Set a project secret (e.g. STRIPE_SECRET_KEY). Values are write-only and injected as process.env variables in functions. Setting an existing key overwrites it. Use this before deploy, then declare the key with secrets.require.
AI agents use set_secret to create or update resources in Run402 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Run402 environment.
This tool modifies project secrets (e.g., STRIPE_SECRET_KEY) that are injected as environment variables into running functions. While not destructive in the sense of permanent deletion, it allows write access to sensitive credentials that control access to external services and APIs.
From the tool's definition 'Set a project secret' and 'Setting an existing key overwrites it' — creates and modifies configuration data (secrets) that are subsequently injected into function execution environments.
Attacks that exploit this kind of access
Set a project secret (e.g. STRIPE_SECRET_KEY). Values are write-only and injected as process.env variables in functions. Setting an existing key overwrites it. Use this before deploy, then declare the key with secrets.require. It is categorised as a Write tool in the Run402 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Run402 MCP server in PolicyLayer and add a rule for set_secret: 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 Run402. Nothing to install.
set_secret is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the set_secret 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 set_secret. 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.
set_secret is provided by the Run402 MCP server (kychee-com/run402). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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