jwt_decode
Decode JWT token (without signature verification).
This record as markdown: /tools/io-tinyfn-tinyfn/jwt-decode.md
What jwt_decode does on TinyFn
AI agents call jwt_decode to retrieve information from TinyFn without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
token | string | Yes | JWT token to decode (without verification) |
Parameters from the server's own tool schema.
Why jwt_decode is rated Low
This tool reads and parses data from an existing JWT token without modifying, executing, or deleting anything. Even if misused, it only reveals information already present in the token, posing minimal risk since JWT decoding without verification is a standard, safe read operation.
From the tool's definition Tool name 'jwt_decode' and description 'Decode JWT token (without signature verification)' indicate a retrieval/parsing operation.
Risk signalsHandles credentials or secrets (token)
Attacks that exploit this kind of access
The rule that runs jwt_decode safely
PolicyLayer is an MCP gateway: it sits between your AI agents and TinyFn, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For jwt_decode, this is the rule to start with:
jwt_decode is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect TinyFn, apply this rule, and every jwt_decode call is checked against it from then on.
Questions about jwt_decode
Decode JWT token (without signature verification). It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
jwt_decode accepts 1 parameter: token. Required: token. The full parameter table on this page comes from the server's own tool schema.
Register the TinyFn MCP server in PolicyLayer and add a rule for jwt_decode: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches TinyFn. Nothing to install.
jwt_decode is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the jwt_decode rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for jwt_decode. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
jwt_decode is provided by the TinyFn MCP server (https://api.tinyfn.io/mcp/all/). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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