Finix Payments

Finix is a full-stack payments technology provider that lets businesses, software platforms, and marketplaces accept and send payments online and in person. Its REST API (version 2022-02-01) covers the full payments lifecycle — Identities, Merchants, Payment Instruments, Authorizations, Transfers, Settlements, Disputes, Verifications, Fee/Payout Profiles, Devices/terminals, and Webhooks — enabling card, ACH, EFT, digital-wallet, and Buy-Now-Pay-Later acceptance, seller onboarding/underwriting, split transfers, payouts, and payment facilitation (PayFac-as-a-service). Finix is a Level 1 PCI DSS certified platform with browser (finix.js) and mobile tokenization SDKs, hosted checkout pages, and payment links. Authentication is HTTP Basic Auth with environment-scoped API keys; the API uses cursor pagination, idempotency_id request-level idempotency, HAL responses, and dated versioning via the Finix-Version header.

Finix Payments publishes 1 API on the APIs.io network: Finix API. Tagged areas include Company, Payments, Payment Processing, Payment Facilitation, and Embedded Finance.

The Finix Payments catalog on APIs.io includes 1 event-driven AsyncAPI specification.

Finix Payments’ developer surface includes documentation, API reference, getting-started guide, support, engineering blog, pricing, signup flow, and 30 more developer resources.

🌐 Visit website 📡 Source on GitHub
55.7/100 developing Agent 87/100 agent native Full breakdown ↓
scored 2026-07-20 · rubric v0.4
1 APIs 1 MCP Servers 0 Features
CompanyPaymentsPayment ProcessingPayment FacilitationEmbedded FinanceMarketplacesACHCard AcceptanceFintechPCI DSS

API Rating

API Evangelist API Evangelist Rating How this is scored →
scored 2026-07-20 · rubric v0.4
Composite quality — 55.7/100 · developing
Contract Quality 13.1 / 25
Developer Ergonomics 16.1 / 20
Commercial Clarity 10.5 / 20
Operational Transparency 6.8 / 13
Governance 0.0 / 12
Discoverability 9.3 / 10
Agent readiness — 87/100 · agent native
Machine-Readable Contract 18 / 18
Agentic Access Contract 15 / 15
MCP Server 12 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 6 / 6
Agent Skills 5 / 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/finix-payments: 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

Finix API

The Finix payments REST API — accept and send card, ACH, EFT, and wallet payments; onboard and verify merchants; manage authorizations, transfers, settlements, disputes, and pay...

MCP Servers

finix-payments-mcp.yml

MCP SERVER

Arazzo Workflows

_Index

ARAZZO

Finix — Accept a card payment (auth + capture)

Create a buyer Identity, tokenize a card, authorize, then capture into a Transfer.

ARAZZO

Finix — Onboard a seller/merchant

Create a seller Identity, provision a Merchant, and run verification/underwriting.

ARAZZO

Rate Limits

Finix Payments Rate Limits

0 limits

RATE LIMITS

Event Specifications

Finix Payments Webhooks

ASYNCAPI

Resources

Get Started 4

Portal, sign-up, and the first successful call

DeveloperPortal
DeveloperPortal
 GettingStarted
GettingStarted
 SignUp
SignUp
 Sandbox
Sandbox

Documentation 2

Reference material describing how the API behaves

Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

MCPServer
MCPServer
 AgentSkill
AgentSkill
 AgenticAccess
AgenticAccess
 LLMsTxt
LLMsTxt

Design & Contract 10

Pagination, idempotency, versioning, errors, and events

Conventions
Conventions
 Idempotency
Idempotency
 ErrorCatalog
ErrorCatalog
 Lifecycle
Lifecycle
 Components
Components
 DataModel
DataModel
 Conformance
Conformance
 Webhooks
Webhooks
 Arazzo
Arazzo
 Arazzo
Arazzo

Scroll for all 10

Build 4

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization
 Packages
Packages
 SDKs
SDKs
 DeclineCodes
DeclineCodes

Access & Security 3

Authentication, authorization, and security posture

Authentication
Authentication
 Compliance
Compliance
 DomainSecurity
DomainSecurity

Operate 5

Status, limits, changes, and where to get help

Support
Support
 StatusPage
StatusPage
 RateLimits
RateLimits
 Deprecation
Deprecation
 ChangeLog
ChangeLog

