* fix: reduce per-frame GC allocations causing editor hitches (issue #577)
Eliminate memory allocations that occurred every frame, which triggered
garbage collection spikes (~28ms) approximately every second.
Changes:
- EditorStateCache: Skip BuildSnapshot() entirely when state unchanged
(check BEFORE building). Increased poll interval from 0.25s to 1.0s.
Cache DeepClone() results to avoid allocations on GetSnapshot().
- TransportCommandDispatcher: Early exit before lock/list allocation
when Pending.Count == 0, eliminating per-frame allocations when idle.
- StdioBridgeHost: Same early exit pattern for commandQueue.
- MCPForUnityEditorWindow: Throttle OnEditorUpdate to 2-second intervals
instead of every frame, preventing expensive socket checks 60+/sec.
Fixes GitHub issue #577: High performance impact even when MCP server is off
* fix: prevent multiple domain reloads when calling refresh_unity (issue #577)
Root Cause:
- send_command() had a hardcoded retry loop (min 6 attempts) on connection errors
- Each retry resent the refresh_unity command, causing Unity to reload 6 times
- retry_on_reload=False only controlled reload-state retries, not connection retries
The Fix:
1. Unity C# (MCPForUnity/Editor):
- Added --reinstall flag to uvx commands in dev mode
- Ensures local development changes are picked up by uvx/Claude Code
- Applies to all client configurators (Claude Code, Codex, etc.)
2. Python Server (Server/src):
- Added max_attempts parameter to send_command()
- Pass max_attempts=0 when retry_on_reload=False
- Fixed type handling in refresh_unity.py (handle MCPResponse objects)
- Added timeout to connection error recovery conditions
- Recovery logic now returns success instead of error to prevent client retries
Changes:
- MCPForUnity/Editor: Added --reinstall to dev mode uvx commands
- Server/refresh_unity.py: Fixed type handling, improved error recovery
- Server/unity_connection.py: Added max_attempts param, disable retries when retry_on_reload=False
Result: refresh_unity with compile=request now triggers only 1 domain reload instead of 6
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* fix: UI and server stability improvements
Unity Editor (C#):
- Fix "Resuming..." stuck state when manually clicking End Session
Clear ResumeStdioAfterReload and ResumeHttpAfterReload flags in
OnConnectionToggleClicked and EndOrphanedSessionAsync to prevent
UI from getting stuck showing "Resuming..." with disabled button
- Remove unsupported --reinstall flag from all uvx command builders
uvx does not support --reinstall and shows warning when used
Use --no-cache --refresh instead for dev mode cache busting
Python Server:
- Add "aborted" to connection error patterns in refresh_unity
Handle WinError 10053 (connection aborted) gracefully during
Unity domain reload, treating it as expected behavior
- Add WindowsSafeRotatingFileHandler to suppress log rotation errors
Windows file locking prevents log rotation when file is open by
another process; catch PermissionError to avoid noisy stack traces
- Fix packaging: add py-modules = ["main"] to pyproject.toml
setuptools.packages.find only discovers packages (directories with
__init__.py), must explicitly list standalone module files
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* docs: improve refresh_unity connection loss handling documentation
Add detailed comments and logging to clarify why connection loss during
compile is treated as success (expected domain reload behavior, not failure).
This addresses PR feedback about potentially masking real connection errors.
The logic is intentional and correct:
- Connection loss only treated as success when compile='request'
- Domain reload causing disconnect is expected Unity behavior
- Subsequent wait_for_ready loop validates Unity becomes ready
- Prevents multiple domain reload loops (issue #577)
Added logging for observability:
- Info log when expected disconnect detected
- Warning log for non-recoverable errors
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* fix: add missing logger import in refresh_unity
Missing logger import causes NameError at runtime when connection
loss handling paths are triggered (lines 82 and 91).
