HMAC Generator

Compute an HMAC digest (SHA-256 by default) for a key–message pair.

Free tier eligible — 500 calls/month with a free key from /pricing; x402 pay-per-call above quota.

Parameters

Parameter	Type	Required	Description
`key`	string	required	Secret key
`message`	string	required	Message to authenticate
`algorithm`	string	optional	Hash One of: sha1, sha256, sha512, md5

Call it over MCP (JSON-RPC 2.0)

curl -s https://wingmanprotocol.com/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": "hmac", "arguments": {"key": "example-key", "message": "hello"}}}'

Or plain HTTP

curl -s https://wingmanprotocol.com/tools/hmac \
  -H 'Content-Type: application/json' \
  -d '{"key": "example-key", "message": "hello"}'

Try it live

Edit the JSON and run it — this POSTs to https://wingmanprotocol.com/tools/hmac from your browser.

This tool is x402-metered — agents pay per call with USDC on Base. The 402 response below is the standard x402 payment-requirements envelope: sign the EIP-3009 authorization and retry with the X-Payment header, or get a free key at /pricing (500 calls/month, no card, no crypto).