# flake-check

Checks a Nix flake for errors and returns structured check results, warnings, and errors.

Agent View of the PolicyLayer registry record for `flake-check`. HTML page: https://policylayer.com/tools/io-github-dave-london-pare-test/flake-check

## Facts

- Tool: `flake-check`
- Server: Test (`Dave-London/Pare`) — https://policylayer.com/tools/io-github-dave-london-pare-test.md
- Homepage: https://github.com/Dave-London/Pare
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "flake-check",
    "arguments": {}
  }
}
```

## Why flake-check is rated Low

This tool performs validation/inspection of Nix flake files and reports findings. It has no side effects, does not modify files, does not execute code, and does not delete anything. It is a pure read operation that queries the state of a Nix flake configuration and returns diagnostic information. Severity is low because misuse would only surface incorrect validation output, posing no direct risk to systems or data.

From the tool's own definition: "Tool 'checks a Nix flake for errors and returns structured check results, warnings, and errors' — the verb is 'checks' and the operation 'returns' results. No data is modified, deleted, or executed."

## Use case

AI agents call flake-check to retrieve information from Test without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Test:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "flake-check": {}
  }
}
```

## Other tools on Test (201)

- `branch` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/branch.md
- `clean` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/clean.md
- `package-clean` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/package-clean.md
- `remove` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/remove.md
- `reset` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/reset.md
- `secret-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/secret-delete.md
- `stash` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/stash.md
- `tag` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/tag.md
- `variable-delete` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/variable-delete.md
- `workspace` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/workspace.md
- `worktree` — Destructive — https://policylayer.com/tools/io-github-dave-london-pare-test/worktree.md
- `add` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/add.md
- `add-package` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/add-package.md
- `ansible-galaxy` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/ansible-galaxy.md
- `ansible-playbook` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/ansible-playbook.md
- `api` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/api.md
- `apply` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/apply.md
- `bazel` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/bazel.md
- `biome-check` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/biome-check.md
- `bisect` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/bisect.md
- `black` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/black.md
- `build` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/build.md
- `bundle-exec` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/bundle-exec.md
- `check` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/check.md
- `cherry-pick` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/cherry-pick.md
- `clippy` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/clippy.md
- `cmake` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/cmake.md
- `compose-build` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/compose-build.md
- `compose-down` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/compose-down.md
- `compose-up` — Execute — https://policylayer.com/tools/io-github-dave-london-pare-test/compose-up.md
- …and 171 more: https://policylayer.com/tools/io-github-dave-london-pare-test.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-dave-london-pare-test · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-dave-london-pare-test