Monzo

Monzo is a UK-based digital challenger bank (Monzo Bank Ltd, FCA-authorised) offering current accounts, savings pots, joint accounts, business banking and lending through a mobile-first app. For developers, Monzo publishes a public REST API at api.monzo.com that lets a user build personal applications against their own Monzo account: listing accounts, reading balances, managing savings pots, retrieving and annotating transactions, uploading receipts and attachments, posting custom feed items into the app, and registering webhooks for real-time transaction notifications. Access uses OAuth 2.0 with Strong Customer Authentication (SCA) approved via push notification in the Monzo app. The API is intended for personal use and small groups of authorised users rather than large public applications.

Monzo publishes 1 API on the APIs.io network. Tagged areas include Company, Banking, Fintech, Financial-Services, and Payments.

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

Monzo’s developer surface includes authentication, sandbox, documentation, API reference, getting-started guide, engineering blog, support, and 21 more developer resources.

🌐 Visit website 📡 Source on GitHub

42.3/100 developing ▬ flat Agent 27/100 agent aware saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessSelf serve

1 APIs 1 MCP Servers

Company Banking Fintech Financial-Services Payments Open Banking Account Transaction Authentication

Kin Score

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

Composite quality — 42.3/100 · developing

Contract Quality 8.8 / 21

Developer Ergonomics 11.2 / 17

Access Clarity 3.6 / 17

Operational Transparency 4.4 / 11

Contract Governance 0.5 / 10

Discoverability 6.5 / 9

Regulatory Posture 5.9 / 15

Agent readiness — 27/100 · 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 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 0 / 7

Typed Event Surface 6 / 6

Agent Skills 5 / 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 Banking & Open Finance 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/monzo: 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.

Monzo API

The Monzo API is a REST interface over a user's Monzo account. It exposes accounts, balance, savings pots (with deposit/withdraw), transactions (list, retrieve, annotate with me...

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Monzo MCP (candidate)

MCP SERVER

Event Specifications 1

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

Monzo Webhooks

ASYNCAPI

Security Posture 3

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

Monzo Authentication

oauth2/http · 2 schemes

SECURITY

Monzo Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Monzo Vulnerability Disclosure

