# AgentTools JWT Decoder

> AgentTools JWT Decoder is a paid API for AI agents from agentstoolshub.com, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-12).

Decodes a JWT's header and payload into readable JSON without verifying the signature — exp and iat claims are rendered as human-readable dates.

## Facts

- Endpoint: GET https://agentstoolshub.com/api/v1/dev/jwt-decoder?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agenttools-jwt-decoder-c03d6ec2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_9gbak9Wfgj_bzgW2Cec1h

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 agenttools-jwt-decoder-c03d6ec2
```

Example prompt: Can you decode this JWT for me so I can see what's in the header and payload — eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c — I don't need signature verification, just want to read the contents.

## When to prefer this

Use this endpoint when you need to quickly inspect the contents of a JWT for debugging, logging, or informational purposes without access to the signing secret. It is ideal for development workflows, token introspection in read-only pipelines, or when you only care about the claims rather than authenticity. Do NOT use this when cryptographic signature verification is required for security-sensitive decisions.

## Known failure modes

- Malformed or non-JWT string returns a parsing error
- Missing 'token' query parameter returns a 400 or validation error
- A token with fewer than two base64 segments (header.payload) may fail to decode
- Non-standard encoding variants that fall outside standard or URL-safe base64 may cause errors

## How this service works

Decode a JSON Web Token's header and payload to readable JSON. Pure decoding: signatures are NOT verified and no secret is needed. Accepts standard and URL-safe base64 with or without padding; claims like exp and iat are rendered as dates. Use this when an agent needs to decode header and payload — no verification.

## Output

Returns a JSON object with two keys: the decoded header (algorithm, token type, etc.) and decoded payload (all claims, with exp and iat rendered as human-readable date strings). No signature verification is performed and no secret is required.

## 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": {
      "token": {
       "type": "string",
       "description": "header.payload.signature"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agenttools-jwt-decoder-c03d6ec2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentstoolshub.com](https://www.zero.xyz/host/agentstoolshub.com/llms.txt)