API-Fiddle

API-Fiddle is an interactive, collaborative API design platform for creating professional APIs based on OpenAPI. It provides first-class support for OpenAPI 3.x, data transfer objects, API versioning, suggested response codes, parameter serialization, pagination patterns, and response structuring best practices. API-Fiddle enables seamless sharing of API definitions with teams without requiring user accounts, making it accessible for collaboration throughout the API design lifecycle.

API-Fiddle publishes 5 APIs on the APIs.io network, including Export API, Projects API, Sharing API, and 2 more. Tagged areas include API Design, OpenAPI, Collaboration, Documentation, and Platform.

The API-Fiddle catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

API-Fiddle’s developer surface includes authentication, engineering blog, and 5 more developer resources.

🌐 Visit website 📡 Source on GitHub

32.4/100 thin ▬ flat Agent 20/100 agent aware Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemiumSelf serve⚡ Free to try

1 APIs 6 Features 3 Use Cases

API Design OpenAPI Collaboration Documentation Platform

Kin Score

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

Composite quality — 32.4/100 · thin

Contract Quality 15.8 / 23

Developer Ergonomics 2.6 / 18

Access Clarity 2.8 / 18

Operational Transparency 1.5 / 12

Contract Governance 1.1 / 11

Discoverability 6.0 / 9

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 20/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 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 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

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/api-fiddle: 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 5

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

API-Fiddle Export API

Export projects and specifications.

API-Fiddle Projects API

Manage API design projects.

API-Fiddle Sharing API

Share projects with other users.

API-Fiddle Specifications API

Manage API specifications within projects.

API-Fiddle Workspaces API

Organize projects into workspaces.

Open Collections 7

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

API Collection

OPEN COLLECTION

API-Fiddle API Fiddle API

OPEN COLLECTION

API-Fiddle API Fiddle Export API

OPEN COLLECTION

API-Fiddle API Fiddle Export Projects API

OPEN COLLECTION

API-Fiddle API Fiddle Export Sharing API

OPEN COLLECTION

API-Fiddle API Fiddle Export Specifications API

OPEN COLLECTION

API-Fiddle API Fiddle Export Workspaces API

OPEN COLLECTION

Scroll for all 7

Pricing Plans 1

Published pricing tiers and plan structures.

Api Fiddle Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Api Fiddle Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Api Fiddle Finops

FINOPS

Features 6

Notable capabilities this provider offers.

OpenAPI-First Design

Design professional REST APIs directly in the OpenAPI specification format with first-class support for OpenAPI 3.x standards.

Collaborative Playground

Share API definitions with teams without requiring user accounts, enabling frictionless collaboration across the API design process.

Data Transfer Object Support

First-class support for data transfer objects, enabling well-structured API schemas and reusable component definitions.

API Versioning

Built-in guidance and support for API versioning strategies to help teams manage API evolution over time.

Best Practice Guidance

Provides extensive guidance on parameter serialization, pagination patterns, response structuring, and suggested response codes.

Automation-Optimized

Specifications are optimized for automation and code generation, enabling integration into CI/CD pipelines and developer toolchains.

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Api Fiddle Context

13 classes · 6 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

API-Fiddle API Rules

5 rules · 3 warnings 2 info

SPECTRAL

JSON Schema 3

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

API Fiddle Project

9 properties

JSON SCHEMA

API Fiddle Specification

10 properties

JSON SCHEMA

API Fiddle Workspace

8 properties

JSON SCHEMA

Security Posture 2

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

Api Fiddle Authentication

http · 1 scheme

SECURITY

Api Fiddle Domain Security

TLSv1.3

SECURITY

Agentic Access 1

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

Api Fiddle Agentic Access

19 operations · 12 acting

AGENTIC

Use Cases 3

What developers build with this provider.

API Design and Prototyping

Design and prototype REST APIs using OpenAPI before implementation, enabling API-first development workflows.

Team Collaboration on API Specs

Collaborate with distributed teams on OpenAPI specifications without requiring accounts, reducing friction in the review process.

API Documentation

Generate and publish professional API documentation from OpenAPI specifications with integrated tooling.

Integrations 2

Pre-built integrations with other platforms and tools.

GitHub

GitHub App integration for connecting API Fiddle projects to GitHub repositories for version control and CI/CD workflows.

OpenAPI Ecosystem

Exports standard OpenAPI 3.x specifications compatible with the full OpenAPI tooling ecosystem including generators, validators, and documentation tools.

Resources

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

LlmsText

LlmsText

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubRepository

GitHubRepository

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Company 2

The organization behind the API

Website

Website

Blog

Blog

Source (apis.yml)

