# Payments AI Developer Docs — Agent Index

Site: https://doc.managed.payments.ai
OpenAPI (Merchant Public API + buyer checkout): https://doc.managed.payments.ai/openapi-public.json

## Agent discovery

- Skill: /SKILL.md
- Agent auth: /auth.md
- Full agent index: /llms-full.txt
- Agent Skills index: /.well-known/agent-skills/index.json
- MCP Server Card: https://managed.payments.ai/.well-known/mcp/server-card.json
- MCP endpoint: https://managed.payments.ai/api/mcp

## Key pages

- Quickstart: /quickstart (create merchant → API key → product+plan → checkout URL)
- Embedded checkout: /embedded-checkout (one plan, payment fields on your page, no server code)
- Custom amount checkout: /custom-amount-checkout (your server charges a price it works out)
- Order checkout: /multi-item-checkout (several items in one payment)
- Merchant Public API: /public-api
- Partner Onboarding: /partner-onboarding (POST /v1/public-api/merchants; assign team with POST …/members when ownerAttached is false)
- MCP server: /mcp
- Webhooks: /webhooks
- API Reference: /api
- Error catalog: /errors
- Getting help: /getting-help

## Sandbox

- API base URL: https://sandbox.managed.payments.ai/api
- Merchant Public API prefix: /v1/public-api/merchants/{merchantId}/…
- Partner onboarding: POST /v1/public-api/merchants (Bearer pai_test_* / pai_live_*; parent derived from the key)
- Buyer checkout (no key): /v1/checkout/plans/{planId}/… — includes POST …/confirm used by the embed
- Auth: Bearer pai_test_* (64 hex chars after prefix)
- Live keys (pai_live_*) are blocked in docs Try It Safe Mode

## Error docUrl pattern

https://doc.managed.payments.ai/errors/{slug}
slug = code with `.` and `_` replaced by `-`, lowercased