Kuberwastaken/claurst · error · anyhow::Error

Bridge register: auth error

Error message

Bridge register: auth error ({})

What it means

After `exchange_code` succeeds in `run_mcp_auth_session`, the obtained token is persisted via `store_mcp_token`. If the storage write fails, the error is wrapped as "Failed to store MCP token for '<server>': <e>". It means the OAuth exchange worked but the credentials could not be saved locally, so subsequent sessions would have to re-authenticate.

Solutions

1. Read the wrapped inner error to see whether it is a file permission, disk-space, or serialization problem.
2. Check that the credential/token store location (typically under the user config dir) exists and is writable: `ls -la` and fix ownership/permissions.
3. Free disk space or fix the quota if the write failed due to capacity.
4. If the store file is corrupted, move it aside (back it up) and re-run `run_mcp_auth_flow` to recreate it.

if let Err(e) = run_mcp_auth_flow(&session).await {
    if e.to_string().contains("Failed to store MCP token") {
        eprintln!("Token store unwritable: {} — check permissions/disk space", e);
    }
    return Err(e);
}

When it happens

Trigger: `store_mcp_token(&token)` returns Err — the token store file cannot be opened or written (permissions, disk full, corrupted store), or serialization of `McpToken` fails.

Common situations: Read-only or noexec home/credential directory (CI containers); disk quota exceeded; credential-store file owned by another user or corrupted by a partial previous write.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

• models endpoint returned
• Invalid JWT: expected at least 2 dot-separated segments
• Invalid : contains unsafe characters
• Bridge register: server returned
• Bridge poll: auth error

AI-assisted analysis of Kuberwastaken/claurst@b0637c97ec (2026-09-10). Data as JSON: /api/errors/59247b047fcda8b5. Report an issue: GitHub.

Appendix: source

Thrown at src-rust/crates/bridge/src/lib.rs:483

            .post(&url)
            .bearer_auth(token)
            .header("anthropic-version", "2023-06-01")
            .header("x-environment-runner-version", &self.config.runner_version)
            .json(&body)
            .send()
            .await
            .context("Bridge register: HTTP send failed")?;

        let status = resp.status().as_u16();
        match status {
            200 | 201 => {
                self.set_state(BridgeState::Connected);
                info!(session_id = %self.session_id, "Bridge session registered");
                Ok(())
            }
            401 | 403 => {
                self.set_state(BridgeState::Error(format!("Auth error: {status}")));
                anyhow::bail!("Bridge register: auth error ({})", status)
            }
            _ => {
                anyhow::bail!("Bridge register: server returned {}", status)
            }
        }
    }

    /// Deregister the session on clean shutdown.
    ///
    /// DELETE `/api/claude_code/sessions/{id}` — best-effort; errors are
    /// logged and swallowed so they don't block process exit.
    pub async fn deregister(&self) {
        let Some(token) = self.config.session_token.as_deref() else {
            return;
        };

        let url = format!(
            "{}/api/claude_code/sessions/{}",

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