autocurl vs curl

curl is one of the most useful tools ever written, and autocurl does not try to replace it. autocurl solves a narrower problem: keeping the API requests for your own backend organised, readable, and easy to run again, for you and for AI coding agents.

Despite the name, autocurl does not call the curl binary. It has its own built-in Go HTTP client.

Summary

	autocurl	curl
Purpose	Generate, save, and run requests for your backend	General-purpose data transfer from the command line
Where requests come from	Generated from route declarations in your code	Typed by hand
Where requests live	A plain-text .autocurl file in your repo	Shell history, scripts, or notes
Running a request	Pick it by number	Retype or recall the full command
JSON bodies	Written as-is in the file, no shell escaping	Must be quoted and escaped for the shell
Variables	{{id}} placeholders, prompted or defined in the file	Shell variables
Response output	Status, duration, formatted JSON	Raw body (plus headers with -i)
Protocols and options	HTTP requests	Dozens of protocols and hundreds of options
Installed by default	No	On most systems

The same request, both ways

With curl, a POST with a JSON body and a path variable looks like this:

curl -s -X PUT "http://localhost:3000/users/42" \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -d '{"name": "Ada", "role": "admin"}'

With autocurl, the request is a block in a file:

@baseUrl = http://localhost:3000

### 3. PUT /users/{id}
# @source src/routes/users.js:52
PUT {{baseUrl}}/users/{{id}}
Content-Type: application/json
Accept: application/json

{"name": "Ada", "role": "admin"}

and running it is:

autocurl index.autocurl
# Select request: 3
# Enter value for id: 42

The JSON is written exactly as it is sent, with no shell quoting. The request is saved, numbered, and points back to the code that defines the route.

Why it matters for AI agents

When an AI coding agent tests an endpoint with curl, it has to guess the route, construct the command, and get the quoting right every time. With autocurl, the agent reads requests generated from the real routes and runs one with a single command such as printf '3\n42\n' | autocurl index.autocurl. See using autocurl with AI coding agents.

When to use plain curl

Stick with curl when:

• you need a quick one-off request against any URL
• you rely on curl's options, such as client certificates, proxies, cookies, or protocols beyond HTTP
• you are writing shell scripts that must run anywhere without extra tools
• you need precise control over the raw request

Use autocurl when you keep sending the same requests to your own backend during development, want them saved in the repo, or want an agent to exercise your API reliably.

Many developers use both: autocurl for the routes they work on every day, curl for everything else.

Next: How to test APIs from the terminal · Install autocurl