API development and debugging

Render OpenAPI 3.x and Swagger 2.0 specs in JSON or YAML as API docs with endpoints grouped by tag, parameters and schemas.

Developer utilities

Generate TypeScript types and an optional typed fetch client from an OpenAPI 3.0 or 3.1 spec in JSON or YAML, with $ref, allOf and oneOf support.

Converters

Diff two OpenAPI JSON specs and list added, removed and changed endpoints by method and path as a Markdown changelog.

Developer utilities

Build a GraphQL query or mutation from an operation name, dot-notation field paths and typed variables, with nested selections written for you.

Developer utilities

Parse a GraphQL SDL schema and browse its types, fields, arguments and references, with search and checks for undefined types.

Developer utilities

Build HTTP requests visually and generate code for cURL, fetch, axios, and Python with headers, auth, and query params

Developer utilities

Set a mock response's status, headers, JSON body and delay, then copy it as a fetch() mock, MSW handler, Express route, curl command or Python mock.

Developer utilities

Turn CSV into mock JSON API responses, an OpenAPI 3.1 spec, and Cloudflare Worker, Express or FastAPI endpoint code with pagination.

Developer utilities

Visually compose Mock Service Worker REST and GraphQL handlers with matchers, response shapes, delays, and one-shot semantics. Exports MSW v2 handlers.ts.

Generators

Convert cURL commands to JavaScript fetch, Axios, Python requests, Node.js http, PHP, and Go. Supports headers, JSON body, form data, and auth.

Converters

Diagnose a browser CORS error from its message and the response headers, and get the missing Access-Control headers plus an Express fix.

Developer utilities

Score pasted HTTP response headers on five security headers and summarize CORS and caching headers such as Access-Control-Allow-Origin and ETag.

Developer utilities

Look up HTTP status codes from 100 to 511 by number or keyword, with a description, details and typical use cases for each.

Developer utilities

Build a Set-Cookie header and matching document.cookie line with Secure, HttpOnly, SameSite, Path, Domain, Expires, Max-Age and Partitioned.

Developer utilities

Build an HTTP Cache-Control header from presets or individual directives, with a plain-language explanation and warnings for conflicting directives.

Generators

Convert an API rate limit and window into requests per second, and check expected traffic for utilization, headroom and an over-limit warning.

Developer utilities

Generate endpoint-level retry and idempotency contracts with deterministic test vectors and rollout guidance

Developer utilities

Analyze webhook payloads with formatted JSON view, HMAC signature verification, timestamp detection, and cURL reconstruction

Developer utilities

Verify a webhook's HMAC-SHA256 or HMAC-SHA1 signature against your signing secret, and inspect its headers, JSON body and timestamps.

Developer utilities

Connect to ws:// or wss:// endpoints with the native browser WebSocket API. Send and receive frames in JSON, text, or hex.

Developer utilities

Parse a Server-Sent Events log into event and data frames and replay the streamed text at 0.25x to 4x, with a timing chart and event-type counts.

Developer utilities

Decode an Anthropic Messages SSE stream into text, thinking and tool_use blocks, stop_reason and token usage including cache writes and reads.

AI tools

Build an OAuth 2.0 authorization code URL with a random state value, or a token exchange cURL command for the code you get back.

Developer utilities

Analyze a HAR file with a request waterfall, blocking time, third-party breakdown by host, slow requests, headers, total transfer size and wall time.

Developer utilities

Convert Drizzle ORM schemas to Prisma and back, with parity reports for tables, columns, relations, and indexes.

Converters