Circle website screenshot

Circle

Circle Internet Financial is the issuer of USDC and EURC and operates a developer platform for moving regulated stablecoin money across the internet. Their APIs cover programmable wallets (developer- and user-controlled), gas sponsorship, the Cross-Chain Transfer Protocol (CCTP), Gateway unified balances, the Smart Contract Platform, the Circle Payments Network (CPN) for cross-border payments, compliance, StableFX trading on Arc, and xReserve for issuing USDC-backed stablecoins.

Circle publishes 6 APIs on the APIs.io network, including NFTs API, Signing API, Tokens API, and 3 more. Tagged areas include Blockchain, Compliance, Cross-Chain, Currency, and Money.

The Circle catalog on APIs.io includes 1 event-driven AsyncAPI specification, 1 JSON-LD context, and 3 Spectral governance rulesets.

Circle’s developer surface includes authentication, developer portal, developer console, getting-started guide, support, engineering blog, and 16 more developer resources.

🌐 Visit website 📡 Source on GitHub
54.3/100 developing ▼ -5.3 Agent 36/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreemiumSelf serve⚡ Free to try
7 APIs
BlockchainComplianceCross-ChainCurrencyMoneyPaymentsStablecoinTransfersUSDCWallets

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 54.3/100 · developing
Contract Quality 17.0 / 25
Developer Ergonomics 8.7 / 20
Commercial Clarity 12.1 / 20
Operational Transparency 6.8 / 13
Governance 5.0 / 12
Discoverability 7.4 / 10
Agent readiness — 36/100 · agent ready
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 6 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
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/circle: 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 7

Individual APIs this provider publishes, each with its own machine-readable definition.

Gas Station and Paymaster

Sponsor gas fees on behalf of users or let users pay gas in USDC via Circle Paymaster, removing native-token friction from onboarding.

Circle NFTs API

The NFTs API from Circle — 1 operation(s) for nfts.

Circle Signing API

The Signing API from Circle — 4 operation(s) for signing.

Circle Tokens API

The Tokens API from Circle — 1 operation(s) for tokens.

Circle Transactions API

The Transactions API from Circle — 12 operation(s) for transactions.

Circle Wallet Sets API

The Wallet Sets API from Circle — 4 operation(s) for wallet sets.

Circle Wallets API

The Wallets API from Circle — 7 operation(s) for wallets.

Scroll for all 7

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Circle Web3 Services (W3S) — Developer-Controlled Wallets API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Circle Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Circle Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Circle Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Circle Webhook Notifications

AsyncAPI description of Circle's outbound webhook (notification) surfaces. Circle delivers event notifications by POSTing a JSON body to a subscriber endpoint that is registered...

ASYNCAPI

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Circle Context

0 classes · 6 properties

JSON-LD

Spectral Rules 3

Spectral governance rulesets for linting and validating these APIs.

Circle API Rules

8 rules · 1 errors 7 warnings

SPECTRAL

Circle API Rules

5 rules · 3 warnings 2 info

SPECTRAL

Circle API Rules

9 rules · 4 errors 4 warnings 1 info

SPECTRAL

JSON Schema 2

Standalone JSON Schema definitions for this provider's data models.

Circle Transaction

17 properties

JSON SCHEMA

Circle Wallet

11 properties

JSON SCHEMA

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Circle Authentication

http · 1 scheme

SECURITY

Circle Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Circle Agentic Access

30 operations · 18 acting · 3 human-in-the-loop

30 operations · 18 acting

AGENTIC

Resources

Get Started 3

Portal, sign-up, and the first successful call

Portal
Portal
 Console
Console
 GettingStarted
GettingStarted

Documentation 3

Reference material describing how the API behaves

JSONSchema
JSONSchema
 JSONSchema
JSONSchema
 AsyncAPI
AsyncAPI

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess
 LlmsText
LlmsText

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

JSONLD
JSONLD
 Spectral
Spectral

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 3

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity
 Authentication
Authentication
 Authentication
Authentication

