Debugging Runtime Errors

Debugging runtime errors

When a session emits status: failed with a specific error message, the message itself names the contract violation. This skill maps each error pattern to its fix.

Error → fix table

LLM action with outputTo '<doc>' did not call complete

The action set outputTo so the runtime injected a complete tool. The LLM finished without calling it.

Fix: update the agent's prompt to explicitly call complete:

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"When you have the final result, call the `complete` tool with
`{response: '<your final text>'}`. The runtime captures your output
from this call."

See @friday/agent-action-handshake for the full contract.

LLM action with outputTo '<doc>' emitted empty output

The LLM called complete({}). Same fix — the prompt needs to specify what the args should contain.

LLM action with outputTo '<doc>' emitted an empty response

The LLM called complete({response: ""}). Same fix — the prompt needs to populate response with actual content.

LLM step failed: <reason>

The agent called failStep deliberately. Read the reason; it's usually accurate. Either:

• The task was impossible given the agent's tools/inputs → adjust the inputs or the agent's tool surface.
• The agent gave up too easily → tighten the prompt to handle the edge case.

Agent '<agentId>' output does not match <type> schema: ...

The action declared outputType: <type> and the agent's output doesn't match the JSON Schema in documentTypes.<type>. The error message names the specific path that failed validation.

Fix:

• If the schema is wrong → update documentTypes.<type>.
• If the agent's output is wrong → update the agent's prompt to produce data matching the schema, or add an example in the prompt.

Invalid job config: ... (on upsert_job)

Zod rejected the job config on upsert. Common causes:

• execution.agents[] contained inline objects when only string IDs are accepted in Pattern A.
• fsm.states.<state>.entry[] action type was not one of llm, agent, emit, notification.
• outputTo placed on an inline type: llm action without the outer FSM wrapper.

Fix: load @friday/writing-workspace-jobs for the canonical Pattern A vs Pattern B shapes. The error message names the exact path that failed.

Invalid signal config: ... (on upsert_signal)

Zod rejected the signal config. Common cause: missed the inner config: {path: ...} and put path directly on the outer config.

Fix: the shape is

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{
  id: "<signalId>",
  config: {
    provider: "http",
    description: "...",
    config: { path: "/your-path" }
  }
}

See @friday/writing-workspace-signals for templates.

Signal payload validation failed for '<signalId>': ...

The signal declared a JSON Schema and the trigger payload doesn't match.

Fix: match the schema, OR loosen the schema if the new payload shape is correct.

What NOT to do

• Do NOT wrap the failing job in a try/catch and silently retry. These errors are contract violations; retrying without fixing them produces the same error.
• Do NOT migrate Pattern A → Pattern B "to fix" a did not call complete error. That error means the agent prompt is wrong, not the FSM shape.

Cross-references

• @friday/debugging-broken-jobs — the triage entry point.
• @friday/agent-action-handshake — the cross-boundary contract most of these errors violate.
• @friday/writing-workspace-jobs — FSM authoring.
• @friday/writing-workspace-signals — signal config templates.