This record as markdown: /tools/io-tinyfn-tinyfn/array-dedupe.md
What array_dedupe does on TinyFn
AI agents call array_dedupe to permanently remove resources in TinyFn, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
| Parameter | Type | Required | Description |
|---|---|---|---|
items | string | Yes | Comma-separated items |
preserve_order | boolean | — | Preserve original order |
Parameters from the server's own tool schema.
Why array_dedupe is rated Critical
An AI agent that decides to call array_dedupe doesn't hesitate, doesn't double-check, and doesn't stop at one. Whatever it removes from TinyFn is gone. There is no undo for destructive operations.
Attacks that exploit this kind of access
The rule that runs array_dedupe 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 array_dedupe, this is the rule to start with:
array_dedupe is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect TinyFn, apply this rule, and every array_dedupe call is checked against it from then on.
Questions about array_dedupe
Remove duplicates from array. It is categorised as a Destructive tool in the TinyFn MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
array_dedupe accepts 2 parameters: items, preserve_order. Required: items. 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 array_dedupe: 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.
array_dedupe is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the array_dedupe 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 array_dedupe. 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.
array_dedupe 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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