# Duo Data Utilities – JWT Decoder > Duo Data Utilities – JWT Decoder is a paid API for AI agents from api.duoleads.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-10-02). Decodes a JWT without signature verification, returning header, claims, payload, signature info, and computed time-claim analysis (expiry, not-before, remaining lifetime). ## Facts - Endpoint: GET https://api.duoleads.com/v1/code/jwt?utm_source=zero.xyz - Price: $0.05/call - Payment: x402 - Status: unknown - Last checked: 2026-10-02 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/duo-data-utilities-jwt-decoder-0a5806b9 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_v_-iDFtlQ_4PgXX7cdX89 Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability duo-data-utilities-jwt-decoder-0a5806b9 ``` Example prompt: Can you decode this JWT for me and tell me if it's expired, what algorithm it uses, and show me all the claims? Here's the token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c ## When to prefer this Use this endpoint when you need to inspect the contents of a JWT token quickly — to read claims, check expiry timing, or debug token structure — without needing to verify the signature. It is ideal for debugging, logging, and introspection workflows where the signature is already trusted or irrelevant. Do not use it as a security gate or trust decision; it explicitly does not verify signatures. ## Known failure modes - Token is malformed or missing a part — returns structural error indicating which part is absent - Invalid base64url encoding in header or payload — returns parse error - Algorithm is 'none' — reported as a warning in the warnings array - Token exceeds 8192 characters — rejected by input validation - Invalid 'at' timestamp format (not RFC 3339 or epoch seconds) — returns validation error - Network or service error — HTTP 5xx response ## How this service works Decode a JSON Web Token without verifying it: returns the header, the claims, the signature length and algorithm, and a computed view of the time claims — whether exp has passed, whether nbf is in the future, and the remaining lifetime in seconds against a supplied or current instant. Reports structural problems such as a missing part, invalid base64url or an alg of none. It does not and cannot verify the signature; do not use it to decide trust. ## Output A JSON object containing the decoded JWT header (e.g. alg, typ, kid), full payload/claims (all registered and custom fields), number of parts, signature byte length, whether the structure is valid, any warnings (e.g. alg:none), and a computed time block showing whether exp has passed, whether nbf is still in the future, the age in seconds, and remaining lifetime — all evaluated against the supplied or current timestamp. The signature_verified field is always false since no verification is performed. ## Request schema (JSON Schema) ```json { "type": "object", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "input" ], "properties": { "input": { "type": "object", "required": [ "type", "method" ], "properties": { "type": { "type": "string", "const": "http" }, "method": { "enum": [ "GET" ], "type": "string" }, "queryParams": { "type": "object", "required": [ "token" ], "properties": { "at": { "type": "string", "maxLength": 64, "description": "Instant to evaluate exp/nbf against: RFC 3339 or epoch seconds. Default now." }, "token": { "type": "string", "maxLength": 8192, "description": "The JWT to decode (not verified). At most 8192 characters." } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object", "required": [ "ok", "route", "version", "data", "meta" ], "properties": { "ok": { "const": true }, "data": { "type": "object", "required": [ "valid_structure", "header", "payload", "alg", "typ", "kid", "signature_bytes", "parts", "claims", "time", "signature_verified", "warnings", "reason" ], "properties": { "alg": { "type": [ "string", "null" ] }, "kid": { "type": [ "string", "null" ] }, "typ": { "type": [ "string", "null" ] }, "time": { "type": "object", "required": [ "evaluated_at", "expired", "not_yet_valid", "expires_in_seconds", "age_seconds" ], "properties": { "expired": { "type": [ "boolean", "null" ] }, "age_seconds": { "type": [ "integer", "null" ] }, "evaluated_at": { "type": "string" }, "not_yet_valid": { "type": [ "boolean", "null" ] }, "exp … (truncated) ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "ok": true, "data": { "alg": "HS256", "kid": null, "typ": "JWT", "time": { "expired": null, "age_seconds": 274314578, "evaluated_at": "2026-09-28T00:00:00Z", "not_yet_valid": null, "expires_in_seconds": null }, "parts": 3, "claims": { "aud": null, "exp": null, "iat": 1516239022, "iss": null, "jti": null, "nbf": null, "sub": "1234567890" }, "header": { "alg": "HS256", "typ": "JWT" }, "reason": null, "payload": { "iat": 1516239022, "sub": "1234567890", "name": "John Doe" }, "warnings": [], "signature_bytes": 32, "valid_structure": true, "signature_verified": false }, "meta": { "price_usd": "0.05", "disclaimer": "Factual output of a deterministic computation over public data. Provided as is, with no warranty of accuracy, completeness or availability. Not investment, financial, legal, tax, medical or any other professional advice, and not a recommendation. Verify before relying on it. Terms: https://api.duoleads.com/terms", "request_id": "01K6B7Q4ZC8H3F2M9WXR5TYN0D", "computed_at": "2026-09-28T12:00:00.000Z", "deterministic": true }, "route": "/v1/code/jwt", "version": "1.0.0" } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/duo-data-utilities-jwt-decoder-0a5806b9/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from api.duoleads.com](https://www.zero.xyz/host/api.duoleads.com/llms.txt)