What causes "Bridge register: no session token" in Kuberwastaken/claurst?

Set `session_token` on the `BridgeConfig` before starting the bridge, e.g. from the env var CLAURST_BRIDGE_TOKEN.

Bridge register: no session token

Error message

Bridge register: no session token

What it means

The bridge's `register` method creates a Remote Control session on the claude.ai server, which requires a session token for authentication. If `config.session_token` is `None`, registration cannot proceed and this error is returned. It indicates the bridge was started without complete credentials.

Solutions

Set `session_token` on the `BridgeConfig` before starting the bridge, e.g. from the env var CLAURST_BRIDGE_TOKEN.
Use the higher-level start function that resolves the token from overrides/env (the path at lib.rs:938) instead of constructing `BridgeConfig` by hand.
Re-authenticate to obtain a fresh token from claude.ai (Settings → Remote Control) if the old one was cleared.

Example fix

// before
let config = BridgeConfig { server_url, session_token: None, .. };
// after
let config = BridgeConfig {
    server_url,
    session_token: std::env::var("CLAURST_BRIDGE_TOKEN").ok(),
    ..Default::default()
};

Defensive patterns

Strategy: validation

Validate before calling

// Validate before calling register
if bridge.config.session_token.as_deref().unwrap_or("").is_empty() {
    anyhow::bail!("Set CLAURST_BRIDGE_TOKEN before starting Remote Control");
}

Try / catch

bridge.register().await.inspect_err(|e| {
    if e.to_string().contains("no session token") {
        eprintln!("Enable Remote Control by setting CLAURST_BRIDGE_TOKEN");
    }
})?;

Prevention

Always construct BridgeConfig through a builder/start path that resolves the token from env.
Check for the token at app startup when the Remote Control feature is enabled.
Never build BridgeConfig with session_token: None in production code paths.

When it happens

Trigger: Calling `bridge.register()` (directly or via `start_bridge_with_client` / `run_bridge_loop`) when the `BridgeConfig` was constructed with `session_token: None`.

Common situations: Starting Remote Control without setting CLAURST_BRIDGE_TOKEN; a config builder that skips the token field; token was cleared after logout; wiring the wrong config struct (e.g. main app config instead of bridge config).

Related errors

AI-assisted analysis of Kuberwastaken/claurst@b0637c97ec (2026-09-10). Data as JSON: /api/errors/a2e4e9972a9cfd85. Report an issue: GitHub.

Appendix: source

Thrown at src-rust/crates/bridge/src/lib.rs:448

    fn set_state(&self, s: BridgeState) {
        *self.state.write() = s;
    }

    // -----------------------------------------------------------------------
    // Session registration / deregistration
    // -----------------------------------------------------------------------

    /// Register this bridge session with the CCR server.
    ///
    /// POST `/api/claude_code/sessions` — mirrors the TypeScript
    /// `registerBridgeEnvironment` call in `bridgeApi.ts`.
    pub async fn register(&mut self) -> anyhow::Result<()> {
        let token = self
            .config
            .session_token
            .as_deref()
            .ok_or_else(|| anyhow::anyhow!("Bridge register: no session token"))?;

        let url = format!(
            "{}/api/claude_code/sessions",
            self.config.server_url
        );

        let body = serde_json::json!({
            "session_id": self.session_id,
            "device_id": self.config.device_id,
            "client_version": self.config.runner_version,
        });

        debug!(session_id = %self.session_id, url = %url, "Registering bridge session");

        let resp = self
            .http
            .post(&url)
            .bearer_auth(token)

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