GOV.UK Notify
GOV.UK Notify is a UK government notification service operated by the Government Digital Service (GDS) that enables central government, local authorities, NHS organisations, and other eligible public bodies to send emails, text messages, and letters to citizens on behalf of government services. The platform provides a REST API, a web-based sending interface, and official client libraries for Python, Java, .NET, Node.js, PHP, and Ruby. Emails are free and unlimited; SMS messages include an annual free allowance by organisation type with per-message overage at 2.4p; physical letters are priced by postage class and page count with print and postage included. The API uses JWT-based authentication, supports template-driven personalisation, and enforces a throughput limit of 3,000 messages per minute per API key type.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles GOV.UK Notify the way a machine reads it — 23 machine-readable artifacts across 9 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — GOV.UK Notify scores 48.4/100 (developing), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
How we profile GOV.UK Notify
Each block below is one kind of artifact we hold for GOV.UK Notify. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 9
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
GOV.UK Notify Python Client
Official Python client library for the GOV.UK Notify API. Wraps the REST API with idiomatic Python methods for sending SMS, email, and letter notifications; retrieving notificat...
GOV.UK Notify Java Client
Official Java client library for the GOV.UK Notify API, providing methods for sending emails, SMS messages, and letters, as well as retrieving notification statuses and managing...
GOV.UK Notify .NET Client
Official .NET client library for the GOV.UK Notify API supporting C# and other .NET languages for sending government notifications via email, SMS, and letters.
GOV.UK Notify Node.js Client
Official Node.js client library for the GOV.UK Notify API for sending government notifications via email, SMS, and letters from JavaScript and TypeScript applications.
GOV.UK Notify PHP Client
Official PHP client library for the GOV.UK Notify API for sending government notifications via email, SMS, and letters from PHP applications.
GOV.UK Notify Ruby Client
Official Ruby client library for the GOV.UK Notify API for sending government notifications via email, SMS, and letters from Ruby and Ruby on Rails applications.
GOV.UK Notify Notifications API
Send and retrieve notifications (email, SMS, letters)
GOV.UK Notify Received Text Messages API
Retrieve inbound text messages
GOV.UK Notify Templates API
Retrieve and preview notification templates
Scroll within the panel for all 9 ·
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Plans
PLANSRate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Finops
FINOPSSpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
GOV.UK Notify API Rules
SPECTRALJSON Schema 3
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
Examples 3
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Security Posture 3
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for GOV.UK Notify — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 3
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Commercial 3
Pricing, plans, and the legal terms of use
Company 2
The organization behind the API
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