Webhook Tester API

io.github.Br0ski777Published by GitHub account Br0ski777v1.1.0Updated Nov 2, 2026

Test webhook endpoints — send requests, measure latency, validate responses. x402 micropayment.

VerifiedSSEWeb executableDeveloper ToolsSecurity & Monitoring

Overview

AI-generated overview

Remote MCP server that lets an assistant send test requests to webhook endpoints and inspect the response, latency and TLS details, paid per call in USDC.

What you can do
  • Send a test HTTP request (POST, PUT, PATCH or DELETE) to an https webhook URL with custom headers, JSON body and timeout
  • Read back the full JSON response: status code, response body, request and response sizes
  • Measure latency and inspect TLS protocol and cipher of the endpoint
  • Pay per call through the x402 protocol instead of an API key or signup
When to use it
Useful when debugging webhook integrations or API callbacks, checking that an endpoint is reachable and returns the expected status and body, or comparing webhook response times and TLS settings. Not intended for scraping, screenshots or header security audits.
Requirements
A remote SSE endpoint at the provider's host; nothing to install locally. No API key or signup, but each call is paid in USDC on Base L2 through the x402 protocol, so an x402-capable client or wallet that can answer the 402 payment challenge is needed. Network access to the provider and to the webhook URL being tested.
Before you install
Every call costs money (listed at $0.005 per test) and is settled in USDC on Base through a wallet, so spending should be capped and reviewed. The server sends real requests to whatever URL you give it, including any custom headers and body, so do not pass secrets or production endpoints carelessly. Payment goes through third-party facilitators (Coinbase CDP, PayAI), and the tested endpoint sees the request.

Installation

In SourceWeft

  1. Open Webhook Tester API in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via SSE. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.Br0ski777%2Fwebhook-tester/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "webhook-tester-api": {
      "type": "sse",
      "url": "https://webhook-tester.api.klymax402.com/mcp"
    }
  }
}

README

Webhook Tester API

[MCP Server] [x402] [License: MIT]

Test webhook endpoints -- send POST/PUT/PATCH/DELETE with custom headers and payloads. Measure latency and TLS. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.

Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.

Quickstart -- MCP

Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):

json
{  "mcpServers": {    "webhook-tester": {      "url": "https://webhook-tester.api.klymax402.com/mcp"    }  }}

Quickstart -- HTTP (x402)

bash
curl -X POST "https://webhook-tester.api.klymax402.com/api/test" \  -H "Content-Type: application/json" \  -d '{"url":"https://example.com"}'# -> 402 Payment Required, with an x402 payment challenge in the response body

Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.

Tools

ToolMethodPathPriceDescription
api_test_webhookPOST/api/test$0.005Send a test request to a webhook URL and analyze the response

api_test_webhook

Use this when you need to test a webhook endpoint by sending a request with custom headers, body, and method. Returns full response data in JSON.

Parameters

NameTypeRequiredDescription
urlstringyesWebhook URL to test (must be https)
methodstringnoHTTP method: POST, PUT, PATCH, DELETE (default: POST)
headersobjectnoCustom headers as key-value pairs
bodyobjectnoJSON body to send
timeoutnumbernoTimeout in seconds (default: 10, max: 30)

Example response:

json
{"url":"https://hooks.example.com/callback","method":"POST","statusCode":200,"responseBody":{"received":true},"latency":142,"tlsInfo":{"protocol":"TLSv1.3","cipher":"AES-256-GCM"},"requestSize":256,"responseSize":48}

When to use: testing webhook integrations, debugging API callbacks, validating endpoint availability, and measuring webhook response times.

Not for: web scraping (use web_scrape_to_markdown), screenshot capture (use capture_screenshot), HTTP header security audit (use network_analyze_headers).

Example agent prompts

  • "Test a webhook endpoint by sending a request with custom headers, body, and method"

Payment

  • Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
  • Network: Base L2 (eip155:8453)
  • Asset: USDC
  • Facilitator: Coinbase CDP (primary), PayAI (fallback)
  • Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)

Part of klymax402

100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.

License

MIT

Source: README.md at commit 60f72fe

Tools

0
SourceWeft has not read this server's tools yet.

Version history

1
  1. v1.1.0LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declaredRequired10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts