MIDAS External Event Contract

asyncapi: 3.0.0
info:
  title: MIDAS External Event Contract
  version: v1
  description: >-
    External event contract for MIDAS decision governance. Events are written to a
    transactional outbox in the same Postgres transaction as domain state changes, then
    dispatched to Kafka by a background dispatcher (at-least-once delivery; consumers must
    dedupe on event_id). Two external event types are defined. Modelled by API Evangelist
    from docs/events.md and docs/examples/events/ (schema contract), not published by the
    vendor as AsyncAPI.
  contact:
    name: Accept Labs
    url: https://www.accept.io
  license:
    name: Apache-2.0
  x-apievangelist-generated: '2026-07-18'
  x-apievangelist-method: searched
  x-apievangelist-source: https://github.com/accept-io/midas/blob/main/docs/events.md
servers:
  kafka:
    host: your-kafka-broker:9092
    protocol: kafka
    description: Kafka broker(s) configured via MIDAS_KAFKA_BROKERS; enabled when MIDAS_DISPATCHER_ENABLED=true.
channels:
  decisions:
    address: midas.decisions
    description: Decision lifecycle events. Partition key is {request_source}:{request_id}.
    messages:
      outcomeRecorded:
        $ref: '#/components/messages/DecisionOutcomeRecorded'
      envelopeClosed:
        $ref: '#/components/messages/DecisionEnvelopeClosed'
operations:
  receiveOutcomeRecorded:
    action: receive
    channel:
      $ref: '#/channels/decisions'
    messages:
    - $ref: '#/channels/decisions/messages/outcomeRecorded'
  receiveEnvelopeClosed:
    action: receive
    channel:
      $ref: '#/channels/decisions'
    messages:
    - $ref: '#/channels/decisions/messages/envelopeClosed'
components:
  messages:
    DecisionOutcomeRecorded:
      name: decision.outcome_recorded
      title: Decision outcome recorded
      summary: Emitted when an evaluation produces a terminal outcome (accept, escalate, reject, request_clarification).
      contentType: application/json
      payload:
        $ref: '#/components/schemas/EventEnvelope'
      examples:
      - name: outcomeRecorded
        payload:
          schema_version: v1
          event_id: 7f3a2b1e-0c4d-4e5f-9a8b-1c2d3e4f5a6b
          type: decision.outcome_recorded
          occurred_at: '2025-11-15T14:32:00.123Z'
          envelope_id: e1b2c3d4-5678-90ab-cdef-1234567890ab
          payload:
            request_source: svc:payments
            request_id: req-abc-001
            surface_id: payments-gateway
            agent_id: agent-payments-prod
            outcome: accept
            reason_code: WITHIN_AUTHORITY
    DecisionEnvelopeClosed:
      name: decision.envelope_closed
      title: Decision envelope closed
      summary: Emitted when a governance envelope reaches closed state; includes an optional review object for escalated envelopes.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/EventEnvelope'
      examples:
      - name: envelopeClosed
        payload:
          schema_version: v1
          event_id: b9c8d7e6-f5a4-3210-9876-fedcba987654
          type: decision.envelope_closed
          occurred_at: '2025-11-15T16:45:12.500Z'
          envelope_id: f2e3d4c5-6789-01bc-defa-234567890abc
          payload:
            request_source: svc:payments
            request_id: req-def-002
            final_outcome: escalate
            closed_at: '2025-11-15T16:45:12.500Z'
            review:
              decision: APPROVED
              reviewer_id: human:alice
              reviewer_kind: human
              notes: Action reviewed and approved by on-call engineer
  schemas:
    EventEnvelope:
      type: object
      required: [schema_version, event_id, type, occurred_at, envelope_id, payload]
      properties:
        schema_version:
          type: string
          const: v1
        event_id:
          type: string
          format: uuid
          description: Deduplication key; consumers must be idempotent on this value.
        type:
          type: string
          enum: [decision.outcome_recorded, decision.envelope_closed]
        occurred_at:
          type: string
          format: date-time
        envelope_id:
          type: string
          format: uuid
        payload:
          type: object
          additionalProperties: true