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 is listed with 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 13 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

0.0/100 minimal ▬ flat Agent 0/100 human only saas Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

1 API

Company Payments Cryptocurrency Stablecoins Web3 Payment Processing Billing Solana Ethereum

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 0.0/100 · minimal

Contract Quality 0.0 / 21

Developer Ergonomics 0.0 / 17

Access Clarity 0.0 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.0 / 10

Discoverability 0.0 / 9

Regulatory Posture 1.6 / 15

Agent readiness — 0/100 · human only

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

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

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/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Rate-Limit Signaling +7 pts — OpenAPI responses document X-RateLimit-* / RateLimit headers (verified), else a rate_limits artifact or RateLimits link (documented)

10 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Contract Quality scores 0.0 — up to +25.0 composite points
Developer Ergonomics scores 0.0 — up to +20.0 composite points
Access Clarity scores 0.0 — up to +20.0 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

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 the provider profile at artifacts.apis.io/loop-crypto/apis.yml: open an issue on github.com/api-evangelist/loop-crypto to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
Stablecoins and Tokenization (stablecoin issuers, tokenized assets)	standard	17.2 (thin)	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

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 2

The organization behind the API

Website

Website

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: '2026-11-06'
  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: '2026-09-16'
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: Website
  url: https://loopcrypto.xyz
- 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
x-lifecycle:
  state: unresolved
  reason: domain-does-not-resolve
  observed: '2026-09-27'
  detail: The company's own domain returned no A or AAAA record when probed. This is an observation about the domain, not
    a request from the company.
  indexed: true
  successor: Lead
  successor_in_catalog: false

Loop Crypto API — frequently asked questions

Does Loop Crypto have an API?

Yes. APIs.io lists 1 API from Loop Crypto, including Loop Crypto API.

How do I authenticate with the Loop Crypto API?

Loop Crypto uses bearer-token authentication (apiKey · 2 schemes). The details are profiled on APIs.io as Loop Crypto Authentication.

Is the Loop Crypto API ready for AI agents?

Loop Crypto has a Kin Score of 0.0 out of 100 (minimal) and an Agent Readiness score of 0.0 (human-only), scored by API Evangelist on 2026-11-06.

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