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For a quick, portable REST API call, use curl. Choose HTTPie when readable commands and easy-to-scan responses matter most. For repeatable tests built around saved requests, environments, and assertions, use Postman CLI or Newman.

All three send HTTP requests from the terminal; the right choice depends on whether you need a lightweight command, an interactive API client, or a collection-based testing workflow.

What a REST API CLI does

A REST API command-line interface sends an HTTP request to an endpoint. The request has a method, such as GET or POST, and a URL or path. Depending on the API, it may also need headers, authentication, query parameters, or a request body. GitHub’s REST API guide describes these request components and demonstrates making requests with both GitHub CLI and curl: GitHub REST API guide.

For example, a command might ask an endpoint for data, include an authorization header, and send JSON. The CLI is the client; the API’s documentation determines the correct endpoint, method, parameters, and payload.

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Make a basic API request

Suppose an API provides a URL such as https://api.example.com/v1/items. A simple GET request with curl is:

curl https://api.example.com/v1/items

A POST request with JSON can be written as:

curl -X POST https://api.example.com/v1/items -H 'Content-Type: application/json' -d '{"name":"example"}'

Replace the example URL and payload with values from the API’s documentation. The -H option supplies a header, while -d sends the body. For an authenticated endpoint, add the authentication method the API requires; do not assume every service uses the same header or token format.

curl vs. HTTPie vs. Postman CLI and Newman

These tools can all make HTTP requests, but they suit different ways of working.

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Tool Request authoring and output State and testing Best fit
curl Compact, widely available command syntax; detailed behavior is controlled with options. Cookies, variables, and assertions are generally managed by your scripts or other tools. Portable one-off requests and shell automation.
HTTPie Readable request syntax with JSON-friendly, formatted output and interactive debugging features. Supports persistent named sessions; can be used in scripts and pipelines. Interactive API exploration and commands that are easy to read and share.
Postman CLI / Newman Postman request commands and collection workflows. Supports environments, scripts, assertions, and repeatable collection runs. Team test suites and CI/CD workflows built around Postman collections.

Use curl for portable, low-level requests

curl is a practical baseline when you want a command that can be embedded in shell scripts or run in varied environments. Its options give control over methods, headers, request data, and other HTTP details, though commands can become harder to scan as options accumulate.

For an API key sent in a header, for example, the request shape may be:

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curl https://api.example.com/v1/items -H "X-API-Key: $API_KEY"

The header name is only an example: follow the API provider’s authentication documentation. This pattern reads the secret from an environment variable instead of placing its value directly in the command. Avoid committing credentials to scripts or repositories, and use your CI platform’s secret storage for pipeline credentials.

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Use HTTPie for readable interactive requests

HTTPie’s official documentation gives its command synopsis as http [flags] [METHOD] URL [ITEM [ITEM]]. Its syntax is designed to make request fields and headers more legible, and its output is formatted for convenient inspection. The project describes it as “A simple yet powerful command-line HTTP and API testing client for the API era.” See the HTTPie CLI page.

A JSON POST equivalent to the earlier curl example is:

http POST https://api.example.com/v1/items name=example

HTTPie infers JSON handling for this kind of field syntax, while curl makes the JSON content header and body explicit. HTTPie also documents forms and file uploads, HTTPS, proxies, arbitrary request data, downloads, and Basic, Digest, Bearer, token, and netrc-based authentication.

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For authentication, use the scheme required by the API. HTTPie’s documented Bearer-authentication form is:

http GET https://api.example.com/v1/items "Authorization:Bearer $API_TOKEN"

Check the installed version’s help or documentation for the exact syntax supported by your setup. HTTPie documents Linux, macOS, Windows, and FreeBSD support, and its documentation identifies version 3.2.4 dated 2024-11-01: HTTPie CLI documentation.

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Use Postman CLI or Newman for repeatable API tests

When requests are maintained as a team collection rather than as individual shell commands, Postman’s command-line tools connect API calls to saved workflow assets. The postman request command can test and debug HTTP requests from the command line. Postman documents support for GET, POST, PUT, DELETE, PATCH, HEAD, and OPTIONS, along with authentication, environment variables, test assertions, and request scripts: Postman request command documentation.

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Postman describes its CLI as a command-line companion. Newman is its open-source command-line collection runner, intended for integrating collection runs into CI/CD: Postman CLI overview. Use this route when a team needs to run the same collection repeatedly, check assertions, or supply environment-specific values as part of a pipeline.

Handle credentials safely in scripts and CI

Authentication is part of the request design, not an afterthought. The exact method—such as a bearer token or API key—comes from the API provider. Keep secret values out of source control, shared command examples, and committed collection exports. In local scripts, read credentials from a protected environment variable or an appropriate credential store; in CI, use the platform’s secret-management feature and inject the value only into the job that needs it.

  • Use the API’s documented authentication scheme and header names.
  • Do not place real credentials directly in commands that may be saved in shell history or logs.
  • Keep secrets separate from collection files and other version-controlled configuration.
  • Limit pipeline access to the credentials required by that job.

Choose the tool for your workflow

  • Choose curl for portable, low-level calls and shell automation where explicit options are useful.
  • Choose HTTPie for readable interactive requests, convenient JSON handling, sessions, and response inspection.
  • Choose Postman CLI or Newman for maintained collections, environments, assertions, request scripts, and CI/CD runs.

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