FreeAgent

FreeAgent is UK-focused cloud accounting software for small businesses, freelancers, and accountants, providing invoicing, expense tracking, time tracking, project management, banking, payroll, and Self Assessment / VAT filing through HMRC's Making Tax Digital. The FreeAgent API is a RESTful service that exposes contacts, invoices, estimates, expenses, bills, timeslips, projects, bank accounts, bank transactions, transaction explanations, and tax timeline events for company accounts and accountancy practices. Authentication uses OAuth 2.0 (authorization code flow) and responses are available in JSON or XML.

FreeAgent publishes 4 APIs on the APIs.io network, including REST API, BankAccounts API, Contacts API, and 1 more. Tagged areas include Accounting, Small Business, Invoicing, Bookkeeping, and Expenses.

FreeAgent’s developer surface includes authentication, documentation, pricing, signup flow, support, engineering blog, and 8 more developer resources.

🌐 Visit website 📡 Source on GitHub

38.1/100 thin ▬ flat Agent 24/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessSelf serve

1 APIs

Accounting Small Business Invoicing Bookkeeping Expenses Payroll VATHMRCMaking Tax Digital

Kin Score

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

Composite quality — 38.1/100 · thin

Contract Quality 11.5 / 23

Developer Ergonomics 11.1 / 18

Access Clarity 4.3 / 18

Operational Transparency 1.8 / 12

Contract Governance 0.0 / 11

Discoverability 6.2 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 24/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 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 0 / 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 6 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

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/freeagent: 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 4

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

FreeAgent REST API

RESTful API for the FreeAgent cloud accounting platform. Provides full access to invoices, estimates, contacts, bills, expenses, projects, timeslips, bank accounts, transactions...

FreeAgent BankAccounts API

The BankAccounts API from FreeAgent — 2 operation(s) for bankaccounts.

FreeAgent Contacts API

The Contacts API from FreeAgent — 2 operation(s) for contacts.

FreeAgent Invoices API

The Invoices API from FreeAgent — 10 operation(s) for invoices.

Open Collections 5

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

API Collection

OPEN COLLECTION

FreeAgent BankAccounts API

OPEN COLLECTION

FreeAgent BankAccounts Contacts API

OPEN COLLECTION

FreeAgent BankAccounts Invoices API

OPEN COLLECTION

FreeAgent API

OPEN COLLECTION

Security Posture 3

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

Freeagent Authentication

oauth2 · 1 scheme

SECURITY

Freeagent Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Freeagent Vulnerability Disclosure

security.txt · contact published

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Freeagent Scopes

OAuth 2.0 · no documented scopes

0 scopes

SCOPES

Agentic Access 1

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

Freeagent Agentic Access

23 operations · 15 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

DeveloperPortal

DeveloperPortal

Signup

Signup

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Access & Security 4

Authentication, authorization, and security posture

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Authentication

Authentication

OAuthScopes

OAuthScopes

Operate 2

Status, limits, changes, and where to get help

Support

Support

StatusPage

StatusPage

Commercial 1

Pricing, plans, and the legal terms of use

Pricing

Pricing

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Source (apis.yml)

aid: freeagent
name: FreeAgent
description: FreeAgent is UK-focused cloud accounting software for small businesses, freelancers, and accountants, providing
  invoicing, expense tracking, time tracking, project management, banking, payroll, and Self Assessment / VAT filing through
  HMRC's Making Tax Digital. The FreeAgent API is a RESTful service that exposes contacts, invoices, estimates, expenses,
  bills, timeslips, projects, bank accounts, bank transactions, transaction explanations, and tax timeline events for company
  accounts and accountancy practices. Authentication uses OAuth 2.0 (authorization code flow) and responses are available
  in JSON or XML.
type: Index
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: medium
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/freeagent.png
tags:
- Accounting
- Small Business
- Invoicing
- Bookkeeping
- Expenses
- Payroll
- VAT
- HMRC
- Making Tax Digital
url: https://raw.githubusercontent.com/api-evangelist/freeagent/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-11'
specificationVersion: '0.23'
apis:
- aid: freeagent:rest-api
  name: FreeAgent REST API
  description: RESTful API for the FreeAgent cloud accounting platform. Provides full access to invoices, estimates, contacts,
    bills, expenses, projects, timeslips, bank accounts, transactions, and accountancy-practice resources. Authentication
    is OAuth 2.0 authorization code flow; a sandbox is available at api.sandbox.freeagent.com.
  humanURL: https://dev.freeagent.com/docs
  baseURL: https://api.freeagent.com/v2
  tags:
  - Accounting
  - Invoicing
  - Bookkeeping
  - Expenses
  - Bank Feeds
  - Authentication
  tags_raw:
  - Accounting
  - Invoicing
  - Bookkeeping
  - Expenses
  - Bank Feeds
  - OAuth 2.0
  properties:
  - type: Documentation
    url: https://dev.freeagent.com/docs
  - type: Authentication
    url: https://dev.freeagent.com/docs/oauth
  - type: GettingStarted
    url: https://dev.freeagent.com/docs/quick_start
  - type: Sandbox
    url: https://api.sandbox.freeagent.com
  - type: PostmanCollection
    url: https://github.com/fac/postman-freeagent-api-collection
- aid: freeagent:freeagent-bankaccounts-api
  name: FreeAgent BankAccounts API
  description: The BankAccounts API from FreeAgent — 2 operation(s) for bankaccounts.
  humanURL: https://dev.freeagent.com/docs
  baseURL: https://api.freeagent.com/v2
  tags:
  - Bank Accounts
  tags_raw:
  - BankAccounts
  properties:
  - type: OpenAPI
    url: openapi/freeagent-bankaccounts-api-openapi.yml
- aid: freeagent:freeagent-contacts-api
  name: FreeAgent Contacts API
  description: The Contacts API from FreeAgent — 2 operation(s) for contacts.
  humanURL: https://dev.freeagent.com/docs
  baseURL: https://api.freeagent.com/v2
  tags:
  - Contacts
  properties:
  - type: OpenAPI
    url: openapi/freeagent-contacts-api-openapi.yml
- aid: freeagent:freeagent-invoices-api
  name: FreeAgent Invoices API
  description: The Invoices API from FreeAgent — 10 operation(s) for invoices.
  humanURL: https://dev.freeagent.com/docs
  baseURL: https://api.freeagent.com/v2
  tags:
  - Invoices
  properties:
  - type: OpenAPI
    url: openapi/freeagent-invoices-api-openapi.yml
common:
- type: AgenticAccess
  url: agentic-access/freeagent-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/freeagent-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/freeagent-domain-security.yml
- type: Authentication
  url: authentication/freeagent-authentication.yml
- type: OAuthScopes
  url: scopes/freeagent-scopes.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/freeagent
- type: Website
  url: https://www.freeagent.com
- type: Documentation
  url: https://dev.freeagent.com/docs
- type: DeveloperPortal
  url: https://dev.freeagent.com
- type: Pricing
  url: https://www.freeagent.com/pricing/
- type: Signup
  url: https://signup.freeagent.com/
- type: Support
  url: https://support.freeagent.com
- type: StatusPage
  url: https://status.freeagent.com
- url: https://www.freeagent.com/feed.rss
  type: Blog
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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