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API Header Builder & cURL Generator

Request Builder

curl -X GET \
  -H "Content-Type: application/json" \
  -H "Accept: application/json"
  "https://api.example.com/users"

Quick Tips

  • • Use common headers dropdown for quick additions
  • • Query params are automatically URL-encoded
  • • Click "Format JSON" to beautify your request body
  • • Authentication headers are automatically added to generated code
  • • All generated code is ready to copy and use in your project

Last updated:

This tool is provided as-is for convenience. Output should be verified before use in any production or critical context.

Programmatic Access

API Header Builder & cURL Generator is also callable as a free HTTP JSON API at https://aidevhub.io/api/api-header-builder/ — GET with query parameters or POST with a JSON body, no authentication, CORS enabled, 50 requests/day per IP. Responses return { ok, tool, result, meta }. 

curl -s "https://aidevhub.io/api/api-header-builder/?url=https%3A%2F%2Fapi.example.com%2Fusers&method=GET&lang=fetch"

Machine-readable contract: /api/tool/api-header-builder.json All API endpoints: /agents/ LLM site index: /llms.txt

Agent Invocation

Best Path For Builders

Dedicated API endpoint

Deterministic outputs, machine-safe contracts, and production-ready examples.

Dedicated API

https://aidevhub.io/api/api-header-builder/

OpenAPI: https://aidevhub.io/api/openapi.yaml

GET /api/api-header-builder/ GET api-header-builder
POST /api/api-header-builder/ POST api-header-builder

Unified Runtime API

https://aidevhub.io/api/tools/run/?toolId=api-header-builder&a=...

GET and POST are supported at /api/tools/run/ with identical validation and limits.

Limit: 30 req / 60s, input max 256 KB.

How to Use API Header Builder & cURL Generator

  1. 1

    Select HTTP method

    Choose GET, POST, PUT, DELETE, PATCH, or other methods. The method determines what kind of request you're building.

  2. 2

    Build request headers

    Add headers: Content-Type (application/json, application/x-www-form-urlencoded), Authorization (Bearer token, Basic auth), and custom headers your API requires.

  3. 3

    Add request body (if needed)

    For POST/PUT/PATCH, include a JSON body or form data. The tool structures it correctly and validates JSON syntax.

  4. 4

    Generate cURL command

    The tool outputs a ready-to-use cURL command: curl -X POST https://api.example.com/endpoint -H 'Authorization: Bearer token' -d '{...}'. Copy and run in terminal.

  5. 5

    Convert to code

    Some versions generate code snippets in JavaScript (fetch), Python (requests), or Node.js (axios). Paste into your codebase and adapt as needed.

Frequently Asked Questions

What is API Header Builder & cURL Generator?
API Header Builder & cURL Generator helps you visually construct HTTP requests and generate code for cURL, fetch, axios, and Python. It supports custom headers, authentication, and query parameters.
How do I use API Header Builder & cURL Generator?
Set the HTTP method and URL, add headers, authentication, query parameters, and a request body using the visual form. The tool generates ready-to-use code in cURL, JavaScript fetch, axios, or Python.
Does API Header Builder & cURL Generator store or send my data?
No. All processing happens entirely in your browser. Your API details and credentials stay on your device — nothing is sent to any server.
What code output formats are supported?
It generates code for cURL (terminal), JavaScript fetch, JavaScript axios, and Python requests. Each output includes the full request configuration with headers, auth, query params, and body.