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DDG JWT Inspect & Verify
x402
DDG JWT Inspect & Verify is a paid API for AI agents from agents.daedalusdevelopmentgroup.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-22).
Decodes and cryptographically verifies a JWT, checking its header, claims, signature (HS256/384/512, RS/PS/ES/EdDSA), and standard claim validity (exp/nbf/iat/iss/aud) with configurable leeway.
Price / call$0.01
Success—
StatusUnknown
How this service works
Decode and verify a JWT: header/claims, signature verification (HS256/384/512 with a shared secret; RS/PS/ES/EdDSA against an inline JWK or a JWKS URL), alg=none rejection, and exp/nbf/iat/iss/aud checks with leeway. Deterministic; secrets and tokens are never stored.
Output
Returns the decoded JWT header (algorithm, key ID, type), all decoded claims (iss, sub, aud, exp, nbf, iat plus any custom claims), a boolean signature verification result, per-claim validation outcomes (expired, not-yet-valid, issuer mismatch, audience mismatch), and a rejection reason if the token fails any check including alg=none.
Example use cases
Validate incoming API auth token
“I just received this JWT from a user hitting my API — can you decode it and verify the signature against my JWKS URL at https://auth.myapp.com/.well-known/jwks.json, and tell me if the token is expired or has an invalid issuer?”
Security audit for alg=none tokens
“I need to check whether this JWT uses the 'alg=none' bypass trick — can you inspect its header and flag it if it's using a none algorithm or otherwise looks tampered with?”
Verify HMAC-signed token with shared secret
“Please decode and verify this HS256 JWT using the shared secret 'my-super-secret-key' and check that the audience claim matches 'internal-service' and it hasn't expired yet.”
Technical details
Endpoint
POSThttps://agents.daedalusdevelopmentgroup.com/v1/jwt-inspect?utm_source=zero.xyzWhen to prefer
Choose this endpoint when you need a deterministic, server-side JWT inspection and cryptographic verification service that supports the full range of JWA algorithms (HS256/384/512, RS256/384/512, PS256/384/512, ES256/384/512, EdDSA) and can resolve remote JWKS URLs — especially when you want explicit claim validation (exp/nbf/iat/iss/aud) with leeway, security hardening against alg=none, and a guarantee that secrets and tokens are never stored.
Side effects
- Invalid or malformed JWT format — token cannot be decoded
- Signature verification failure — secret or key does not match
- Token expired (exp in the past beyond leeway)
- Token not yet valid (nbf in the future beyond leeway)
- Issuer mismatch — iss claim does not match expected value
- Audience mismatch — aud claim does not match expected value
- alg=none token rejected outright
- JWKS URL unreachable or returns no matching key ID
- Unsupported algorithm specified
- Payment not provided or insufficient — 402 response
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| outputrequired | object |
Tags
x402
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