AINumbers.co Bnpl API

openapi: 3.2.0
info:
  title: AINumbers.co Fintech Intelligence Suite Bnpl API
  version: 1.0.0
  description: '**1255 fintech intelligence tools** covering ISO 20022, A2A payments, CFPB §1033, EU AI Act, DORA, MiCA, AML/KYC, BaaS, DLT/tokenization, ESG/climate finance, agentic payments (AP2, ACP, x402, Visa TAP, Mastercard Agent Pay), PQC migration, sanctions screening, and OpenChainGraph v0.4 computation chains.


    ## Transport


    > **The live transport is MCP JSON-RPC 2.0 at `https://mcp.ainumbers.co/mcp` — not REST.**

    >

    > This OpenAPI file is a **descriptive data-room artifact** — a machine-readable index of all tools and their input/output schemas. The REST paths (`POST /v1/tools/{name}`) described here are a projection; they become functional only if the optional REST shim (Area 2 Path B) is deployed.

    >

    > To call tools today, connect via the official MCP client SDKs. TypeScript: `@modelcontextprotocol/sdk`. Python: `mcp`.


    ## Architecture


    All tools run **entirely client-side** (browser JavaScript). Zero PII. Zero server calls after page load. Deterministic, reproducible outputs. Licensed CC BY 4.0.


    OpenChainGraph v0.4 compute-binding nodes additionally run **server-side on the MCP Worker** and emit verifiable artifacts with `execution_hash` (WebCrypto SHA-256 over RFC 8785 canonical JSON).'
  contact:
    name: Post Oak Labs
    url: https://postoaklabs.com
    email: tim@postoaklabs.com
  license:
    name: CC BY 4.0
    url: https://creativecommons.org/licenses/by/4.0/
servers:
- url: https://ainumbers.co
  description: Static browser-based tool host (DreamHost). Tools run client-side — no REST gateway is active on this origin. See x-mcp for the live MCP endpoint.
tags:
- name: bnpl
paths:
  /v1/tools/compare_bnpl_plans:
    post:
      operationId: compare_bnpl_plans
      summary: BNPL Plan Comparator
      description: 'Side-by-side BNPL plan cost comparison on Reg Z Appendix J APR maths, with every APR computed by art-215 compute_reg_z_appendix_j_apr (imported and delegated to, never reimplemented). Enter a USD principal plus up to 8 plans: a provider preset (labelled examples quoted from dated primary-text snapshots of PayPal, Klarna, Afterpay and Affirm US consumer pages, never an offer) or explicit parameters (instalment count, cadence weekly/biweekly/monthly, stated APR, upfront and per-instalment fees, optional quoted instalment amount). Each plan returns its payment schedule, total of payments, fee total, finance charge and the Reg Z APR of the stream, and the comparison ranks plans by total cost. Terms vary by provider, merchant and credit decision.


        **Tool URL:** https://ainumbers.co/chaingraph/art-779-bnpl-plan-comparator.html

        **AP2/Policy Mandate export:** yes'
      tags:
      - bnpl
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                principal:
                  type: number
                  description: Purchase amount in USD to split across each plan.
                currency:
                  type: string
                  enum:
                  - USD
                  description: Currency; only USD is supported (US consumer terms).
                plans:
                  type: array
                  minItems: 1
                  maxItems: 8
                  description: Plans to compare; preset entries inherit a provider's published plan shape.
                  items:
                    type: object
                    description: 'One plan: either a preset id or explicit parameters, never both.'
                    properties:
                      label:
                        type: string
                        description: Caller's own display label for the plan.
                      preset:
                        type: string
                        description: Snapshot-backed preset id (labelled example, not an offer).
                      num_instalments:
                        type: integer
                        description: Number of instalments, 1 to 156.
                      cadence:
                        type: string
                        enum:
                        - weekly
                        - biweekly
                        - monthly
                        description: Instalment cadence (unit period).
                      apr_pct:
                        type: number
                        description: Stated APR in percent as quoted (0 for interest-free).
                      upfront_fee:
                        type: number
                        description: One-time fee paid at purchase, USD.
                      per_instalment_fee:
                        type: number
                        description: Fee added to every instalment, USD.
                      instalment_amount:
                        type: number
                        description: Quoted instalment amount; required when apr_pct is above 0.
                      down_payment:
                        type: number
                        description: Down payment made at purchase, USD.
                      first_instalment_at_purchase:
                        type: boolean
                        description: True when the first instalment is due at purchase.
                advances:
                  type: array
                loan_amount:
                  type: number
                  default: 0
                num_payments:
                  type: number
                  default: 1
                odd_days:
                  type: number
                  default: 0
                  description: Duration in days
                payment_amount:
                  type: number
                  default: 0
                payments:
                  type: array
                periods_per_year:
                  type: number
                  default: 12
                unit_period_days:
                  type: number
                  default: 30
                  description: Duration in days
              required:
              - principal
              - plans
      responses:
        '200':
          description: Successful tool execution result
          content:
            application/json:
              schema:
                type: object
                description: 'output_payload: input echo, comparison (ranking by total of payments, lowest-total plan indices), per-plan schedule (kind, instalment_no, due_periods_from_purchase, amount), totals, fee total, finance charge, stated APR, reg_z_apr (apr_pct null with flags when no rate is bracketed; computed by art-215), preset provenance (clauses, lender, late-fee note, qualifiers, not-an-offer status), method and terms notes; refusals return domain_error by name.'
      x-mcp-tool-name: compare_bnpl_plans
      x-tool-url: https://ainumbers.co/chaingraph/art-779-bnpl-plan-comparator.html
      x-source: manifest
      x-ap2-export: true
x-mcp:
  transport: MCP JSON-RPC 2.0 (streamable HTTP)
  endpoint: https://mcp.ainumbers.co/mcp
  protocol_version: '2025-11-25'
  authentication: none
  registry: co.ainumbers/tools (official MCP registry)
  note: Connect any MCP-compatible client (Claude, ChatGPT, custom agent) directly to this endpoint. The REST paths in this file are descriptive only — they do not exist on the live server unless the REST shim is deployed.