Unity AI CLI Bridge

Experimental direct-bridge tooling for Unity MCP.

This repository contains:

• a Go CLI that connects directly to Unity's built-in UnityMCPBridge
• a local Unity companion package under Packages/src/com.hatayama.unity-ai-cli-bridge

The Unity-managed com.unity.ai.assistant package is treated as immutable.
This project does not rely on editing Library/PackageCache.

Architecture

unity-ai-cli
  |- status
  |- doctor
  |- help
  |- recipes
  |- tools
  |- describe
  |- call
  |- wait
  `- mcp serve
        |
        v
UnityMCPBridge direct IPC
        |
        v
Unity Editor + com.unity.ai.assistant

Packages/src/com.hatayama.unity-ai-cli-bridge
  `- companion diagnostics snapshots
        |
        v
Library/UnityAiCliBridge/diagnostics.json
Library/UnityAiCliBridge/tools.json

The relay binary is not part of this runtime path.

Requirements

• Unity project with com.unity.ai.assistant
• Unity MCP enabled in the Editor
• Go 1.25 or later to build the CLI
• approval for the CLI client in Project Settings > AI > Unity MCP

Companion Package

The repository installs a local Unity package from:

• Packages/src/com.hatayama.unity-ai-cli-bridge

The package adds:

• diagnostics snapshots for the CLI
• Editor menu commands for bridge diagnostics
• EditMode tests for the companion layer

The package is wired through Packages/manifest.json.

Build

go build -o ./bin/unity-ai-cli ./cmd/unity-ai-cli

Usage

Recommended human flow:

1. help to see only the Unity tools that are currently enabled
2. help <tool> to understand one tool
3. recipes to see task-oriented workflows
4. call <tool> to execute the tool directly

Show the currently resolved bridge and companion snapshot state:

./bin/unity-ai-cli status --json

Diagnose discovery, heartbeat, companion snapshots, and likely approval issues:

./bin/unity-ai-cli doctor --json

Wait for bridge readiness:

./bin/unity-ai-cli wait --for=bridge

List available Unity tools from the live direct bridge:

./bin/unity-ai-cli tools --json

List human-oriented help for the currently enabled Unity tools only:

./bin/unity-ai-cli help --json

Show detailed help for one enabled Unity tool:

./bin/unity-ai-cli help Unity_GetConsoleLogs --json

Show recipes that are currently available for the enabled Unity tools:

./bin/unity-ai-cli recipes --json

Show one task-oriented recipe:

./bin/unity-ai-cli recipes inspect-console --json

Filter tools by catalog category:

./bin/unity-ai-cli tools --category capture

Describe one Unity tool:

./bin/unity-ai-cli describe Unity_GetConsoleLogs --json

Call a Unity tool directly:

./bin/unity-ai-cli call Unity_GetConsoleLogs --json-args '{"maxEntries":5,"includeStackTrace":false}'

Expose Unity tools as an MCP stdio server:

./bin/unity-ai-cli mcp serve

help and recipes are driven by the current live enabled tool set from Unity. If a tool is disabled in Project Settings > AI > Unity MCP, it will not appear there.

Approval Flow

The first direct connection may stay pending until Unity approves the CLI.

If doctor, tools, describe, call, or mcp serve reports an approval-related issue:

1. Open Edit > Project Settings > AI > Unity MCP
2. Check Pending Connections
3. Approve the unity-ai-cli client

This approval is handled from the Unity settings UI, not a modal dialog.

Verification

Build the CLI:

go build -o ./bin/unity-ai-cli ./cmd/unity-ai-cli

Check the enabled tool catalog:

./bin/unity-ai-cli help --json
./bin/unity-ai-cli help Unity_GetConsoleLogs --json
./bin/unity-ai-cli recipes --json
./bin/unity-ai-cli recipes inspect-console --json
./bin/unity-ai-cli tools --category capture

Expected results:

• help --json lists only the tools that are currently enabled in Unity
• help Unity_GetConsoleLogs --json includes summary, usage guidance, arguments, and examples
• recipes --json lists only recipes whose required tools are currently enabled
• recipes inspect-console --json shows the console inspection workflow
• tools --category capture shows only capture tools

Development

Install the local Go quality tools:

brew install golangci-lint
go install golang.org/x/vuln/cmd/govulncheck@$(cat .govulncheck-version)

Verify local tool availability:

sh scripts/go-guardrails.sh doctor

Enable the shared local pre-commit hook:

git config core.hooksPath .githooks

Format Go files:

sh scripts/go-guardrails.sh fmt

Run the full local Go guardrail suite:

sh scripts/go-guardrails.sh check

git commit runs fmt-check, go test, go vet, and golangci-lint automatically when the staged changes include Go-related files. It skips commits that do not touch the Go toolchain or Go source files.

Run Go tests:

GOCACHE=/tmp/unity-ai-cli-bridge-go-cache go test ./...

Compile the Unity project:

uloop compile

Run companion package EditMode tests:

uloop run-tests --test-mode EditMode --filter-type regex --filter-value "BridgeDiagnosticsServiceTests|BridgeDiagnosticsSnapshotWriterTests"

Run the live end-to-end smoke test:

sh scripts/live-e2e.sh

Specification

• V1 specification

License

MIT