Commercial 3

Pricing, plans, and the legal terms of use

Pricing
Pricing
 TermsOfService
TermsOfService
 PrivacyPolicy
PrivacyPolicy

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Source (apis.yml)

apis.yml Raw ↑ 
aid: finix-payments
name: Finix Payments
description: Finix is a full-stack payments technology provider that lets businesses, software platforms, and marketplaces
  accept and send payments online and in person. Its REST API (version 2022-02-01) covers the full payments lifecycle — Identities,
  Merchants, Payment Instruments, Authorizations, Transfers, Settlements, Disputes, Verifications, Fee/Payout Profiles, Devices/terminals,
  and Webhooks — enabling card, ACH, EFT, digital-wallet, and Buy-Now-Pay-Later acceptance, seller onboarding/underwriting,
  split transfers, payouts, and payment facilitation (PayFac-as-a-service). Finix is a Level 1 PCI DSS certified platform
  with browser (finix.js) and mobile tokenization SDKs, hosted checkout pages, and payment links. Authentication is HTTP Basic
  Auth with environment-scoped API keys; the API uses cursor pagination, idempotency_id request-level idempotency, HAL responses,
  and dated versioning via the Finix-Version header.
url: https://raw.githubusercontent.com/api-evangelist/finix-payments/refs/heads/main/apis.yml
image: https://images.ctfassets.net/kqru4vgwujx6/3dBfyfPS31FWqFPTwf4dRv/417cc8b5e94029726cffb9aa85230111/OG_Image.png?w=1200&q=90
x-type: company
x-source: vc-portfolio
x-backed-by:
- insight-partners
x-tier: enriched
x-tier-reason: openapi-and-docs-harvested
specificationVersion: '0.20'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Payments
- Payment Processing
- Payment Facilitation
- Embedded Finance
- Marketplaces
- ACH
- Card Acceptance
- Fintech
- PCI DSS
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
apis:
- name: Finix API
  description: The Finix payments REST API — accept and send card, ACH, EFT, and wallet payments; onboard and verify merchants;
    manage authorizations, transfers, settlements, disputes, and payouts. Version 2022-02-01, 91 operations, HTTP Basic Auth.
  humanURL: https://finix.com/docs/api
  baseURL: https://finix.live-payments-api.com
  properties:
  - type: OpenAPI
    url: openapi/finix-payments-openapi-original.yml
  - type: Overlay
    url: overlays/finix-payments-openapi-overlay.yaml
common:
- type: Website
  url: https://www.finixpayments.com/
- type: DeveloperPortal
  url: https://docs.finix.com/
- type: Documentation
  url: https://docs.finix.com/
- type: APIReference
  url: https://finix.com/docs/api
- type: GettingStarted
  url: https://docs.finix.com/guides/getting-started
- type: Support
  url: https://docs.finix.com/guides/getting-started/support-at-finix
- type: Blog
  url: https://finix.com/resources/blogs
- type: GitHubOrganization
  url: https://github.com/finix-payments
- type: Pricing
  url: https://finix.com/pricing
- type: SignUp
  url: https://dashboard.finixpayments.com
- type: TermsOfService
  url: https://finix.com/terms-and-policies
- type: PrivacyPolicy
  url: https://finix.com/terms-and-policies
- type: StatusPage
  url: https://status.finix.com
- type: Packages
  url: packages/finix-payments-packages.yml
- type: SDKs
  url: packages/finix-payments-packages.yml
- type: Authentication
  url: authentication/finix-payments-authentication.yml
- type: Conventions
  url: conventions/finix-payments-conventions.yml
- type: Idempotency
  url: conventions/finix-payments-conventions.yml
- type: RateLimits
  url: rate-limits/finix-payments-rate-limits.yml
- type: ErrorCatalog
  url: errors/finix-payments-problem-types.yml
- type: DeclineCodes
  url: errors/finix-payments-decline-codes.yml
- type: Lifecycle
  url: lifecycle/finix-payments-lifecycle.yml
- type: Deprecation
  url: https://docs.finix.com/additional-resources/developers/authentication-and-api-basics/versioning
- type: ChangeLog
  url: changelog/finix-payments-changelog.yml
- type: Sandbox
  url: sandbox/finix-payments-sandbox.yml
- type: Components
  url: components/finix-payments-components.yml
- type: DataModel
  url: data-model/finix-payments-data-model.yml
- type: Conformance
  url: conformance/finix-payments-conformance.yml
- type: Compliance
  url: conformance/finix-payments-conformance.yml
- type: Webhooks
  url: asyncapi/finix-payments-webhooks.yml
- type: MCPServer
  url: mcp/finix-payments-mcp.yml
- type: AgentSkill
  url: skills/_index.yml
- type: AgenticAccess
  url: agentic-access/finix-payments-agentic-access.yml
- type: LLMsTxt
  url: llms/finix-payments-llms.txt
- type: DomainSecurity
  url: security/finix-payments-domain-security.yml
- type: Arazzo
  name: Accept a card payment (auth + capture)
  url: arazzo/finix-payments-accept-a-card-payment.yml
- type: Arazzo
  name: Onboard a seller/merchant
  url: arazzo/finix-payments-onboard-a-merchant.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence