Design & Build
Go from an idea — or a file — to a documented API.
Builder
LiveGenerate a documented API from a CSV, JSON, YAML or spreadsheet file — in your browser, free.
Spec Hub
PlannedManage OpenAPI specifications in one place, versioned and validated.
Workspaces
PlannedCollaborate with your team on APIs, specs and collections.
Mock Servers
PlannedSimulate API behavior from a spec before a line of backend exists.
SDK Generator
PlannedCreate client SDKs in popular languages instantly from your spec.
Flows
PlannedCompose visual workflows that chain requests together.
Test & Validate
Send requests, automate checks, and keep APIs healthy.
API Explorer
LiveBrowse and send GET requests to any GratisAPI endpoint and see the live JSON.
API Reference
LiveInteractive Swagger UI with “Try it out” on every endpoint, from a full OpenAPI 3.1 spec.
Dynamic API
Deploy-readyFilter, search, sort, paginate and randomize any dataset — a tested Cloudflare Worker over the static data. Code's in the repo; awaiting a deploy token.
Collection Runner
PlannedAutomate multi-request API workflows and assertions.
Monitors
PlannedSchedule checks that validate uptime and performance.
Webhooks
PlannedFirst-class webhook capture, inspection and replay.
Manage & Operate
Know every API you have, and put AI to work on them.
API Catalog
LiveA machine-readable directory of every API and every record, at /api/index.
Insights
PlannedTrack usage across every endpoint over time.
AI Engineer
PlannedAn assistant that helps you design, document and debug your APIs.
Agent Mode
PlannedAutomate API workflows end to end with native AI.
GratisAPI CLI
PlannedWork with your APIs from the command line and CI.
MCP Server
PlannedGive API context to your AI agents over the Model Context Protocol.
On the horizon
Bigger bets we're exploring.
API Gateway
ExploringRoute, govern and observe API (and AI) traffic at the edge.
Docs & SDKs
ExploringInstantly generate polished API docs and typed SDKs.
Agent Control
ExploringManage and control AI agents that consume your APIs in production.
Free and libre, the whole way
Every tool here will follow the same rules as the rest of GratisAPI: no keys, no lock-in, open source under the GPL. Want something on this list sooner? Open an issue or contribute on GitHub.