aid: api-fiddle
name: API-Fiddle
description: API-Fiddle is an interactive, collaborative API design platform for creating professional APIs based on OpenAPI.
  It provides first-class support for OpenAPI 3.x, data transfer objects, API versioning, suggested response codes, parameter
  serialization, pagination patterns, and response structuring best practices. API-Fiddle enables seamless sharing of API
  definitions with teams without requiring user accounts, making it accessible for collaboration throughout the API design
  lifecycle.
type: Index
deliveryModel:
  model: unknown
  open_source: unknown
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  - repository-unlicensed
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/api-fiddle.png
tags:
- API Design
- OpenAPI
- Collaboration
- Documentation
- Platform
url: https://raw.githubusercontent.com/api-evangelist/api-fiddle/refs/heads/main/apis.yml
created: '2025-01-08'
modified: '2026-05-19'
specificationVersion: '0.23'
apis:
- aid: api-fiddle:api-fiddle-export-api
  name: API-Fiddle Export API
  description: Export projects and specifications.
  humanURL: https://api-fiddle.com/
  tags:
  - Export
  properties:
  - type: OpenAPI
    url: openapi/api-fiddle-export-api-openapi.yml
  - type: Documentation
    url: https://api-fiddle.com/
  - type: JSONSchema
    url: json-schema/api-fiddle-project-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-specification-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-workspace-schema.json
  - type: JSONLD
    url: json-ld/api-fiddle-context.jsonld
- aid: api-fiddle:api-fiddle-projects-api
  name: API-Fiddle Projects API
  description: Manage API design projects.
  humanURL: https://api-fiddle.com/
  tags:
  - Project
  tags_raw:
  - Projects
  properties:
  - type: OpenAPI
    url: openapi/api-fiddle-projects-api-openapi.yml
  - type: Documentation
    url: https://api-fiddle.com/
  - type: JSONSchema
    url: json-schema/api-fiddle-project-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-specification-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-workspace-schema.json
  - type: JSONLD
    url: json-ld/api-fiddle-context.jsonld
- aid: api-fiddle:api-fiddle-sharing-api
  name: API-Fiddle Sharing API
  description: Share projects with other users.
  humanURL: https://api-fiddle.com/
  tags:
  - Sharing
  properties:
  - type: OpenAPI
    url: openapi/api-fiddle-sharing-api-openapi.yml
  - type: Documentation
    url: https://api-fiddle.com/
  - type: JSONSchema
    url: json-schema/api-fiddle-project-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-specification-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-workspace-schema.json
  - type: JSONLD
    url: json-ld/api-fiddle-context.jsonld
- aid: api-fiddle:api-fiddle-specifications-api
  name: API-Fiddle Specifications API
  description: Manage API specifications within projects.
  humanURL: https://api-fiddle.com/
  tags:
  - Specifications
  properties:
  - type: OpenAPI
    url: openapi/api-fiddle-specifications-api-openapi.yml
  - type: Documentation
    url: https://api-fiddle.com/
  - type: JSONSchema
    url: json-schema/api-fiddle-project-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-specification-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-workspace-schema.json
  - type: JSONLD
    url: json-ld/api-fiddle-context.jsonld
- aid: api-fiddle:api-fiddle-workspaces-api
  name: API-Fiddle Workspaces API
  description: Organize projects into workspaces.
  humanURL: https://api-fiddle.com/
  tags:
  - Workspaces
  properties:
  - type: OpenAPI
    url: openapi/api-fiddle-workspaces-api-openapi.yml
  - type: Documentation
    url: https://api-fiddle.com/
  - type: JSONSchema
    url: json-schema/api-fiddle-project-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-specification-schema.json
  - type: JSONSchema
    url: json-schema/api-fiddle-workspace-schema.json
  - type: JSONLD
    url: json-ld/api-fiddle-context.jsonld
common:
- type: AgenticAccess
  url: agentic-access/api-fiddle-agentic-access.yml
- type: DomainSecurity
  url: security/api-fiddle-domain-security.yml
- type: Authentication
  url: authentication/api-fiddle-authentication.yml
- type: Website
  url: https://api-fiddle.com/
- type: Blog
  url: https://blog.api-fiddle.com/
- type: GitHubRepository
  url: https://github.com/apps/api-fiddle
- type: Features
  data:
  - name: OpenAPI-First Design
    description: Design professional REST APIs directly in the OpenAPI specification format with first-class support for OpenAPI
      3.x standards.
  - name: Collaborative Playground
    description: Share API definitions with teams without requiring user accounts, enabling frictionless collaboration across
      the API design process.
  - name: Data Transfer Object Support
    description: First-class support for data transfer objects, enabling well-structured API schemas and reusable component
      definitions.
  - name: API Versioning
    description: Built-in guidance and support for API versioning strategies to help teams manage API evolution over time.
  - name: Best Practice Guidance
    description: Provides extensive guidance on parameter serialization, pagination patterns, response structuring, and suggested
      response codes.
  - name: Automation-Optimized
    description: Specifications are optimized for automation and code generation, enabling integration into CI/CD pipelines
      and developer toolchains.
- type: UseCases
  data:
  - name: API Design and Prototyping
    description: Design and prototype REST APIs using OpenAPI before implementation, enabling API-first development workflows.
  - name: Team Collaboration on API Specs
    description: Collaborate with distributed teams on OpenAPI specifications without requiring accounts, reducing friction
      in the review process.
  - name: API Documentation
    description: Generate and publish professional API documentation from OpenAPI specifications with integrated tooling.
- type: Integrations
  data:
  - name: GitHub
    description: GitHub App integration for connecting API Fiddle projects to GitHub repositories for version control and
      CI/CD workflows.
  - name: OpenAPI Ecosystem
    description: Exports standard OpenAPI 3.x specifications compatible with the full OpenAPI tooling ecosystem including
      generators, validators, and documentation tools.
- type: LlmsText
  url: https://api-fiddle.com/llms.txt
maintainers:
- FN: Kin Lane
  email: info@apievangelist.com

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