flake-update
Updates flake lock file inputs and returns structured information about what was updated.
This record as markdown: /tools/io-github-dave-london-lint/flake-update.md
What flake-update does on Lint
AI agents use flake-update to create or update resources in Lint, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Lint environment.
Why flake-update is rated Medium
The tool modifies a flake lock file by updating its inputs, which is a reversible write operation. While this affects the project's dependency lock file (potentially significant), it doesn't irreversibly delete data or execute arbitrary code with unpredictable effects. Lock file updates are typically reversible through version control or re-running the update with different parameters.
From the tool's definition Tool description states it "Updates flake lock file inputs" - this is a modification operation that changes files.
Attacks that exploit this kind of access
The rule that runs flake-update safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Lint, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For flake-update, this is the rule to start with:
flake-update stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Lint, apply this rule, and every flake-update call is checked against it from then on.
Questions about flake-update
Updates flake lock file inputs and returns structured information about what was updated. It is categorised as a Write tool in the Lint MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Lint MCP server in PolicyLayer and add a rule for flake-update: 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 Lint. Nothing to install.
flake-update 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 flake-update 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 flake-update. 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.
flake-update is provided by the Lint MCP server (Dave-London/Pare). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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