Squire MCP server

Squire

Squire is a transparent local execution and verification layer for coding agents. It keeps common repository reads hot and continuously maintains whether the current declared workspace state is verified.

The agent keeps using ordinary terminal commands. Before Codex starts a local read-only command, Squire checks current state and either replays a proven mmap observation or executes a small bounded operation over hash-verified current file bytes. A valid hit returns the exact stdout, stderr, and exit status. Every miss follows Codex's original native execution path.

Install

curl -fsSL https://raw.githubusercontent.com/reidgoodbar/squire/main/install.sh | bash

The installer verifies matching Squire and Squire-Codex release archives and installs the driver, Codex runtime helper, and host-native Squire runtime to ~/.local/bin. It does not change Codex authentication or configuration. Supported hosts are macOS and Linux on amd64 or arm64.

Check the installation:

squire doctor

doctor exits nonzero when any required driver, helper, runtime, or ABI component is missing.

Use

Start from any directory:

squire codex

That is the complete user path. There is no setup command, global shell shim, prompt change, MCP tool, preload injection, or VM provisioning step. If Codex moves into a repository later, Squire discovers and prepares that repository from the command's actual cwd.

squire-codex is also installed as a direct convenience command.

Inspect the current repository and runtime:

squire status
squire status --json
squire explain -- git status --short

Continuous Verification

Squire Green runs declared tests, lint, typechecks, and builds natively in the background after repository edits settle. Each result is bound to the exact declared input bytes, check configuration, environment, and executable. A later relevant edit makes that result stale; unrelated edits do not.

# .squire/checks.toml
[[check]]
name = "tests"
command = ["go", "test", "./..."]
inputs = ["**/*.go", "go.mod", "go.sum"]
timeout = "10m"

Repository-provided commands never run silently on first use. Review the file and trust its exact hash once:

squire green trust
squire verify

Any config change revokes trust. squire codex then schedules trusted checks automatically; no second daemon or warm command is required. See docs/GREEN.md for configuration and proof semantics.

What It Accelerates

Production lanes are bounded but cover the common read-only command surface:

forms, including path-scoped diffs and git diff --check, plus bounded git log -N --oneline -- history.

• Git metadata: supported git rev-parse forms and branch discovery.
• Repository reads: supported git status, git ls-files, and git diff

head, tail, nl -ba, file, fixed-string grep/rg, demand-prepared bounded repository rg searches, and tight ls forms.

• File and search reads: bounded cat, ordered single- or multi-range sed -n,

printenv, whoami, id, hostname, and uname forms.

• Environment discovery: supported version probes, which/command -v, safe

including pipes, sequences, redirection to /dev/null, head, tail, bounded sed -n, grep -F, wc -l, and sort.

• Compositions: complete read-only plans over supported sources and filters,

No operation is removed. Builds, tests, edits, installs, mutating Git commands, expansions, unknown shell syntax, sensitive probes, and unsupported variants immediately follow Codex's unchanged native path. A safe cold miss does the same while requesting exact preparation in the background. rg --files remains outside the bounded preparation policy and follows the native path.

Shortened. The full README is on GitHub.