Primitive

Primitive Payments API

Collect and pay stablecoin (USDC) payments with x402. Settlement is non-custodial: funds move directly from payer to payee on-chain via an EIP-3009 authorization the payer signs with their own key, and Primitive never holds funds. The payee registers a payout address and creates a challenge; the payer signs and settles it under a configurable spend policy (kill-switch, per-payment and per-day caps, payee allowlist).

GitHub OpenAPI

Operations 9

POST /x402/payout-addresses Register a payout address #
GET /x402/payout-addresses List payout addresses #
POST /x402/email-challenges Create an email-native payment challenge #
POST /x402/challenges Create a payment challenge #
GET /x402/challenges/{id} Get a payment challenge #
POST /x402/challenges/{id}/pay Pay a payment challenge #
GET /x402/spend-policy Get your spend policy #
PUT /x402/spend-policy Update your spend policy #
GET /x402/declined-payments List declined payments #

Specifications

⚙
OpenAPI
https://raw.githubusercontent.com/api-evangelist/primitive/refs/heads/main/openapi/primitive-payments-api-openapi.yml

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OpenAPI Specification

primitive-payments-api-openapi.yml Raw ↑ 
openapi: 3.2.0
info:
  title: Primitive Payments API
  version: 1.0.0
  description: Primitive is email infrastructure for AI agents.
  contact:
    name: Primitive
    url: https://primitive.dev
  license:
    name: Proprietary
    url: https://primitive.dev/terms
  x-stability-level: stable
  x-deprecation-policy: 'Breaking changes are announced at least 6 months in advance. Deprecated fields carry x-deprecated: true. The current stable version is v1.'
servers:
- url: https://api.primitive.dev/v1
  description: Canonical API host (PRIMITIVE_API_BASE_URL). Carries every public API operation.
tags:


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# Full source: https://raw.githubusercontent.com/api-evangelist/primitive/refs/heads/main/openapi/primitive-payments-api-openapi.yml