---
sidebar_position: 1
title: "Hen: API Testing Framework and Collection Runner"
description: "Test APIs, run request collections, and keep assertions, captures, and dependencies in one .hen file for local workflows, CI, and VS Code."
slug: /
---
# Hen
Hen is an API testing framework and collection runner. Define requests, assertions,
captures, and dependencies in a `.hen` file, then run the same collection in the terminal,
in CI, and in editor-assisted workflows.
## Why teams reach for Hen
- Keep requests, assertions, captures, and dependencies together in plain text.
- Verify collections structurally before any network calls or shell callbacks run.
- Reuse the same collection for local exploration, automation, and version-controlled collaboration.
- Author HTTP, GraphQL, SSE, and WebSocket flows in one format.
- Import OpenAPI 3.x specs into editable `.hen` starter collections instead of rewriting contracts by hand.
## A single file can express the workflow
```hen
name = Create export and wait
$ API_ORIGIN = https://api.example.com
$ API_TOKEN = secret.env("HEN_API_TOKEN")
---
Create export
POST {{ API_ORIGIN }}/exports
* Authorization = Bearer {{ API_TOKEN }}
^ & status == 202
& body.jobId -> $JOB_ID
---
Wait for export
> requires: Create export
GET {{ API_ORIGIN }}/exports/{{ JOB_ID }}
poll_until = 2m
poll_every = 2s
^ & status == 200
^ & body.state == "completed"
```
The same collection can now be:
- run interactively from the terminal
- executed non-interactively in CI
- inspected by editor tooling
Hen can also generate that starting collection from an OpenAPI contract:
```bash
hen import ./openapi.yaml --output ./api.hen
```
## What Hen is good at
- Replacing ad hoc curl scripts with reusable workflows
- Turning exploratory request collections into CI checks
- Keeping assertions close to the requests they validate
- Reusing captured values, cookies, prompts, and environments across related requests
- Giving editor tooling a machine-readable view of the same collection
## Choose your path
| If you want to... | Start here |
| --- | --- |
| Try Hen from the terminal | [Getting Started](./getting-started/index.md) |
| Start from an OpenAPI spec | [CLI Guide](./cli/index.md#openapi-import) |
| Learn the authoring syntax quickly | [Syntax Cheatsheet](./getting-started/syntax-cheatsheet.md) |
| Learn the day-to-day commands | [CLI Guide](./cli/index.md) |
| Look up flags and command syntax | [CLI Reference](./cli/reference.md) |
| Run collections in scripts or CI | [CI and Automation](./getting-started/ci-and-automation.md) |
| Copy a working pattern | [Recipes](./recipes/index.md) |
| Look up exact syntax | [Reference](./reference/index.md) |
## Core mental model
- A `.hen` file is executable API workflow source code.
- Variables and prompts define reusable inputs.
- Assertions validate each request inline.
- Captures and sessions let later requests build on earlier ones.
- `run`, `verify`, and `inspect` are different ways to use the same collection.
## Where Hen fits
Hen sits between raw HTTP tooling and heavyweight API platforms:
- more reusable than one-off shell commands
- more automation-friendly than GUI-only request tools
- more structured than stitching together ad hoc scripts
- easier to expose to editors and agents than homegrown request runners
## Canonical sources
The repository root `README.md` and `syntax-reference.md` remain the canonical long-form sources.
The website reorganizes that material into task-oriented pages for day-to-day use.