expectedHeadSha

The expected SHA of the pull request's HEAD ref (string, optional)

SERVERGitHub SOURCEoci:ghcr.io/aifity/omnigit-mcp:0.5.0

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-aifity-omnigit-mcp/expectedheadsha.md

WHAT IT DOES

What expectedHeadSha does on GitHub

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

RISK

Why expectedHeadSha is rated Low

This tool retrieves a property value (a git commit SHA) for comparison or validation purposes. It has no side effects, does not execute operations, and does not modify any data. The context of pull request metadata inspection places it squarely in the Read category. The blast radius of misuse is minimal since it only exposes immutable commit identifiers already public in the repository.

From the tool's definition Tool returns or references 'the expected SHA of the pull request's HEAD ref' — a read-only field that retrieves commit identification metadata without modifying state.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs expectedHeadSha safely

PolicyLayer is an MCP gateway: it sits between your AI agents and GitHub, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For expectedHeadSha, this is the rule to start with:

expectedHeadSha Allowed

expectedHeadSha is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "expectedHeadSha": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect GitHub, apply this rule, and every expectedHeadSha call is checked against it from then on.

FAQ

Questions about expectedHeadSha

What does the expectedHeadSha tool do? +

The expected SHA of the pull request's HEAD ref (string, optional). It is categorised as a Read tool in the GitHub MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on expectedHeadSha? +

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

What risk level is expectedHeadSha? +

expectedHeadSha is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit expectedHeadSha? +

Yes. Add a rate_limit block to the expectedHeadSha 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 expectedHeadSha completely? +

Set action: deny in the PolicyLayer policy for expectedHeadSha. 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 expectedHeadSha? +

expectedHeadSha is provided by the GitHub MCP server (oci:ghcr.io/aifity/omnigit-mcp:0.5.0). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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