SKILL.md
REST HTTP Caller Skill
This skill enables you to make HTTP/REST API calls using a simple C# script that runs with dotnet run.
Prerequisites
- .NET 10 or later installed (for
dotnet run app.cssupport) - Network access to the target endpoint
Usage
Run the HTTP caller script using dotnet run:
dotnet run HttpCaller.cs -- <METHOD> <URL> [OPTIONS]Arguments
| Argument | Required | Description |
|---|---|---|
METHOD |
Yes | HTTP method: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS |
URL |
Yes | The full URL to call (must include scheme, e.g., https://) |
Options
| Option | Description | Example |
|---|---|---|
--header or -H |
Add a header (can be used multiple times) | --header "Authorization: Bearer token123" |
--body or -b |
Request body (JSON string) | --body '{"name": "test"}' |
--body-file or -f |
Read request body from a file | --body-file request.json |
--timeout or -t |
Request timeout in seconds (default: 30) | --timeout 60 |
--output or -o |
Save response body to a file | --output response.json |
--verbose or -v |
Show detailed request/response info | --verbose |
--help or -? |
Show help and usage information | --help |
Examples
GET Request
dotnet run HttpCaller.cs -- GET https://api.example.com/usersGET with Authentication Header
dotnet run HttpCaller.cs -- GET https://api.example.com/users --header "Authorization: Bearer YOUR_TOKEN_HERE"POST with JSON Body
dotnet run HttpCaller.cs -- POST https://api.example.com/users --header "Content-Type: application/json" --body '{"name": "John Doe", "email": "[email protected]"}'PUT Request with Body from File
dotnet run HttpCaller.cs -- PUT https://api.example.com/users/123 --header "Content-Type: application/json" --body-file update-user.jsonDELETE Request
dotnet run HttpCaller.cs -- DELETE https://api.example.com/users/123 --header "Authorization: Bearer YOUR_TOKEN_HERE"Multiple Headers
dotnet run HttpCaller.cs -- POST https://api.example.com/data --header "Content-Type: application/json" --header "Authorization: Bearer TOKEN" --header "X-Custom-Header: value" --body '{"data": "test"}'Verbose Output with Timeout
dotnet run HttpCaller.cs -- GET https://api.example.com/slow-endpoint --timeout 120 --verboseSave Response to File
dotnet run HttpCaller.cs -- GET https://api.example.com/large-data --output data.jsonScript Location
The HTTP caller script is located at: [HttpCaller.cs](./HttpCaller.cs)
Output Format
The script outputs:
- Status: HTTP status code and reason phrase
- Headers: Response headers (in verbose mode)
- Body: Response body (JSON is automatically formatted)
Example Output
=== HTTP Response ===
Status: 200 OK
Body:
{
"id": 123,
"name": "John Doe",
"email": "[email protected]"
}Verbose Output
=== HTTP Request ===
Method: POST
URL: https://api.example.com/users
Headers:
Content-Type: application/json
Authorization: Bearer ***
Body:
{"name": "John Doe", "email": "[email protected]"}
=== HTTP Response ===
Status: 201 Created
Headers:
Content-Type: application/json
X-Request-Id: abc123
Body:
{
"id": 456,
"name": "John Doe",
"email": "[email protected]"
}Common Use Cases
- Testing APIs: Quickly test REST endpoints during development
- Fetching Data: Retrieve data from external services
- Automation: Integrate API calls into workflows
- Debugging: Use verbose mode to inspect request/response details
- Authentication Testing: Test various auth mechanisms (Bearer, API Key, Basic)
Error Handling
The script provides clear error messages for common issues:
- Network errors
- Invalid URLs
- Timeout errors
- HTTP error status codes (4xx, 5xx)
Tips for LLM Usage
When using this skill, fill in:
- METHOD: Choose the appropriate HTTP method for the operation
- URL: Provide the complete endpoint URL
- Headers: Add necessary headers like
Content-Type,Authorization, etc. - Body: For POST/PUT/PATCH, provide the request body as JSON
Always include Content-Type: application/json header when sending JSON data.