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* fix: address code review feedback on thread safety and semantics
Addresses four issues raised in code review:
1. EditorStateCache.GetSnapshot() - Remove shared cached clone
- Revert to always returning fresh DeepClone() to prevent mutation bugs
- Main GC optimization remains: state-change detection prevents
unnecessary _cached rebuilds (the expensive operation)
- Removed _cachedClone and _cachedCloneSequence fields
2. refresh_unity.py - Fix blocking reason terminology mismatch
- Changed "asset_refresh" to "asset_import" to match activityPhase
values from EditorStateCache.cs
- Ensures asset import is correctly detected as blocking state
3. TransportCommandDispatcher - Fix unsynchronized Count access
- Moved Pending.Count check inside PendingLock
- Prevents data races and InvalidOperationException from concurrent
dictionary access
4. StdioBridgeHost - Fix unsynchronized Count access
- Moved commandQueue.Count check inside lockObj
- Ensures all collection access is properly serialized
All changes maintain the GC allocation optimizations while fixing
thread safety violations and semantic contract changes.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
* fix: address code review feedback on thread safety and timeout handling
- refresh_unity.py: Track readiness explicitly and return failure on timeout
instead of silently returning success when wait loop exits without confirming
ready_for_tools=true
- McpClientConfiguratorBase.cs: Add thread safety guard for Configure() call
in CheckStatusWithProjectDir(). Changed default attemptAutoRewrite to false
and added runtime check to prevent calling Configure() from background threads.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>
EditorApplication.isCompiling can return true in Play mode even when Unity
is not actually compiling, causing MCP tools to incorrectly return
"busy/compiling" errors.
This adds a GetActualIsCompiling() helper that double-checks with
CompilationPipeline.isCompiling via reflection when in Play mode to filter
out these false positives.
Fixes#549
* refactor: Split ParseColorOrDefault into two overloads and change default to Color.white
* Auto-format Python code
* Remove unused Python module
* Refactored VFX functionality into multiple files
Tested everything, works like a charm
* Rename ManageVfx folder to just Vfx
We know what it's managing
* Clean up whitespace on plugin tools and resources
* Make ManageGameObject less of a monolith by splitting it out into different files
* Remove obsolete FindObjectByInstruction method
We also update the namespace for ManageVFX
* refactor: Consolidate editor state resources into single canonical implementation
Merged EditorStateV2 into EditorState, making get_editor_state the canonical resource. Updated Unity C# to use EditorStateCache directly. Enhanced Python implementation with advice/staleness enrichment, external changes detection, and instance ID inference. Removed duplicate EditorStateV2 resource and legacy fallback mapping.
* Validate editor state with Pydantic models in both C# and Python
Added strongly-typed Pydantic models for EditorStateV2 schema in Python and corresponding C# classes with JsonProperty attributes. Updated C# to serialize using typed classes instead of anonymous objects. Python now validates the editor state payload before returning it, catching schema mismatches early.
* Consolidate run_tests and run_tests_async into single async implementation
Merged run_tests_async into run_tests, making async job-based execution the default behavior. Removed synchronous blocking test execution. Updated RunTests.cs to start test jobs immediately and return job_id for polling. Changed TestJobManager methods to internal visibility. Updated README to reflect single run_tests_async tool. Python implementation now uses async job pattern exclusively.
* Validate test job responses with Pydantic models in Python
* Change resources URI from unity:// to mcpforunity://
It should reduce conflicts with other Unity MCPs that users try, and to comply with Unity's requests regarding use of their company and product name
* Update README with all tools + better listing for resources
* Update other references to resources
* Updated translated doc - unfortunately I cannot verify
* Update the Chinese translation of the dev docks
* Change menu item from Setup Window to Local Setup Window
We now differentiate whether it's HTTP local or remote
* Fix URIs for menu items and tests
* Shouldn't have removed it
* Minor edits from CodeRabbit feedback
* Don't use reflection which takes longer
* Fix failing python tests
* Add serialization helpers for ParticleSystem curves and MinMaxCurve types
Added SerializeAnimationCurve and SerializeMinMaxCurve helper methods to properly serialize Unity's curve types. Updated GetInfo to use these helpers for startLifetime, startSpeed, startSize, gravityModifier, and rateOverTime instead of only reading constant values.
