astrid-runtime/astrid · error · GatewayError::Internal

gateway is not wired to a live event bus; agent request stre

Error message

gateway is not wired to a live event bus; agent request stream unavailable

What it means

The GET agent requests SSE handler (get_requests) subscribes to agent request events on the event bus and streams them to the client. This error is thrown when GatewayState.event_bus is None, so there is no bus to subscribe to and no stream can be produced.

Source

Thrown at crates/astrid-gateway/src/routes/agent.rs:399

/// cannot spoof a grant prompt into a user's stream.
#[utoipa::path(
    get,
    path = "/api/agent/requests",
    tag = "agent",
    responses(
        (status = 200, description = "Server-Sent Events stream of pending `approval` and `elicit` requests scoped to the authenticated principal. Starts with `event: ready`.", content_type = "text/event-stream"),
        (status = 401, body = ErrorBody, description = "Missing / invalid bearer."),
        (status = 500, body = ErrorBody, description = "Gateway not wired to a live event bus."),
    )
)]
pub async fn get_requests(
    State(state): State<Arc<GatewayState>>,
    req: Request<axum::body::Body>,
) -> GatewayResult<Sse<impl Stream<Item = Result<Event, Infallible>>>> {
    let caller = caller_from(&req)?.clone();

    let Some(bus) = state.event_bus.clone() else {
        return Err(GatewayError::Internal(anyhow::anyhow!(
            "gateway is not wired to a live event bus; agent request stream unavailable"
        )));
    };

    let conn_route_uuid = Uuid::new_v4();
    let subscribe = |topic: &'static str| {
        bus.subscribe_topic_routed(conn_route_uuid, topic, "gateway", "gateway::agent_requests")
    };
    let mut approval_rx = subscribe("astrid.v1.approval");
    let mut elicit_rx = subscribe("astrid.v1.elicit");
    let principal = caller.principal.to_string();

    let stream = async_stream::stream! {
        yield Ok::<Event, Infallible>(
            Event::default()
                .event("ready")
                .data(serde_json::json!({ "principal": principal }).to_string())
        );

View on GitHub (pinned to affd8760f4)

Solutions

Inject the live event bus into GatewayState during gateway construction and restart
Enable the event bus subsystem in the deployment configuration
If agent streaming is not offered, remove or gate the SSE endpoint for such deployments
Verify the startup logs/health endpoint that the bus is connected before serving agent routes

Example fix

// before
let Some(bus) = state.event_bus.clone() else {
    return Err(GatewayError::Internal(anyhow::anyhow!(
        "gateway is not wired to a live event bus; agent request stream unavailable"
    )));
};
// after: fail fast at startup, not per-request
let bus = config.event_bus.as_ref()
    .ok_or_else(|| anyhow!("event bus required for agent routes"))?;
let state = GatewayState { event_bus: Some(bus.clone()) };

Defensive patterns

Strategy: validation

Validate before calling

// Verify bus availability before opening the SSE stream
pub fn agent_stream_available(state: &GatewayState) -> bool {
    state.event_bus.is_some()
}

Type guard

fn bus_of(state: &GatewayState) -> Option<Arc<EventBus>> {
    state.event_bus.clone()
}

Try / catch

match get_requests(state, req).await {
    Err(GatewayError::Internal(e)) if e.to_string().contains("request stream unavailable") => {
        StatusCode::SERVICE_UNAVAILABLE
    }
    other => other.map(Into::into),
}

Prevention

Wire the bus before mounting the requests SSE route; gate the route on bus presence
Surface bus status in /healthz so operators notice before clients connect
In bus-less deployments (tests/local), stub the SSE route instead of leaving it live
Add an integration test asserting the requests stream works end-to-end when the bus is configured

When it happens

Trigger: Opening the agent request SSE stream when the gateway was built without an event bus (event_bus = None in GatewayState).

Common situations: Gateway launched in a mode without the agent runtime/event bus; misconfiguration that skips bus construction at startup; wiring regression after a refactor of GatewayState initialization; clients pointed at a deployment that intentionally has no agent support.

Understand the failure class

Background: "not installed", "pip install", "required for": how missing-dependency errors surface across open-source libraries — this error's family across 34 libraries.

Related errors

AI-assisted analysis of astrid-runtime/astrid@affd8760f4 (2026-09-09). Data as JSON: /api/errors/61f8b005b566a016. Report an issue: GitHub.