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unity-pipeline

Drives a running Unity Editor or dev Player through the unity-pipeline package — recompile, run tests, run C# scripts, method-reload code at runtime and audit the project. Use when an agent must control a live Unity instance or automate its tests.

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Unity-Technologies/skills
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October 8, 2026 at 17:43
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unity-pipeline
description
Drives a running Unity Editor or dev Player through the unity-pipeline package — recompile, run tests, run C# scripts, method-reload code at runtime and audit the project. Use when an agent must control a live Unity instance or automate its tests.
# Unity Pipeline (agent control) Invoke commands with `unity command <name> [args]`. Run `unity command` with no name to list what an instance exposes. Two servers exist: **Editor** (`7800-7849`, auto-starts with the editor) and **Runtime** (`7900-7949`, only in a dev Player build). `unity command --query <term>` filters that list by name, description or tag. ## 1. Install & verify ```bash unity pipeline install # install into current project (or --project-path) unity pipeline list # confirm the editor instance + server are reachable unity status --until-ready # wait until the editor server is ready unity command editor_status # confirm the editor server answers ``` An Editor that was already open picks up the package only on its next refresh, usually when its window regains focus. Until then `unity status` reports `STATUS_PIPELINE_LOAD_PENDING`; if that persists, ask the user to switch to the Unity Editor window, then re-run `unity status --until-ready`. ## 2. Autonomous edit loop (Editor) This is the core agent workflow: keep the editor alive, change code, recompile, test. ```bash # 1. Keep the editor ticking even when unfocused/minimized. REQUIRED before headless work — # Unity otherwise throttles or stalls update/compile when it isn't the active app. unity command set_autotick --enable true # 2. Edit C# source files on disk normally. # 3. Recompile (async: triggers a domain reload, then poll until done). unity command recompile unity command recompile_status # repeat until "completed" or "up_to_date" # Tolerate connection errors while the domain reload is in flight — that is expected. # If recompile_status reports failed=true, read its "errors" array and fix before testing. # 4. (Optional) List available tests without running them. unity command list_tests --mode editor # mode: all | editor | playmode # 5. Run tests (filter to keep it fast). unity command run_tests --mode editor --filter MyFixture.MyTest ``` `run_tests` modes: `all` | `editor` | `playmode`. `filter_type`: `testName` | `assembly` | `category`. For long runs use `--async_tests true` and poll `unity command test_status` (abort with `unity command cancel_tests`). > **Known caveat:** when any selected test *fails*, `run_tests` may surface an opaque > result instead of the failure details. Re-run a narrower `--filter`, or inspect the > editor's Test Runner / logs to get the real failure. **Reading exit codes.** They separate "rewrite the invocation" from "the Editor failed", which is the distinction this loop depends on: | Exit | Meaning | What to do | |------|---------|------------| | `2` | Bad arguments — a misspelled flag, a wrong type, too many positionals. Nothing ran. | Fix the command line and retry. The error names the problem and often suggests the right flag. | | `6` | The command ran and failed, or no Editor could be reached. | Read the error. If it says no Pipeline instance was found, the Editor isn't reachable: wait with `unity status --until-ready` (or check `unity pipeline list` for Safe Mode), then retry. Otherwise retrying the same invocation will not help. | Do not retry an exit 2 unchanged, and do not rewrite a command line on an exit 6. ## 3. Runtime method reload Change gameplay code in a **running** game with no domain reload. The game must be live: enter Editor Play Mode (`unity command editor_play`) or run a dev Player. The runtime Pipeline driver (enabled via Project Settings > Pipeline > Runtime) auto-discovers tagged methods on `Awake` (no manual registration). Mono only — Editor Play Mode and Mono desktop dev builds, not IL2CPP. The token is auto-injected for local requests. ### `reload_file` Edit the method body directly; no separate file, no boilerplate. 1. **Before entering Play Mode**, tag the method `[MethodReload]` on the MonoBehaviour and recompile. The reload hook is compiled into the method, so tagging it while the game runs has no effect: exit Play Mode, recompile, and enter it again. 