* Use ctx param
* Update Server/src/services/tools/run_tests.py
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
* Minor fixes
* Rename anything EditorStateV2 to just EditorState
It's the default, there's no old version
* Make infer_single_instance_id public by removing underscore prefix
* Fix Python tests, again
* Replace AI generated .meta files with actual Unity ones
* ## Pre-Launch Enhancements: Testing Infrastructure & Tool Improvements (#8)
* Add local test harness for fast developer iteration
Scripts for running the NL/T/GO test suites locally against a GUI Unity
Editor, complementing the CI workflows in .github/workflows/.
Benefits:
- 10-100x faster than CI (no Docker startup)
- Real-time Unity console debugging
- Single test execution for rapid iteration
- Auto-detects HTTP vs stdio transport
Usage:
./scripts/local-test/setup.sh # One-time setup
./scripts/local-test/quick-test.sh NL-0 # Run single test
./scripts/local-test/run-nl-suite-local.sh # Full suite
See scripts/local-test/README.md for details.
Also updated .gitignore to:
- Allow scripts/local-test/ to be tracked
- Ignore generated artifacts (reports/*.xml, .claude/local/, .unity-mcp/)
* Fix issue #525: Save dirty scenes for all test modes
Move SaveDirtyScenesIfNeeded() call outside the PlayMode conditional
so EditMode tests don't get blocked by Unity's "Save Scene" modal dialog.
This prevents MCP from timing out when running EditMode tests with unsaved
scene changes.
* fix: add missing FAST_FAIL_TIMEOUT constant in PluginHub
The FAST_FAIL_TIMEOUT class attribute was referenced on line 149 but never
defined, causing AttributeError on every ping attempt. This error was silently
caught by the broad 'except Exception' handler, causing all fast-fail commands
(read_console, get_editor_state, ping) to fail after 6 seconds of retries with
'ping not answered' error.
Added FAST_FAIL_TIMEOUT = 10 to define a 10-second timeout for fast-fail
commands, matching the intent of the existing fast-fail infrastructure.
* feat(ScriptableObject): enhance dry-run validation for AnimationCurve and Quaternion
Dry-run validation now validates value formats, not just property existence:
- AnimationCurve: Validates structure ({keys:[...]} or direct array), checks
each keyframe is an object, validates numeric fields (time, value, inSlope,
outSlope, inWeight, outWeight) and integer fields (weightedMode)
- Quaternion: Validates array length (3 for Euler, 4 for raw) or object
structure ({x,y,z,w} or {euler:[x,y,z]}), ensures all components are numeric
Refactored shared validation helpers into appropriate locations:
- ParamCoercion: IsNumericToken, ValidateNumericField, ValidateIntegerField
- VectorParsing: ValidateAnimationCurveFormat, ValidateQuaternionFormat
Added comprehensive XML documentation clarifying keyframe field defaults
(all default to 0 except as noted).
Added 5 new dry-run validation tests covering valid and invalid formats
for both AnimationCurve and Quaternion properties.
* test: fix integration tests after merge
- test_refresh_unity_retry_recovery: Mock now handles both refresh_unity and
get_editor_state commands (refresh_unity internally calls get_editor_state
when wait_for_ready=True)
- test_run_tests_async_forwards_params: Mock response now includes required
'mode' field for RunTestsStartResponse Pydantic validation
- test_get_test_job_forwards_job_id: Updated to handle GetTestJobResponse as
Pydantic model instead of dict (use model_dump() for assertions)
* Update warning message to apply to all test modes
Follow-up to PR #527: Since SaveDirtyScenesIfNeeded() now runs for all test modes, update the warning message to say 'tests' instead of 'PlayMode tests'.
