Medium Risk

create_branch

Create a new branch in a GitHub repository

How to control create_branch ↓

What create_branch does on GitHub MCP Server Plus

AI agents use create_branch to create or update resources in GitHub MCP Server Plus — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your GitHub MCP Server Plus environment.

Medium Risk

Why create_branch needs a policy

Creating a branch is a write operation that creates new metadata/references in the repository. While branches can be deleted later, the action itself is reversible and does not permanently destroy data.

From the tool's definition Tool name is 'create_branch' and description states it 'Create a new branch in a GitHub repository'. This is a reversible creation operation that modifies repository state but does not delete or overwrite existing data.

Documented attack patterns abuse exactly the kind of access create_branch gives an agent:

How to control create_branch

PolicyLayer is an MCP gateway — it sits between your AI agents and GitHub MCP Server Plus, and nothing reaches the server without passing your rules. This is the rule we recommend for create_branch:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_branch": {
      "limits": [
        {
          "counter": "create_branch_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

create_branch 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.

  1. Create a free account and register GitHub MCP Server Plus — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

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Related tools and policies

Go deeper

Questions about create_branch

What does the create_branch tool do? +

Create a new branch in a GitHub repository. It is categorised as a Write tool in the GitHub MCP Server Plus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_branch? +

Register the GitHub MCP Server Plus MCP server in PolicyLayer and add a rule for create_branch: 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 GitHub MCP Server Plus. Nothing to install.

What risk level is create_branch? +

create_branch is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit create_branch? +

Yes. Add a rate_limit block to the create_branch 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.

How do I block create_branch completely? +

Set action: deny in the PolicyLayer policy for create_branch. 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.

What MCP server provides create_branch? +

create_branch is provided by the GitHub MCP Server Plus MCP server (phialsbasement/mcp-github-server-plus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every GitHub MCP Server Plus tool call.

Start from GitHub MCP Server Plus, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

18 GitHub MCP Server Plus tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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