Fastify

Fastify is a fast and low-overhead web framework for Node.js, designed for building high-performance APIs and microservices. It features a powerful plugin architecture, JSON Schema-based request and response validation, automatic serialization, comprehensive logging with Pino, and TypeScript support out of the box.

Fastify is listed with 1 API on the APIs.io network. Tagged areas include Framework, High Performance, JavaScript, JSON Schema, and Node.js.

The Fastify catalog on APIs.io includes 1 Spectral governance ruleset.

Fastify’s developer surface includes documentation, getting-started guide, engineering blog, and 17 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

28.2/100 thin ▬ flat Agent 1/100 human only Front door AI 1/6 silent self hosted · MIT Full breakdown ↓
scored 2026-10-23 · rubric v0.25.0 · Show this score on your site →

AccessFreemium

1 API

Framework High Performance JavaScript JSON Schema Node.js TypeScript

Kin Score

Kin Score How this is scored →
scored 2026-10-23 · rubric v0.25.0

Composite quality — 28.2/100 · thin

Contract Quality 2.3 / 19

Developer Ergonomics 3.6 / 15

Access Clarity 1.2 / 15

Operational Transparency 3.6 / 10

Contract Governance 0.9 / 9

Discoverability 4.8 / 8

Regulatory Posture 0.9 / 15

Open Source Surface 10.0 / 10

Agent readiness — 1/100 · human only

Machine-Readable Contract 0 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 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 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

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) 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.

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against 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 75 points between them, because both conditional facets apply and carry 25 points together. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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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/fastify: 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 →

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
OpenSSF Best Practices Badge Holders	undeclared	-	-	-

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.

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

JSON Schema

tagged — the provider's own APIs.json carries the standard as a tag; implementation not verified

APIs 1

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

Fastify

Fastify is a fast and low-overhead web framework for Node.js, designed for building high-performance APIs and microservices. It features a powerful plugin architecture, JSON Sch...

Pricing Plans 1

Published pricing tiers and plan structures.

Fastify Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Fastify Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Fastify Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Fastify — jsonschema rules

5 rules · 3 warnings 2 info

SPECTRAL

JSON Schema 2

Standalone JSON Schema definitions for this provider's data models.

Fastify Plugin and Server Configuration

18 properties

JSON SCHEMA

Fastify Route Schema Definition

10 properties

JSON SCHEMA

Security Posture 1

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

Fastify Domain Security

TLSv1.3 · HSTS

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 2

Reference material describing how the API behaves

ContributionGuide

ContributionGuide

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

LlmsText

LlmsText

Build 4

SDKs, sample code, and the tooling you integrate with

CodeOfConduct

CodeOfConduct

GitHubOrganization

GitHubOrganization

GitHubRepository

GitHubRepository

Plugins

Plugins

Access & Security 2

Authentication, authorization, and security posture

SecurityPolicy

SecurityPolicy

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

RateLimits

RateLimits

IssueTracker

IssueTracker

Releases

Releases

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

License

License

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Other 1

Properties that don't map to a standard resource type

Benchmarks

Benchmarks

Source (apis.yml)

aid: fastify
name: Fastify
description: Fastify is a fast and low-overhead web framework for Node.js, designed for building high-performance APIs and
  microservices. It features a powerful plugin architecture, JSON Schema-based request and response validation, automatic
  serialization, comprehensive logging with Pino, and TypeScript support out of the box.
type: Index
deliveryModel:
  model: self-hosted
  license: MIT
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/fastify.png
tags:
- Framework
- High Performance
- JavaScript
- JSON Schema
- Node.js
- TypeScript
tags_raw:
- Frameworks
- High Performance
- JavaScript
- JSON Schema
- Node.js
- TypeScript
- JSON-Schema
url: https://raw.githubusercontent.com/api-evangelist/fastify/refs/heads/main/apis.yml
created: '2026-03-26'
modified: '2026-04-28'
specificationVersion: '0.23'
apis:
- aid: fastify:fastify
  name: Fastify
  description: Fastify is a fast and low-overhead web framework for Node.js, designed for building high-performance APIs and
    microservices. It features a powerful plugin architecture, JSON Schema-based request and response validation, automatic
    serialization, comprehensive logging with Pino, and TypeScript support out of the box.
  humanURL: https://fastify.dev/
  tags:
  - Framework
  - High Performance
  - JavaScript
  - JSON Schema
  - Node.js
  - TypeScript
  tags_raw:
  - Frameworks
  - High Performance
  - JavaScript
  - JSON Schema
  - Node.js
  - TypeScript
  - JSON-Schema
  properties:
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/fastify/refs/heads/main/json-schema/fastify-route-schema.json
  - type: JSONSchema
    url: https://raw.githubusercontent.com/api-evangelist/fastify/refs/heads/main/json-schema/fastify-plugin-config.json
common:
- type: Plans
  url: plans/fastify-plans-pricing.yml
- type: RateLimits
  url: rate-limits/fastify-rate-limits.yml
- type: FinOps
  url: finops/fastify-finops.yml
- type: IssueTracker
  url: https://github.com/fastify/fastify/issues
- type: Releases
  url: https://github.com/fastify/fastify/releases
- type: SecurityPolicy
  url: https://github.com/fastify/fastify/blob/main/SECURITY.md
- type: CodeOfConduct
  url: https://github.com/fastify/fastify/blob/main/CODE_OF_CONDUCT.md
- type: ContributionGuide
  url: https://github.com/fastify/fastify/blob/main/CONTRIBUTING.md
- type: License
  name: MIT
  url: https://github.com/fastify/fastify/blob/main/LICENSE
- type: DomainSecurity
  url: security/fastify-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/fastify-dev
- type: Website
  url: https://fastify.dev/
- type: Documentation
  url: https://fastify.dev/docs/latest/
- type: GettingStarted
  url: https://fastify.dev/docs/latest/Guides/Getting-Started/
- type: GitHubOrganization
  url: https://github.com/fastify
- type: GitHubRepository
  url: https://github.com/fastify/fastify
- type: Blog
  url: https://medium.com/@fastifyjs
- type: Plugins
  url: https://fastify.dev/ecosystem/
- type: Benchmarks
  url: https://fastify.dev/benchmarks/
- type: Integrations
  url: https://fastify.dev/ecosystem/
- type: LlmsText
  url: https://fastify.dev/llms.txt
integrations:
- name: Fastify Cheetah
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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