This record as markdown: /tools/io-tinyfn-tinyfn/base64-decode.md
What base64_decode does on TinyFn
AI agents call base64_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 |
|---|---|---|---|
encoded | string | Yes | Base64 string to decode |
Parameters from the server's own tool schema.
Why base64_decode is rated Low
Base64 decoding is a stateless, deterministic operation that reads and transforms input data into output without modifying any stored state, creating, deleting, or executing arbitrary code. It falls squarely into the Read category. Severity is low because the operation cannot cause harm independent of how an agent uses the decoded output—decoding itself is safe.
From the tool's definition Tool name 'base64_decode' and description 'Decode base64 to text' indicate a data retrieval/transformation operation with no side effects.
Attacks that exploit this kind of access
The rule that runs base64_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 base64_decode, this is the rule to start with:
base64_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 base64_decode call is checked against it from then on.
Questions about base64_decode
Decode base64 to text. It is categorised as a Read tool in the TinyFn MCP Server, which means it retrieves data without modifying state.
base64_decode accepts 1 parameter: encoded. Required: encoded. 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 base64_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.
base64_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 base64_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 base64_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.
base64_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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