Operate 3

Status, limits, changes, and where to get help

StatusPage
StatusPage
 Support
Support
 Community
Community

Commercial 2

Pricing, plans, and the legal terms of use

PrivacyPolicy
PrivacyPolicy
 TermsOfService
TermsOfService

Company 3

The organization behind the API

LinkedIn
LinkedIn
 Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: circle
name: Circle
url: https://raw.githubusercontent.com/api-evangelist/circle/refs/heads/main/apis.yml
tags:
- Blockchain
- Compliance
- Cross-Chain
- Currency
- Money
- Payments
- Stablecoin
- Transfers
- USDC
- Wallets
type: Index
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/circle.png
access: 3rd-Party
created: '2024-11-07'
modified: '2026-05-30'
position: Consumer
specificationVersion: '0.19'
description: Circle Internet Financial is the issuer of USDC and EURC and operates a developer platform for moving regulated
  stablecoin money across the internet. Their APIs cover programmable wallets (developer- and user-controlled), gas sponsorship,
  the Cross-Chain Transfer Protocol (CCTP), Gateway unified balances, the Smart Contract Platform, the Circle Payments Network
  (CPN) for cross-border payments, compliance, StableFX trading on Arc, and xReserve for issuing USDC-backed stablecoins.
apis:
- aid: circle:gas-station
  name: Gas Station and Paymaster
  tags:
  - Gas Sponsorship
  - Paymaster
  - USDC
  humanURL: https://developers.circle.com/w3s/gas-station
  baseURL: https://api.circle.com/v1/w3s
  properties:
  - url: https://developers.circle.com/w3s/gas-station
    type: Documentation
  description: Sponsor gas fees on behalf of users or let users pay gas in USDC via Circle Paymaster, removing native-token
    friction from onboarding.
- aid: circle:circle-nfts-api
  name: Circle NFTs API
  description: The NFTs API from Circle — 1 operation(s) for nfts.
  humanURL: https://developers.circle.com/w3s/programmable-wallets
  baseURL: https://api.circle.com/v1/w3s
  tags:
  - NFTs
  properties:
  - type: OpenAPI
    url: openapi/circle-nfts-api-openapi.yml
  - type: Documentation
    url: https://developers.circle.com/w3s/programmable-wallets
  - type: Documentation
    url: https://developers.circle.com/w3s/user-controlled-wallets
  - type: Documentation
    url: https://developers.circle.com/cctp
  - type: Documentation
    url: https://developers.circle.com/gateway
  - type: Documentation
    url: https://developers.circle.com/w3s/smart-contract-platform
  - type: Documentation
    url: https://developers.circle.com/cpn
  - type: Documentation
    url: https://developers.circle.com/w3s/compliance-engine
  - type: Documentation
    url: https://developers.circle.com/stablefx
  - type: Documentation
    url: https://developers.circle.com/xreserve
- aid: circle:circle-signing-api
  name: Circle Signing API
  description: The Signing API from Circle — 4 operation(s) for signing.
  humanURL: https://developers.circle.com/w3s/programmable-wallets
  baseURL: https://api.circle.com/v1/w3s
  tags:
  - Signing
  properties:
  - type: OpenAPI
    url: openapi/circle-signing-api-openapi.yml
  - type: Documentation
    url: https://developers.circle.com/w3s/programmable-wallets
  - type: Documentation
    url: https://developers.circle.com/w3s/user-controlled-wallets
  - type: Documentation
    url: https://developers.circle.com/cctp
  - type: Documentation
    url: https://developers.circle.com/gateway
  - type: Documentation
    url: https://developers.circle.com/w3s/smart-contract-platform
  - type: Documentation
    url: https://developers.circle.com/cpn
  - type: Documentation
    url: https://developers.circle.com/w3s/compliance-engine
  - type: Documentation
    url: https://developers.circle.com/stablefx
  - type: Documentation
    url: https://developers.circle.com/xreserve
- aid: circle:circle-tokens-api
  name: Circle Tokens API
  description: The Tokens API from Circle — 1 operation(s) for tokens.
  humanURL: https://developers.circle.com/w3s/programmable-wallets
  baseURL: https://api.circle.com/v1/w3s
  tags:
  - Tokens
  properties:
  - type: OpenAPI
    url: openapi/circle-tokens-api-openapi.yml
  - type: Documentation
    url: https://developers.circle.com/w3s/programmable-wallets
  - type: Documentation
    url: https://developers.circle.com/w3s/user-controlled-wallets
  - type: Documentation
    url: https://developers.circle.com/cctp
  - type: Documentation
    url: https://developers.circle.com/gateway
  - type: Documentation
    url: https://developers.circle.com/w3s/smart-contract-platform
  - type: Documentation
    url: https://developers.circle.com/cpn
  - type: Documentation
    url: https://developers.circle.com/w3s/compliance-engine
  - type: Documentation
