brevio-core with Cursor

Cursor gets a hook after each file write, a hook before it stops, rule files and the MCP server.

Set it up

In the repository:

brevio-core init --with hook,mcp

It shows every file it would write as a diff and asks first (--dry-run writes nothing). For Cursor it writes:

File	What it holds
.cursor/hooks.json	a postToolUse hook on Write and a stop hook, both running brevio-core hook run --client cursor
.cursor/rules/brevio-core.mdc	when to run brevio-core and how to read a finding
.cursor/rules/brevio-core-agents.mdc	the same rules as the AGENTS.md block, applied to every request
.cursor/mcp.json	the MCP server, uvx brevio-core==0.9.1 mcp

It also writes the pull-request workflow, the AGENTS.md block and a baseline, as for every client. The hook and MCP files are personal: init lists them in git’s local exclude file, so they are not committed. To wire only the hook, run brevio-core hook install --target cursor. Other hooks in .cursor/hooks.json are kept.

What the agent sees

After each write, the hook scans the lines that file now adds and returns the findings as additional context, one short line each (path:line [RULE] message -> fix). When the agent is about to stop, the hook scans the uncommitted changes and, on a finding, sends one follow-up message asking for the fix; the stop hook is limited to one follow-up, so the agent cannot loop. If the hook fails or runs past its time budget, it lets the agent go on.

The MCP server

The tools are scan, explain, list_rules, learn and, from release 0.3, fix. To add the server by hand, put this in .cursor/mcp.json:

{ "mcpServers": { "brevio-core": { "command": "uvx", "args": ["brevio-core==0.9.1", "mcp"] } } }

scan, the agent hook and the MCP server use no network and send nothing.

Check it

brevio-core hook status