Loop Crypto

Loop Crypto is a crypto and stablecoin payment processor that lets merchants, billing software, and e-commerce platforms accept crypto and stablecoin payments end to end: charging a wallet, storing payment methods, accepting stablecoins, ERC-20 tokens, and Solana SPL tokens, and settling to merchants in either fiat or crypto. Loop offers payment links, an embeddable Pay/PayIn checkout component, a white-labelable Connect widget, and a REST API (v1/v2, api-key + entity-id header auth) covering customers, entities, merchants, tokens, payments, payouts, and webhooks, plus out-of-the-box integrations with Stripe, Chargebee, and OpenPay. Backed by a16z. NOTE: Loop is winding down and folding into Lead; the service was sunset on 2026-02-13 and is not recommended for new integrations.

Loop Crypto publishes 1 API on the APIs.io network. Tagged areas include Company, Payments, Cryptocurrency, Stablecoins, and Web3.

The Loop Crypto catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Loop Crypto’s developer surface includes documentation, API reference, getting-started guide, signup flow, engineering blog, authentication, sandbox, and 12 more developer resources.

🌐 Visit website 📡 Source on GitHub

30.4/100 thin ▬ flat Agent 20/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

1 APIs

Company Payments Cryptocurrency Stablecoins Web3 Payment Processing Billing Solana Ethereum

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 30.4/100 · thin

Contract Quality 8.8 / 21

Developer Ergonomics 9.1 / 17

Access Clarity 1.1 / 17

Operational Transparency 2.0 / 11

Contract Governance 0.0 / 10

Discoverability 6.5 / 9

Regulatory Posture 2.8 / 15

Agent readiness — 20/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

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 0 / 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

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Payments regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/loop-crypto: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 1

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

Loop Crypto API

REST API for accepting crypto and stablecoin payments — customers, entities, merchants, tokens, payments, payouts, and webhooks. Authenticated with api-key and entity-id headers...

Event Specifications 1

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

Loop Crypto Webhooks

ASYNCAPI

Security Posture 2

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

Loop Crypto Authentication

apiKey · 2 schemes

SECURITY

Loop Crypto Domain Security

DNSSEC · DMARC

SECURITY

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal

GettingStarted

SignUp

Sandbox

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

Conventions

Webhooks

Lifecycle

Components

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

Packages

SDKs

CLI

Access & Security 2

Authentication, authorization, and security posture

Authentication

Authentication

DomainSecurity

DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Deprecation

Deprecation

Company 1

The organization behind the API

Blog

Blog

Source (apis.yml)

aid: loop-crypto
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: false
  label: Hosted service · you call their endpoint
  confidence: medium
  source:
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  - security
  - sandbox
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/loop-crypto.png
name: Loop Crypto
description: 'Loop Crypto is a crypto and stablecoin payment processor that lets merchants, billing software, and e-commerce
  platforms accept crypto and stablecoin payments end to end: charging a wallet, storing payment methods, accepting stablecoins,
  ERC-20 tokens, and Solana SPL tokens, and settling to merchants in either fiat or crypto. Loop offers payment links, an
  embeddable Pay/PayIn checkout component, a white-labelable Connect widget, and a REST API (v1/v2, api-key + entity-id header
  auth) covering customers, entities, merchants, tokens, payments, payouts, and webhooks, plus out-of-the-box integrations
  with Stripe, Chargebee, and OpenPay. Backed by a16z. NOTE: Loop is winding down and folding into Lead; the service was sunset
  on 2026-02-13 and is not recommended for new integrations.'
url: https://raw.githubusercontent.com/api-evangelist/loop-crypto/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- a16z
x-tier: stub
x-tier-reason: portfolio-lead
x-status: sunset
x-sunset-date: '2026-02-13'
x-successor: Lead
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Payments
- Cryptocurrency
- Stablecoins
- Web3
- Payment Processing
- Billing
- Solana
- Ethereum
apis:
- name: Loop Crypto API
  description: REST API for accepting crypto and stablecoin payments — customers, entities, merchants, tokens, payments, payouts,
    and webhooks. Authenticated with api-key and entity-id headers; URI-path versioned (v1, v2). A demo environment is available
    at demo.api.loopcrypto.xyz.
  humanURL: https://docs.loopcrypto.xyz
  baseURL: https://api.loopcrypto.xyz/api/v2/
  properties:
  - type: Documentation
    url: https://docs.loopcrypto.xyz
  - type: APIReference
    url: https://docs.loopcrypto.xyz/api/webhooks/list-webhooks
  - type: Authentication
    url: authentication/loop-crypto-authentication.yml
  - type: Webhooks
    url: asyncapi/loop-crypto-webhooks.yml
common:
- type: DeveloperPortal
  url: https://docs.loopcrypto.xyz
- type: Documentation
  url: https://docs.loopcrypto.xyz
- type: APIReference
  url: https://www.loopcrypto.xyz/api
- type: GettingStarted
  url: https://docs.loopcrypto.xyz/docs/get-set-up
- type: SignUp
  url: https://www.loopcrypto.xyz/get-started
- type: Blog
  url: https://www.loopcrypto.xyz/blog
- type: GitHubOrganization
  url: https://github.com/LoopCrypto
- type: Authentication
  url: authentication/loop-crypto-authentication.yml
- type: Conventions
  url: conventions/loop-crypto-conventions.yml
- type: Webhooks
  url: asyncapi/loop-crypto-webhooks.yml
- type: Lifecycle
  url: lifecycle/loop-crypto-lifecycle.yml
- type: Deprecation
  url: lifecycle/loop-crypto-lifecycle.yml
- type: Sandbox
  url: sandbox/loop-crypto-sandbox.yml
- type: Packages
  url: packages/loop-crypto-packages.yml
- type: SDKs
  url: packages/loop-crypto-packages.yml
- type: CLI
  url: cli/loop-crypto-cli.yml
- type: Components
  url: components/loop-crypto-components.yml
- type: DomainSecurity
  url: security/loop-crypto-domain-security.yml
- type: LLMsTxt
  url: llms/loop-crypto-llms.txt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
x-enrichment:
  date: '2026-07-20'
  status: enriched
  artifacts_added: 10
  pass: local-v1

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