Intigriti · security.txt · contact published

SECURITY

Resources

Get Started 3

Portal, sign-up, and the first successful call

Sandbox

Sandbox

DeveloperPortal

DeveloperPortal

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

Documentation

Documentation

APIReference

APIReference

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

WellKnown

MCPServer

LLMsTxt

AgentSkill

Design & Contract 7

Pagination, idempotency, versioning, errors, and events

Conventions

Idempotency

ErrorCatalog

Lifecycle

Conformance

DataModel

Webhooks

Scroll for all 7

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 5

Authentication, authorization, and security posture

VulnerabilityDisclosure

VulnerabilityDisclosure

Security

DomainSecurity

SecurityTxt

Authentication

Operate 2

Status, limits, changes, and where to get help

Support

Support

StatusPage

StatusPage

Commercial 2

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

PrivacyPolicy

PrivacyPolicy

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: monzo
name: Monzo
description: 'Monzo is a UK-based digital challenger bank (Monzo Bank Ltd, FCA-authorised) offering current accounts, savings
  pots, joint accounts, business banking and lending through a mobile-first app. For developers, Monzo publishes a public
  REST API at api.monzo.com that lets a user build personal applications against their own Monzo account: listing accounts,
  reading balances, managing savings pots, retrieving and annotating transactions, uploading receipts and attachments, posting
  custom feed items into the app, and registering webhooks for real-time transaction notifications. Access uses OAuth 2.0
  with Strong Customer Authentication (SCA) approved via push notification in the Monzo app. The API is intended for personal
  use and small groups of authorised users rather than large public applications.'
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: 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://monzo.com/static/images/favicon.png
url: https://raw.githubusercontent.com/api-evangelist/monzo/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- general-catalyst
x-tier: profiled
x-tier-reason: enriched-from-portfolio-lead
x-enrichment:
  date: '2026-07-20'
  status: enriched
  artifacts_added: 16
  pass: local-v1
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-20'
tags:
- Company
- Banking
- Fintech
- Financial-Services
- Payments
- Open Banking
- Account
- Transaction
- Authentication
tags_raw:
- Company
- Banking
- Fintech
- Financial Services
- Payments
- Open Banking
- Accounts
- Transactions
- OAuth
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: VulnerabilityDisclosure
  url: security/monzo-vulnerability-disclosure.yml
- name: Monzo Security Policy & Bug Bounty
  url: https://monzo.com/.well-known/security.txt
  type: Security
- type: DomainSecurity
  url: security/monzo-domain-security.yml
- name: Monzo security.txt
  url: well-known/monzo-security.txt
  type: SecurityTxt
- name: Monzo Well-Known Index
  url: well-known/monzo-well-known.yml
  type: WellKnown
- name: Monzo Authentication Profile
  url: authentication/monzo-authentication.yml
  type: Authentication
- name: Monzo API Conventions
  url: conventions/monzo-conventions.yml
  type: Conventions
- name: Monzo Idempotency (dedupe_id)
  url: conventions/monzo-conventions.yml
  type: Idempotency
- name: Monzo Error Catalog
  url: errors/monzo-problem-types.yml
  type: ErrorCatalog
- name: Monzo Lifecycle
  url: lifecycle/monzo-lifecycle.yml
  type: Lifecycle
- name: Monzo Conformance
  url: conformance/monzo-conformance.yml
  type: Conformance
- name: Monzo Data Model
  url: data-model/monzo-data-model.yml
  type: DataModel
- name: Monzo API Playground
  url: sandbox/monzo-sandbox.yml
  type: Sandbox
- name: Monzo MCP (candidate)
  url: mcp/monzo-mcp.yml
  type: MCPServer
- name: Monzo llms.txt
  url: llms/monzo-llms.txt
  type: LLMsTxt
- name: Monzo Webhooks
  url: asyncapi/monzo-webhooks.yml
  type: Webhooks
- name: Monzo Agent Skills
  url: skills/_index.yml
  type: AgentSkill
- name: Monzo
  url: https://monzo.com
  type: Website
- name: Monzo for Developers
  url: https://developers.monzo.com
  type: DeveloperPortal
- name: Monzo API Documentation
  url: https://docs.monzo.com
  type: Documentation
- name: Monzo API Reference
  url: https://docs.monzo.com
  type: APIReference
- name: Monzo Developer Playground
  url: https://developers.monzo.com/api/playground
  type: GettingStarted
- name: Monzo Blog
  url: https://monzo.com/blog/
  type: Blog
- name: Monzo Community
  url: https://community.monzo.com
  type: Support
- name: Monzo on GitHub
  url: https://github.com/monzo
  type: GitHubOrganization
- name: Monzo Status
  url: https://status.monzo.com
  type: StatusPage
- name: Monzo Terms and Conditions
  url: https://monzo.com/legal/terms-and-conditions/
  type: TermsOfService
- name: Monzo Privacy Policy
  url: https://monzo.com/legal/privacy-policy/
  type: PrivacyPolicy
apis:
- aid: monzo:monzo-api
  name: Monzo API
  humanURL: https://docs.monzo.com
  baseURL: https://api.monzo.com
  tags:
  - Banking
  - Account
  - Balances
  - Pots
  - Transaction
  - Feed
  - Attachments
  - Receipts
  - Webhook
  tags_raw:
  - Banking
  - Accounts
  - Balance
  - Pots
  - Transactions
  - Feed
  - Attachments
  - Receipts
  - Webhooks
  properties:
  - url: https://docs.monzo.com
    type: Documentation
  - url: https://docs.monzo.com
    type: APIReference
  - url: https://developers.monzo.com/api/playground
    type: GettingStarted
  description: The Monzo API is a REST interface over a user's Monzo account. It exposes accounts, balance, savings pots (with
    deposit/withdraw), transactions (list, retrieve, annotate with metadata, expand merchant), feed items, attachments, transaction
    receipts, and webhooks for real-time transaction.created notifications. Authentication is OAuth 2.0 (authorization code
    grant) with Strong Customer Authentication approved in the Monzo mobile app; all requests carry a Bearer access token.

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