Chain

Chain is a stablecoin payments infrastructure platform that lets enterprises move money globally across both traditional banking rails and digital-currency networks. Its unified REST API covers funding, payouts and payees; virtual and physical card issuing; wallet registration with compliance screening; and a double-entry ledger for reconciliation. Chain connects ACH, Fedwire, FedNow, SEPA, Faster Payments, Visa and Mastercard with multi-stablecoin support (USDC, USDT, USDP, RLUSD) for real-time settlement and payouts to 200+ countries. The platform exposes API-key (Bearer) authentication, an idempotency-key header, webhooks with signature verification, and separate sandbox and live environments for developers.

Chain publishes 1 API on the APIs.io network. Tagged areas include Company, Payments, Stablecoin, Cryptocurrency, and Blockchain.

Chain’s developer surface includes documentation, API reference, getting-started guide, authentication, sandbox, engineering blog, support, and 16 more developer resources.

🌐 Visit website 📡 Source on GitHub
34.4/100 thin ▬ flat Agent 24/100 agent aware Full breakdown ↓
scored 2026-07-21 · rubric v0.4
1 APIs 0 Features
CompanyPaymentsStablecoinCryptocurrencyBlockchainFinancial ServicesWalletsCardsCross-Border PaymentsAPI

API Rating

API Evangelist API Evangelist Rating How this is scored →
scored 2026-07-21 · rubric v0.4
Composite quality — 34.4/100 · thin
Contract Quality 0.0 / 25
Developer Ergonomics 13.0 / 20
Commercial Clarity 6.8 / 20
Operational Transparency 5.8 / 13
Governance 0.0 / 12
Discoverability 8.8 / 10
Agent readiness — 24/100 · agent aware
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/chain: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs

Chain API

Chain's unified REST API for stablecoin payments (funding, payouts, payees), card issuing, wallets, and a double-entry ledger. Bearer API-key auth with sandbox and live key pref...

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 Sandbox
Sandbox
 SignUp
SignUp

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt
LLMsTxt

Design & Contract 4

Pagination, idempotency, versioning, errors, and events

Webhooks
Webhooks
 Conventions
Conventions
 Idempotency
Idempotency
 Lifecycle
Lifecycle

Build 3

SDKs, sample code, and the tooling you integrate with

SDKs
SDKs
 Packages
Packages
 GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication

Operate 3

Status, limits, changes, and where to get help

Support
Support
 ChangeLog
ChangeLog
 StatusPage
StatusPage

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: chain
name: Chain
description: Chain is a stablecoin payments infrastructure platform that lets enterprises move money globally across both
  traditional banking rails and digital-currency networks. Its unified REST API covers funding, payouts and payees; virtual
  and physical card issuing; wallet registration with compliance screening; and a double-entry ledger for reconciliation.
  Chain connects ACH, Fedwire, FedNow, SEPA, Faster Payments, Visa and Mastercard with multi-stablecoin support (USDC, USDT,
  USDP, RLUSD) for real-time settlement and payouts to 200+ countries. The platform exposes API-key (Bearer) authentication,
  an idempotency-key header, webhooks with signature verification, and separate sandbox and live environments for developers.
url: https://raw.githubusercontent.com/api-evangelist/chain/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- 500-global
- pantera-capital
x-tier: stub
x-tier-reason: portfolio-lead
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-18'
tags:
- Company
- Payments
- Stablecoin
- Cryptocurrency
- Blockchain
- Financial Services
- Wallets
- Cards
- Cross-Border Payments
- API
apis:
- name: Chain API
  description: Chain's unified REST API for stablecoin payments (funding, payouts, payees), card issuing, wallets, and a double-entry
    ledger. Bearer API-key auth with sandbox and live key prefixes (sk_sandbox_ / sk_live_) and an X-Idempotency-Key header
    for safe retries.
  humanURL: https://chain.com/documentation
  baseURL: https://api.chain.com/v1
  properties:
  - type: Documentation
    url: https://chain.com/documentation
  - type: Authentication
    url: https://chain.com/documentation/authentication
  - type: Webhooks
    url: https://chain.com/documentation/webhooks
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: DomainSecurity
  url: security/chain-domain-security.yml
- type: Website
  url: https://chain.com
- type: DeveloperPortal
  url: https://chain.com/documentation
- type: Documentation
  url: https://chain.com/documentation
- type: APIReference
  url: https://chain.com/documentation
- type: GettingStarted
  url: https://chain.com/documentation
- type: Authentication
  url: authentication/chain-authentication.yml
- type: Webhooks
  url: https://chain.com/documentation/webhooks
- type: SDKs
  url: https://chain.com/documentation/sdks
- type: Packages
  url: packages/chain-packages.yml
- type: Conventions
  url: conventions/chain-conventions.yml
- type: Idempotency
  url: conventions/chain-conventions.yml
- type: Lifecycle
  url: lifecycle/chain-lifecycle.yml
- type: Sandbox
  url: sandbox/chain-sandbox.yml
- type: LLMsTxt
  url: llms/chain-llms.txt
- type: Blog
  url: https://chain.com/blog
- type: Support
  url: https://chain.com/support
- type: ChangeLog
  url: https://chain.com/developers/changelog
- type: StatusPage
  url: https://chain.com/developers/status
- type: GitHubOrganization
  url: https://github.com/chain
- type: SignUp
  url: https://app.chain.com
- type: TermsOfService
  url: https://chain.com/terms
- type: PrivacyPolicy
  url: https://chain.com/privacy-policy
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence