Error entries

axon:agent:error

All runtime errors arrive as a single entry type. The payload.kind discriminant identifies the specific failure.

type AgentError = ThreadEntry<"axon:agent:error", AnyAgentError>

LLM engine call failed — upstream provider error (503, rate limit, auth, timeout).

{ kind: "engine:error"; message: string; code?: number; engine?: string }

$engine() was called with a name that has no registered engine. Always fatal.

{ kind: "engine:not-found"; message: string; engine: string; available: string[] }

Capsule execution failed — runtime crash, timeout, or policy denial.

{ kind: "capsule:error"; message: string; commandId?: string }

A pathway's middleware chain rejected the request before the handler ran. The pathway did not execute.

{ kind: "middleware:rejected"; message: string; pathway: string; middleware?: string }

The client requested a pathway that does not exist on this agent.

{ kind: "pathway:not-found"; message: string; pathway: string; available: string[] }

An unhandled error escaped the pathway handler and was caught at the server boundary.

{ kind: "pathway:error"; message: string; pathway: string }

Script execution failed — runtime error thrown during axon.run.

{ kind: "script:error"; message: string; script?: string }

Authentication failed or session expired.

{ kind: "auth:error"; message: string }

Client is being rate limited.

{ kind: "rate:error"; message: string; retryAfterMs?: number }

Insufficient Ψ balance to process the request.

{ kind: "balance:error"; message: string; topUpUrl: string }

An agent or capsule operation exceeded its configured time limit.

{ kind: "timeout:error"; message: string; operation?: string; limitMs?: number }