gnt — Claude Code MCP server: what it does, how to install
A policy check over MCP: the agent asks before it acts, gnt answers allowed, blocked or needs_human, and each verdict points to a rule file in your repo.
claude mcp add --transport http gnt https://api.gntai.dev/mcpWhat gnt does
gnt keeps an agent rulebook in git. Rules are markdown files with YAML frontmatter under rules/, and a merged pull request is what makes one official. That rules out the dashboard click: the approval is the merge. Before an agent refunds a customer, deletes a record or sends a message, it calls check_action over MCP and gets allowed, blocked or needs_human plus a one-line reason.
The endpoint carries five tools. Alongside the action check there is search_rules with optional tag filtering, get_rule for a single rule and its provenance, and list_skill_packs with get_skill_pack for compiled skill packs. Lookups hit gnt's own store rather than cloning your repository on every call.
needs_human is the fail-closed answer: nothing approved covers the action, retrieval broke, the check could not finish. No guessing. The CLI wants Node >=22.13, so a startup version error means updating Node and confirming with node --version. Rule extraction in gnt prebrain runs in cloud mode by default, sending source text to Anthropic's API; pass --mode local against a local Ollama daemon for on-device work.
What it helps with
- block a refund before the agent sends it
- trace a verdict back to the rule file
- add a new rule through a pull request
- search approved rules by tag
- see who signed off a rule and when
Example prompts for the agent
- Before you delete these records, run
check_actionand quote the rule you relied on. - Use
search_rulesto list approved rules taggedfinance. - Pull up
refund-approval-thresholdwithget_ruleand tell me who approved it.
How to install gnt
Platform CLI: remote server
claude mcp add --transport http gnt https://api.gntai.dev/mcpPlatform CLI: remote server
codex mcp add gnt --url https://api.gntai.dev/mcpConfig file
{
"mcpServers": {
"gnt": {
"url": "https://api.gntai.dev/mcp"
}
}
}Config file
{
"servers": {
"gnt": {
"type": "http",
"url": "https://api.gntai.dev/mcp"
}
}
}Platform CLI: remote server
gemini mcp add -t http gnt https://api.gntai.dev/mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about gnt
How do I install gnt in Claude Code?
Run claude mcp add --transport http gnt https://api.gntai.dev/mcp. That registers the remote endpoint over HTTP.
What does gnt do?
It gives an agent a policy check over MCP: check_action returns a verdict with the rule file behind it, and companion tools search, fetch and list those rules.
Where do the rules actually live?
In the GitHub repo you connect, as markdown files under rules/, and in gnt's own database. The MCP tools read that store instead of cloning the repo on each call.
