API Evangelist enhancements — MyStars FaaS Fulfilment API

overlay: 1.0.0
info:
  title: API Evangelist enhancements — MyStars FaaS Fulfilment API
  version: 1.0.0
x-provenance:
  generated: '2026-08-27'
  method: generated
  source: openapi/mystars-faas-openapi.json + https://mystars.tg/docs
  extends: openapi/mystars-faas-openapi.json
  note: >-
    Non-destructive enhancements only. The original spec is never mutated. Every value below is
    either derived from the published contract or quoted from the API overview rendered at
    https://mystars.tg/docs — which carries a substantially richer info.description than the
    machine-served /openapi.json does. That gap is the main thing this overlay closes: an agent
    reading only /openapi.json never sees the rate-limit ceilings, the idempotency retry rule,
    or the reversal tolerances, because they live only in the docs-page rendering.
actions:
- target: $.info
  description: Point consumers at the derived artifact set and record the documented runtime semantics missing from the machine-served spec.
  update:
    x-apievangelist-artifacts:
      conventions: conventions/mystars-conventions.yml
      errors: errors/mystars-problem-types.yml
      settlement_outcomes: errors/mystars-decline-codes.yml
      rate_limits: rate-limits/mystars-rate-limits.yml
      lifecycle: lifecycle/mystars-lifecycle.yml
      data_model: data-model/mystars-data-model.yml
      webhooks: asyncapi/mystars-webhooks.yml
      authentication: authentication/mystars-authentication.yml
      packages: packages/mystars-packages.yml
      changelog: changelog/mystars-changelog.yml
    x-rate-limits:
      general: 60 requests/minute per tenant across /v1 reads
      order_lifecycle: 60 requests/minute in a separate bucket for createOrder, getOrder, cancelOrder
      upstream_probe: 60 requests/minute additional cap on getPricing, getPricingBatch, checkRecipient
      headers: [RateLimit-Limit, RateLimit-Remaining, RateLimit-Reset, Retry-After]
      unheadered_429s: daily order cap and per-recipient concurrency guard return the envelope only
    x-money-representation: >-
      All monetary amounts are decimal strings in the unit named by the adjacent *_units /
      currency field. Treat as exact strings; do not parse to float.
- target: $.info
  description: Record that the machine-served spec omits the operational overview published on the docs page.
  update:
    x-docs-parity:
      machine_served_description_chars: 1068
      docs_rendered_description_chars: ~13000
      missing_from_machine_spec: [Quick start, Authentication, Rate limits, Webhooks, Amounts, Idempotency, Errors, 'Reversals & delivery', When a reversal happens]
      recommendation: >-
        Publish the same info.description at /openapi.json and /openapi.yaml that the reference
        page renders, so an agent fetching the contract directly gets the operating rules too.
- target: $.paths['/v1/orders'].post
  description: Annotate the one high-consequence write operation with its reversal path and window.
  update:
    x-consequence: high
    x-idempotent: true
    x-idempotency-header: Idempotency-Key
    x-idempotency-rule: >-
      Same key + identical body replays the original order (200 instead of 201); same key +
      different body is 409. Use a STABLE key equal to your own order id — a new key creates a
      brand-new order and a second charge.
    x-retry-safe-on: [503]
    x-reversibility:
      grade: verified
      reversal_operation: cancelOrder
      window: >-
        While status is awaiting_payment, bounded by the order's expires_at (2 hours since
        v1.12.0). Any other state returns 409.
      post_payment: >-
        No caller-invoked undo, but funds are automatically reversed on-chain minus the network
        fee on payment mismatch (outside -1% .. +2%), undeliverable, or unmatched payment.
- target: $.paths['/v1/orders/{id}/cancel'].post
  description: Record the state precondition as a machine-readable annotation.
  update:
    x-consequence: medium
    x-precondition-status: awaiting_payment
    x-reversibility:
      grade: na
      note: Terminal, but an unpaid cancelled order has nothing to reverse.
- target: $.paths['/v1/recipients/check'].post
  description: Flag the fail-open behaviour, which is easy to misread as a guarantee.
  update:
    x-consequence: none
    x-read-only: true
    x-fail-open: true
    x-caution: >-
      eligible:true with indeterminate:true means the probe could not decide, not that the
      recipient is deliverable. Never present it to a buyer as confirmed.
- target: $.paths['/v1/pricing'].get
  description: Record quote volatility, which the response fields imply but do not state.
  update:
    x-consequence: none
    x-read-only: true
    x-quote-volatility: >-
      The price tracks the market and is recomputed about every minute. quoted_at / valid_until
      are a re-quote hint; the price is locked only when an order is created.
- target: $.webhooks.orderStatus.post
  description: Make the rollover multi-signature rule explicit at the operation level.
  update:
    x-signature-header: X-Faas-Signature
    x-signature-algorithm: HMAC-SHA256 (hex) over the exact raw body
    x-signature-multi-value: >-
      During a 24-hour secret rollover the header carries comma-separated signatures. Parse as a
      list and accept if ANY entry matches — single-value verification silently breaks on the
      first rotation.
    x-receiver-timeout: 5 seconds
    x-follows-redirects: false
- target: $.components.schemas.OrderStatus
  description: Separate terminal from non-terminal states so an agent knows when to stop polling.
  update:
    x-terminal-values: [delivered, failed, reversed, expired, cancelled]
    x-non-terminal-values: [received, awaiting_payment, paid, reserved, swapping, funding, purchasing, fulfilling, completed, held]
    x-cancellable-values: [awaiting_payment]
    x-held-warning: >-
      held is NOT terminal — it means processing or manual review and resolves to delivered or
      reversed. Do not re-create the order.