    url: https://developers.circle.com/stablefx
  - type: Documentation
    url: https://developers.circle.com/xreserve
- aid: circle:circle-transactions-api
  name: Circle Transactions API
  description: The Transactions API from Circle — 12 operation(s) for transactions.
  humanURL: https://developers.circle.com/w3s/programmable-wallets
  baseURL: https://api.circle.com/v1/w3s
  tags:
  - Transactions
  properties:
  - type: OpenAPI
    url: openapi/circle-transactions-api-openapi.yml
  - type: Documentation
    url: https://developers.circle.com/w3s/programmable-wallets
  - type: Documentation
    url: https://developers.circle.com/w3s/user-controlled-wallets
  - type: Documentation
    url: https://developers.circle.com/cctp
  - type: Documentation
    url: https://developers.circle.com/gateway
  - type: Documentation
    url: https://developers.circle.com/w3s/smart-contract-platform
  - type: Documentation
    url: https://developers.circle.com/cpn
  - type: Documentation
    url: https://developers.circle.com/w3s/compliance-engine
  - type: Documentation
    url: https://developers.circle.com/stablefx
  - type: Documentation
    url: https://developers.circle.com/xreserve
- aid: circle:circle-wallet-sets-api
  name: Circle Wallet Sets API
  description: The Wallet Sets API from Circle — 4 operation(s) for wallet sets.
  humanURL: https://developers.circle.com/w3s/programmable-wallets
  baseURL: https://api.circle.com/v1/w3s
  tags:
  - Wallet Sets
  properties:
  - type: OpenAPI
    url: openapi/circle-wallet-sets-api-openapi.yml
  - type: Documentation
    url: https://developers.circle.com/w3s/programmable-wallets
  - type: Documentation
    url: https://developers.circle.com/w3s/user-controlled-wallets
  - type: Documentation
    url: https://developers.circle.com/cctp
  - type: Documentation
    url: https://developers.circle.com/gateway
  - type: Documentation
    url: https://developers.circle.com/w3s/smart-contract-platform
  - type: Documentation
    url: https://developers.circle.com/cpn
  - type: Documentation
    url: https://developers.circle.com/w3s/compliance-engine
  - type: Documentation
    url: https://developers.circle.com/stablefx
  - type: Documentation
    url: https://developers.circle.com/xreserve
- aid: circle:circle-wallets-api
  name: Circle Wallets API
  description: The Wallets API from Circle — 7 operation(s) for wallets.
  humanURL: https://developers.circle.com/w3s/programmable-wallets
  baseURL: https://api.circle.com/v1/w3s
  tags:
  - Wallets
  properties:
  - type: OpenAPI
    url: openapi/circle-wallets-api-openapi.yml
  - type: Documentation
    url: https://developers.circle.com/w3s/programmable-wallets
  - type: Documentation
    url: https://developers.circle.com/w3s/user-controlled-wallets
  - type: Documentation
    url: https://developers.circle.com/cctp
  - type: Documentation
    url: https://developers.circle.com/gateway
  - type: Documentation
    url: https://developers.circle.com/w3s/smart-contract-platform
  - type: Documentation
    url: https://developers.circle.com/cpn
  - type: Documentation
    url: https://developers.circle.com/w3s/compliance-engine
  - type: Documentation
    url: https://developers.circle.com/stablefx
  - type: Documentation
    url: https://developers.circle.com/xreserve
common:
- type: AgenticAccess
  url: agentic-access/circle-agentic-access.yml
- type: DomainSecurity
  url: security/circle-domain-security.yml
- type: Authentication
  url: authentication/circle-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/circleco
- type: Website
  url: https://www.circle.com/
- type: Portal
  url: https://developers.circle.com/
- type: Console
  url: https://console.circle.com/
- type: Authentication
  url: https://developers.circle.com/w3s/authentication
- type: GettingStarted
  url: https://developers.circle.com/w3s/getting-started
- type: StatusPage
  url: https://status.circle.com/
- type: Support
  url: https://support.usdc.circle.com/
- type: Blog
  url: https://www.circle.com/blog
- type: Community
  url: https://discord.com/invite/buildoncircle
- type: GitHubOrganization
  url: https://github.com/circlefin
- type: PrivacyPolicy
  url: https://www.circle.com/legal/privacy-policy
- type: TermsOfService
  url: https://www.circle.com/legal/terms-of-service
- type: JSONLD
  url: json-ld/circle-context.jsonld
- type: JSONSchema
  url: json-schema/circle-wallet-schema.json
- type: JSONSchema
  url: json-schema/circle-transaction-schema.json
- type: AsyncAPI
  url: asyncapi/circle-webhooks-asyncapi.yml
- type: Spectral
  url: rules/circle-rules.yml
- type: LlmsText
  url: https://developers.circle.com/llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com