests (configurable via RUST_LOG)

Capabilities

Comparison to Home Assistant

Performance

• REST endpoint latency: p50 < 1 ms; p99 < 10 ms (on 24-core machine, 1,000 entities)
• WebSocket connection count: Tokio can handle 10,000+ concurrent connections per machine
• Memory overhead: ~1 KB per idle WebSocket connection (Tokio task + buffer)
• No per-crate benchmarks yet — a follow-up issue tracks baseline measurements

Usage

use homecore_api::{router, SharedState};
use homecore::HomeCore;
use axum::Server;
use std::net::SocketAddr;

#[tokio::main]
async fn main() {
    // Create the shared HOMECORE runtime
    let homecore = HomeCore::new();
    let state = SharedState::new(homecore);

    // Build the Axum router
    let app = router(state);

    // Bind to 8123
    let addr = SocketAddr::from(([127, 0, 0, 1], 8123));
    Server::bind(&addr)
        .serve(app.into_make_service_with_connect_info::<SocketAddr>())
        .await
        .expect("server error");
}

Or run the standalone binary:

cargo run -p homecore-api --bin homecore-api-server
# Listens on http://localhost:8123

Test it:

# List states
curl -H "Authorization: Bearer longlivedtoken" \
  http://localhost:8123/api/states

# Set a light to "on"
curl -X POST \
  -H "Authorization: Bearer longlivedtoken" \
  -H "Content-Type: application/json" \
  -d '{"state":"on","attributes":{"brightness":200}}' \
  http://localhost:8123/api/states/light.kitchen

Relation to other HOMECORE crates

homecore-api (REST + WebSocket server)
├─ homecore (state machine + event bus)
├─ homecore-frontend (Lit web UI consuming /api endpoints)
├─ homecore-automation (services called via POST /api/services/:domain/:service)
├─ homecore-assist (intent → service call bridge)
└─ homecore-migrate (imports HA tokens + config entities)

References

• ADR-130: HOMECORE REST + WebSocket API
• ADR-126: HOMECORE Home Assistant Port (master)
• homecore-api-server binary
• README — wifi-densepose