Lambda.Direct

Working example: examples/aws/lambda/direct.yaml.

Use Lambda.Direct when your Lambda receives events that don't fit a more specific handler kind:

• Synchronous SDK invokes (aws lambda invoke, lambda:Invoke from another service, custom clients).
• Step Functions tasks.
• EventBridge Scheduler invocations with no payload transformation.
• Internal admin tooling or ad-hoc RPC.
• A catch-all in a Function that mostly handles HTTP/SQS but occasionally receives unrouted invokes.

Direct is safe to list alongside Lambda.HttpApi and Lambda.Sqs in the same Function — Telo picks the more specific kind whenever it matches, so Direct only catches events nothing else claims.

Minimal example

kind: Lambda.Direct
metadata: { name: Worker }
handler: { kind: My.Worker }
inputs:
  payload: !cel "event"

The handler is invoked with { payload: <the AWS event body> }. Its return value becomes the Lambda's return value (visible to the SDK caller, Step Functions task output, etc.).

With response shaping

returns: and catches: let you reshape the handler's result or render structured errors without touching the handler itself.

kind: Lambda.Direct
metadata: { name: Worker }
handler: { kind: My.Worker }
inputs:
  payload: !cel "event"
returns:
  - when: !cel "result.kind == 'ok'"
    body: !cel "result.value"
  - body: !cel '{ status: "unknown" }'
catches:
  - code: VALIDATION_ERROR
    body: !cel '{ error: { code: error.code, message: error.message } }'

Matching rules:

• returns[] entries are walked top-to-bottom on successful handler return. The first entry whose when: evaluates to true wins; entries without when: are catch-all fallbacks (explicit when matches always beat catch-alls regardless of order).
• catches[] is only consulted when the handler throws an InvokeError. The first entry whose code: matches and when: is truthy wins. If no catch matches, the error propagates to AWS — the caller sees a failed invocation.
• Each matched entry's body: is CEL-expanded against { event, context, result } (success) or { event, context, error } (failure) and returned.
• Omitting returns: entirely returns the handler's result verbatim.

CEL context

Inside	Available
inputs:	event, context
returns[].when / returns[].body	event, context, result
catches[].when / catches[].body	event, context, error (with code, message, data)

When NOT to use Direct

• API Gateway HTTP API v2 events — use Lambda.HttpApi instead.
• SQS batch events — use Lambda.Sqs, which expresses the partial-batch-failure contract.

Direct accepts those events too (it's the catch-all), but you'd be re-implementing the HTTP/SQS-specific bits in your handler.