Odel
JWT Decoder API

JWT Decoder API

@br0ski777TypeScriptMITUpdated 4 days ago

Decode JWT tokens — inspect header, payload, claims, expiry. x402 micropayment.

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Server endpointStreamable HTTPNo authProbed

Registry lists this as SSE; the live endpoint answered over Streamable HTTP.

https://jwt-decoder.api.klymax402.com/mcp

This is the third-party server itself — Odel doesn't run it. Hitting this URL directly talks straight to the upstream server with no auth or proxying. Connect through Odel to front it with managed auth.

JWT Decoder API

MCP Server x402 License: MIT

Decode and inspect JWT tokens without verification. Extracts header, payload, claims, expiry, and signature algorithm. 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.):

{
  "mcpServers": {
    "jwt-decoder": {
      "url": "https://jwt-decoder.api.klymax402.com/mcp"
    }
  }
}

Quickstart -- HTTP (x402)

curl -X POST "https://jwt-decoder.api.klymax402.com/api/decode" \
  -H "Content-Type: application/json" \
  -d '{"token":"..."}'
# -> 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
security_decode_jwtPOST/api/decode$0.003Decode a JWT token without signature verification

security_decode_jwt

Use this when you need to decode and inspect a JWT token without verifying its signature. Returns the full header, payload, and expiration status.

Parameters

NameTypeRequiredDescription
tokenstringyesThe JWT token to decode (format: header.payload.signature)

Example response:

{"header":{"alg":"RS256","typ":"JWT"},"payload":{"sub":"user123","exp":1720000000},"issuedAt":"2025-01-01T00:00:00Z","expiresAt":"2025-07-03T00:00:00Z","isExpired":false}

When to use: debugging authentication issues, inspecting token claims before API calls, or verifying token expiry. Use this BEFORE making authenticated requests to check if a token needs refreshing.

Not for: hashing data (use crypto_generate_hash), base64 encoding/decoding (use utility_encode_base64), password analysis (use security_check_password).

Example agent prompts

  • "Decode and inspect a JWT token without verifying its signature"

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