* feat(run_tests): add wait_timeout to get_test_job to avoid client loop detection
When polling for test completion, MCP clients like Cursor can detect the
repeated get_test_job calls as 'looping' and terminate the agent.
Added wait_timeout parameter that makes the server wait internally for tests
to complete (polling Unity every 2s) before returning. This dramatically
reduces client-side tool calls from 10-20 down to 1-2, avoiding loop detection.
Usage: get_test_job(job_id='xxx', wait_timeout=30)
- Returns immediately if tests complete within timeout
- Returns current status if timeout expires (client can call again)
- Recommended: 30-60 seconds
* fix: use Pydantic attribute access in test_run_tests_async for merge compatibility
* revert: remove local test harness - will be submitted in separate PR
---------
Co-authored-by: Scott Jennings <scott.jennings+CIGINT@cloudimperiumgames.com>
---------
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
Co-authored-by: dsarno <david@lighthaus.us>
Co-authored-by: Scott Jennings <scott.jennings+CIGINT@cloudimperiumgames.com>
* Add editor readiness v2, refresh tool, and preflight guards
* Detect external package changes and harden refresh retry
* feat: add TestRunnerNoThrottle and async test running with background stall prevention
- Add TestRunnerNoThrottle.cs: Sets editor to 'No Throttling' mode during test runs
with SessionState persistence across domain reload
- Add run_tests_async and get_test_job tools for non-blocking test execution
- Add TestJobManager for async test job tracking with progress monitoring
- Add ForceSynchronousImport to all AssetDatabase.Refresh() calls to prevent stalls
- Mark DomainReloadResilienceTests as [Explicit] with documentation explaining
the test infrastructure limitation (internal coroutine waits vs MCP socket polling)
- MCP workflow is unaffected - socket messages provide external stimulus that
keeps Unity responsive even when backgrounded
* refactor: simplify and clean up code
- Remove unused Newtonsoft.Json.Linq import from TestJobManager
- Add throttling to SessionState persistence (once per second) to reduce overhead
- Critical job state changes (start/finish) still persist immediately
- Fix duplicate XML summary tag in DomainReloadResilienceTests
* docs: add async test tools to README, document domain reload limitation
- Add run_tests_async and get_test_job to main README tools list
- Document background stall limitation for domain reload tests in DEV readme
* ci: add separate job for domain reload tests
Run [Explicit] domain_reload tests in their own job using -testCategory
* ci: run domain reload tests in same job as regular tests
Combines into single job with two test steps to reuse cached Library
* fix: address coderabbit review issues
- Fix TOCTOU race in TestJobManager.StartJob (single lock scope for check-and-set)
- Store TestRunnerApi reference with HideAndDontSave to prevent GC/serialization issues
* docs: update tool descriptions to prefer run_tests_async
- run_tests_async is now marked as preferred for long-running suites
- run_tests description notes it blocks and suggests async alternative
* docs: update README screenshot to v8.6 UI
* docs: add v8.6 UI screenshot
* Update README for MCP version and instructions for v8.7
* fix: handle preflight busy signals and derive job status from test results
- manage_asset, manage_gameobject, manage_scene now check preflight return
value and propagate busy/retry signals to clients (fixes Sourcery #1)
- TestJobManager.FinalizeCurrentJobFromRunFinished now sets job status to
Failed when resultPayload.Failed > 0, not always Succeeded (fixes Sourcery #2)
* fix: increase HTTP server startup timeout for dev mode
When 'Force fresh server install' is enabled, uvx uses --no-cache --refresh
which rebuilds the package and takes significantly longer to start.
- Increase timeout from 10s to 45s when dev mode is enabled
- Add informative log message explaining the longer startup time
- Show actual timeout value in warning message
* fix: derive job status from test results in FinalizeFromTask fallback
Apply same logic as FinalizeCurrentJobFromRunFinished: check result.Failed > 0
to correctly mark jobs as Failed when tests fail, even in the fallback path
when RunFinished callback is not delivered.
dsarno
Marcus Sanatan