emem Verify Receipt API

openapi: 3.2.0
info:
  description: emem is shared memory for AI agents working together in the real world.
  license:
    name: Apache-2.0
  title: emem Verify Receipt API
  version: 2.4.0
  x-emem-surface-asymmetry:
    memory_notes: MCP only
    reach_them_at: POST /mcp, method tools/call
    read_side_is_here:
    - /v1/memory/search
    - /v1/memory/sse
    - /memories/{path}
    tools:
    - emem_memory_create
    - emem_memory_view
    - emem_memory_delete
    - emem_memory_rename
    - emem_memory_str_replace
    - emem_memory_supersede
    why_not_here: These write the agent correspondence plane, which is prose and untrusted-by-declaration. It is deliberately not part of the REST fact surface, and the two planes are kept apart rather than merged for convenience.
servers:
- description: Hosted instance (HTTPS-only)
  url: https://emem.dev
tags:
- name: Verify Receipt
paths:
  /v1/verify_receipt:
    post:
      description: 'Verify a signed receipt envelope server-side: rebuilds the canonical preimage under the rule the receipt''s own `preimage_version` names, runs ed25519 over the embedded key and signature, and returns `{valid, reason, failure_detail, signature_valid, merkle_proof_valid, signer_pubkey_b32, preimage_blake3_hex}`. A receipt is BYTE-FOR-BYTE OR NOTHING: v2 binds the inclusion proof, so any reshaping (a dropped field, a re-keyed one, a summary) invalidates the signature by design. For when the in-browser /verify path is unavailable, or for a server-side audit of a third party''s receipt.


        When to use: Pass the receipt EXACTLY as the read primitive returned it, whole and unmodified. Two omissions produce a false forgery rather than a 400, and they are the only two worth memorising: dropping `merkle_proof`, and dropping `preimage_version` (absent deserialises to 0, which silently selects the v0 rule, so the proof still walks while the signature reads as invalid). Signature and pubkey may be byte arrays or `sig_b32` / `responder_pubkey_b32`; no other spelling is tolerated. Reshaping a field this responder can check is reported as `reason: receipt_reshaped_after_signing` with the field named, never accepted. Optionally set `pubkey_b32` to assert a specific signer. A bad signature is 200 with `valid: false`, never a 4xx. The example arguments are a real receipt this responder signed (key epoch 0) over one weather fact at Trafalgar Square: run it unchanged and `valid` is true; change any byte and it is not.'
      operationId: emem_verify_receipt
      requestBody:
        content:
          application/json:
            schema:
              properties:
                pubkey_b32:
                  description: Optional override; defaults to receipt.responder_pubkey_b32
                  type: string
                receipt:
                  description: The receipt object returned by any /v1/* response
                  properties:
                    cells:
                      items:
                        type: string
                      type: array
                    fact_cids:
                      items:
                        type: string
                      type: array
                    primitive:
                      type: string
                    request_id:
                      type: string
                    responder_pubkey_b32:
                      type: string
                    served_at:
                      type: string
                    signature_b32:
                      type: string
                  type: object
              required:
              - receipt
              type: object
        required: true
      responses:
        '200':
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/VerifyReceiptResp'
          description: ok
        default:
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorEnvelope'
          description: 'error, the emem.error.v1 envelope. Branch on the stable `code` (see GET /v1/errors), not the message. A malformed or missing-field request body returns `code: invalid_argument` with the offending field named in `message`.'
      summary: 'offline-verify any responder''s receipt (algebra: verify): rebuild the canonical…'
      tags:
      - Verify Receipt
components:
  schemas:
    PubKey:
      description: Ed25519 32-byte public key, base32-nopad-lowercase encoded (52 chars). Returned in receipts and `/.well-known/emem.json`.
      example: 777er3yihgifqmv5hmc2wwmyszgddzderzhsx6rex4yoakwomvka
      type: string
    VerifyReceiptResp:
      description: Response of /v1/verify_receipt. `valid` is the ed25519 signature check; `signer` is the responder pubkey the signature was checked against; `preimage_b64` is the canonical preimage that was hashed and signed, for reproduction in any other ed25519 implementation.
      properties:
        errors:
          items:
            type: string
          type: array
        preimage_b64:
          type: string
        signer:
          $ref: '#/components/schemas/PubKey'
        valid:
          type: boolean
      required:
      - valid
      - signer
      type: object
    ErrorEnvelope:
      description: The `emem.error.v1` failure envelope returned by every endpoint on a 4xx/5xx. Branch on the stable `code` (not the human `message`). See GET /v1/errors for the full code catalog.
      properties:
        code:
          description: Stable machine-readable error code. One of the codes in GET /v1/errors.
          example: invalid_argument
          type: string
        details:
          description: Optional structured recovery hints; present on errors that ship machine-readable next-steps.
          type: object
        message:
          description: Human-readable detail. For invalid_argument this names the offending field (e.g. "missing field `q`").
          type: string
        path:
          description: Request path that produced the error.
          example: /v1/ask
          type: string
        schema:
          const: emem.error.v1
          type: string
      required:
      - code
      - message
      - schema
      type: object