> ## Documentation Index > Fetch the complete documentation index at: https://docs.markapidown.net/llms.txt > Use this file to discover all available pages before exploring further. # Executable Markdown API Docs > Reqbook stores API documentation as runnable markdown specs for developers, CI, local UI, and AI coding agents. # Agent-native across 6 coding tools, visual debugger, fast CLI, your entire API lives in plain markdown. Reqbook stores API work as plain markdown files. Send ad-hoc requests from the terminal or browser. Design API contracts. Validate them in CI. Your coding agent can read, write, and run everything. No hosted workspace, no proprietary format just files in your repo. Terminal interface: `rqb request`, `rqb exec`, `rqb flow`, and more. Browser interface: New Request panel, endpoint runner, flow canvas. MCP tools and skills for Claude Code, Cursor, Copilot, and others. Install Reqbook, create a project, and execute your first request in under five minutes. Install skills and MCP tools so Claude Code, Cursor, Copilot, and others can work with specs directly. Browse specs, tune parameters, send requests, inspect responses, and edit markdown all in the browser. Use Reqbook in your agent loop: document routes, run endpoints, build flows, and review changes. *** ## How it works Every API operation lives in a markdown file: ``` api-docs/ ├── reqbook.md # Project config and defaults ├── _shared/ │ ├── env.template.md # Shared environment template │ └── env.md # Local environment values ├── apis/ │ ├── users/ │ │ ├── get-user-by-id.md │ │ └── create-user.md │ └── orders/ │ └── post-orders.md └── flows/ └── checkout.md # Multi-step pipeline ``` The same files are used by: | Surface | What it does | | ------------ | ----------------------------------------------------------------------------------------- | | `rqb exec` | Sends the HTTP request and diffs the response | | `rqb serve` | Renders a browser UI for interactive testing | | `rqb mock` | Serves recorded responses without a live backend | | `rqb flow` | Runs a pipeline, captures values, injects them into later steps | | Agent skills | Teaches agents the format, file layout, and how to validate changes | | MCP tools | Lets compatible agents search, execute, author, and summarize specs without shell parsing | | CI | Validates all specs and exits non-zero on any failure | *** ## The vibe coding loop Ask your agent to document a route, import from curl, or scan the project for missing specs: ```text theme={null} Scan this project for API routes and add missing Reqbook specs. ``` ```text theme={null} Document POST /orders and make it runnable in Reqbook. ``` ```bash theme={null} rqb serve # → Preview: http://127.0.0.1:8080 ``` Inspect the generated markdown, adjust runtime params, run the request, and compare the response against the expected value. Ask the agent to connect specs into a pipeline: ```text theme={null} Create a checkout flow: create customer → create order, capture orderId → fetch order. ``` The flow is saved as `api-docs/flows/checkout.md` and runnable from both CLI and browser. ```bash theme={null} rqb validate api-docs/ ``` Specs are ordinary markdown. Every change is reviewable, diffable, and revertable in your PR. *** ## Without Reqbook, agents work blind When an agent needs to test an API endpoint without Reqbook, it reads router files, middleware, env config, constructs a `curl` command, parses raw stdout, and throws everything away. The next session starts from zero. | Task | Without Reqbook | With Reqbook | | ---------------------------- | ----------------------------------------------------------------- | ------------------------------------------------------------------------- | | Test one endpoint | Read source files, construct curl, parse stdout | `rqb_exec spec.md` structured result | | Diagnose an endpoint failure | Search logs and handlers manually | `rqb_diagnose spec.md` likely cause, inspect targets, and verify commands | | Debug multi-step flow | Write a temp script, manually chain requests, no trace on failure | `rqb_flow pipeline.md` per-step state, captured values | | Detect a regression | Only after a bug report | `rqb check` or `rqb validate` in CI fails before merge | | Agent discovers APIs | Scan broad source and docs manually | `rqb context` and `rqb_search` return bounded API context | | Share tests with team | "Send me the curl" | Commit markdown, review in PR | | Mock backend | Run live server or hardcode | `rqb mock` from recorded responses | The setup cost is five minutes (`rqb init`). After that, API docs, tests, CI checks, mock responses, and agent context come from the same reviewable markdown files. *** ## Why not Postman, Insomnia, Bruno, or Hurl? GUI tools store state in app databases or proprietary formats. Agents cannot read or write them reliably. Reqbook specs are plain markdown any agent can read, create, and edit them. Specs live in `api-docs/` alongside your code. Every API change goes through code review. No "export to share" step, no drift between the tool and the repo. The same file runs in the CLI, renders in the browser UI, serves the mock server, and validates in CI. You describe the API once. A single Rust binary. No signup, no workspace ID, no internet dependency at runtime. Works offline. Postman is the right choice when a team wants a broad hosted API platform with collaboration, monitoring, and governance. Bruno is the right choice when a team primarily wants a mature Git-native desktop API client. Hurl is the right choice when a team wants a fast plain-text HTTP test runner in CI. Reqbook is for teams that want API docs in the repo to be readable, executable, reviewable in PRs, runnable in CI, and directly usable by coding agents. *** ## Next steps Run a real API request in five minutes. Install skills, slash commands, and MCP for supported coding agents. Start `rqb serve` and explore the browser UI.