2. With the game running, edit the method body on disk. 3. Apply (re-run to iterate): ```bash unity command reload_file --filename Assets/Spinner.cs ``` Add `--pdb` to make it debuggable — emits a portable PDB mapped to your source so breakpoints in the original file bind (attach the IDE + enable Editor Attaching; compiles unoptimized): ```bash unity command reload_file --filename Assets/Spinner.cs --pdb ``` Constraints: `void` instance methods only; **public** members only; debugging requires `--pdb` (the default emits no symbols). `unity command methodreload_status` shows active overrides. `reload_file` options: `--timeout <ms>` (default 30000), `--assemblyDir <dir>` (persist DLLs instead of in-memory); `cleanup_methodreload --assemblyDir <dir>` clears old DLLs. The CLI consumes `--timeout` itself, in seconds. To pass the package's `--timeout`, put the command's arguments after `--`: ```bash unity command reload_file -- --filename Assets/Spinner.cs --timeout 60000 ``` ## 4. Bulk construction: `run_script` (the builder pattern) For bulk work — creating many objects, wiring fields, generating content — put the code in a **versioned project script** and run a named static entry point with `run_script`. No domain reload, no code carried through the protocol; iterating costs an in-memory compile (< ~2s), not a 15–20s recompile. ```bash # 1. Write the builder OUTSIDE Assets/ (so the write triggers no asset import / domain reload), # e.g. AgentScripts/Build.cs: public static class Build { public static int All() { ... } } # 2. Run it — relative paths resolve against the project root (the parent of Assets/): unity command run_script --file AgentScripts/Build.cs --entry Build.All # 3. Iterate: edit the file, re-run. Useful extras: unity command run_script --file AgentScripts/Build.cs --dry_run true # compile-only check: diagnostics, nothing loaded or executed unity command run_script --file AgentScripts/Build.cs --entry Build.All --args '[3, "Green"]' ``` Rules of thumb: - **Code goes in files on disk via `run_script`; `eval` is for genuinely ad-hoc one-liners.** Never ship multi-line escaped C# strings through `eval` — write the file, run the entry. - Compiles see the project's **active editor defines** (`UNITY_EDITOR`, version/platform symbols); `--defines` appends extra symbols on top. - Entry points may be `async Task`/`Task<T>` — they are awaited asynchronously (the editor keeps pumping, so awaits resuming on Unity's context work naturally) and `Task<T>.Result` is returned. The wait is bounded by `timeout_ms`; on expiry the task keeps running detached. - Runtime exceptions come back with `file:line` mapped to your source (a source-mapped PDB is always emitted for executing runs; they compile unoptimized). - `--mode hotpatch` instead applies `[MethodReload]` in-place method replacements (delegates to `reload_file`); `entry`/`args`/`dry_run` are rejected there and `references`/`defines` don't apply. ## 5. Quick C# eval (Editor or dev Player) For genuinely ad-hoc one-liners only — anything longer belongs in a file run via `run_script`. `eval` targets the Editor by default; add `--runtime <process name>` to run it in a dev Player. ```bash unity command eval "return 2 + 2;" unity command eval "return UnityEngine.Time.timeScale;" --runtime MyGame # Or evaluate a .cs file on disk. Keep it outside Assets/, where Unity would compile it as project source: unity command eval_file AgentScripts/Scratch.cs ``` ## 6. Project audit (Editor) Static-analysis scan via Project Auditor, producing a CSV of issues to fix. Trigger, poll, read. ```bash unity command audit # optional: --categories Code,ProjectSetting --output my.csv unity command audit_status # repeat until terminal status ``` `audit_status` is terminal on `completed` (with `csvPath` + `issueCount`), `failed`, `unavailable`, or `interrupted` (a domain reload killed the scan — just re-run `audit`). Polling stays responsive while a Code-category scan compiles assemblies and holds the main thread. One scan at a time: a second `audit` returns `busy`. There is no cancel — stop polling to abandon a scan. CSV columns: `Category, Severity, Areas, Description, RelativePath, Line, DescriptorId, Recommendation` (diagnostics only, so every row is something to fix; `Recommendation` says how). > **Requires Project Auditor plus its rules.** `unavailable` means the Editor has no Project Auditor, > or it has no analysis rules — in a built-in-module Editor the rules live in the separate > `com.unity.project-auditor-rules` package (`unity command package_add --identifier > com.unity.project-auditor-rules --confirm true`). Read the `message` field; the command never reports > an empty `completed` scan that would look like a clean project. ## Gotchas - **`set_autotick` first.** Without it, recompile and tests can hang while the editor is unfocused. The package's watchdog relies on the tick loop staying alive. - **A stuck command may mean a modal dialog is open**, not a hang — a dialog blocks the main thread until dismissed. If a command runs long, check `unity command editor_status` (answers instantly even when blocked); `status: "blocked_by_dialog"` means stop retrying and tell the human what's blocking (its `dialog.title`/`message`/`buttons`) — it can't be clicked over CLI. - **Method reload needs the game running.** `reload_file` applies to a live game — enter Editor Play Mode (`unity command editor_play`) first, or run a dev Player. - **Player-only commands need a dev Player.** `log`, `set_timescale`, `runtime_status`, etc. hit the Runtime server, which does not run in the Editor. - **Async commands poll.** `recompile`→`recompile_status`, `run_tests --async_tests`→ `test_status`. Never assume completion from the trigger call's response. - **Target a specific instance** when more than one is running: `--project-path <path>` selects an Editor, `--runtime <process name>` or `--runtime-path <port file>` selects a dev Player.
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