Mark copilot-sdk mode as stable

.github/aw/syntax-agentic.md

@@ -300,7 +300,7 @@ description: Agentic workflow specific frontmatter fields for GitHub Agentic Wor
   - **`antigravity` engine** (experimental): Google Antigravity CLI in headless mode. Requires `ANTIGRAVITY_API_KEY` secret; model via `model:` (maps to `ANTIGRAVITY_MODEL`). Supports `max-turns`, tools allow-list, AWF firewall, and LLM gateway. Does not support `web-search`, `max-continuations`, or native agent files (agent content is prepended to the prompt).
   - **`opencode` engine** (experimental): Provider-agnostic, open-source AI coding agent (BYOK). Defaults to Copilot routing via `COPILOT_GITHUB_TOKEN` (or `${{ github.token }}` with `copilot-requests` feature). Supports 75+ models via `provider/model` format. Supports AWF firewall and LLM gateway.
   - **`engine.driver:`** — canonical field to run a custom inner driver script instead of the engine's built-in CLI. For the `pi` engine it launches the driver directly with Node.js (e.g. built-in `pi_agent_core_driver.cjs`, or a workspace-relative path like `.github/drivers/pi_agent_core_driver_sample_node.cjs`); the driver must emit JSONL compatible with `parse_pi_log.cjs` so step summaries and token tracking keep working. Accepts a bare basename (resolved from the setup-action directory) or a workspace-relative path; no absolute paths, no `..`, only `.js`/`.cjs`/`.mjs` (pi).
-  - **`copilot-sdk` / `engine.driver`** (experimental, copilot only): set `copilot-sdk: true` to start a headless Copilot CLI SDK sidecar. Set `driver: <path-or-command>` on the copilot engine to supply a custom SDK driver (`.js`/`.cjs`/`.mjs`/`.py`/`.ts`/`.mts`/`.rb`, or a bare PATH command); this also enables `copilot-sdk: true` automatically. Tune the repeated-tool-denial safeguard with the top-level `max-tool-denials:` field (default `5`).
+  - **`copilot-sdk`** (copilot only): set `copilot-sdk: true` to start a headless Copilot CLI SDK sidecar. **`engine.driver`** (experimental, copilot only): set `driver: <path-or-command>` to supply a custom SDK driver (`.js`/`.cjs`/`.mjs`/`.py`/`.ts`/`.mts`/`.rb`, or a bare PATH command); this also enables `copilot-sdk: true` automatically. Tune the repeated-tool-denial safeguard with the top-level `max-tool-denials:` field (default `5`).
 
     **Inline driver source** (copilot engine only): instead of pointing to a checked-in file, you can embed the driver source directly in the frontmatter using an object with exactly one runtime key (`node`, `python`, `go`, or `java`). The compiler materializes the source under `.gh-aw/copilot-sdk/` at runtime and generates a launcher wrapper. The required SDK package is installed automatically.
 

docs/src/content/docs/reference/engines.md

@@ -14,6 +14,7 @@ Set `engine:` in your workflow frontmatter and configure the corresponding secre
 | Engine | `engine:` value | Required Secret |
 |--------|-----------------|-----------------|
 | [GitHub Copilot CLI](https://docs.github.com/en/copilot/how-tos/use-copilot-agents/use-copilot-cli) (default) | `copilot` | [`copilot-requests: write`](/gh-aw/reference/auth/#copilot-requests-write-permission) (recommended) or [`COPILOT_GITHUB_TOKEN`](/gh-aw/reference/auth/#copilot_github_token) |
+| [GitHub Copilot (SDK mode)](/gh-aw/reference/engines/#copilot-sdk-support) | `copilot` + `copilot-sdk: true` | same as Copilot CLI |
 | [Claude by Anthropic (Claude Code)](https://www.anthropic.com/index/claude) | `claude` | [`ANTHROPIC_API_KEY`](/gh-aw/reference/auth/#anthropic_api_key) (standard) or [`engine.auth` Anthropic WIF](/gh-aw/reference/auth/#anthropic-workload-identity-federation-wif) (keyless) |
 | [OpenAI Codex](https://openai.com/blog/openai-codex) | `codex` | [OPENAI_API_KEY](/gh-aw/reference/auth/#openai_api_key) |
 | [Google Gemini CLI](https://github.com/google-gemini/gemini-cli) | `gemini` | [`GEMINI_API_KEY`](/gh-aw/reference/auth/#gemini_api_key) (standard) or [`engine.auth` Google WIF](/gh-aw/reference/auth/#google-workload-identity-federation-wif) (keyless) |

docs/src/content/docs/reference/frontmatter-full.md

@@ -2528,7 +2528,7 @@ engine:
     # (optional)
     tool-timeout: "example-value"
 
-  # Enables the experimental GitHub Copilot SDK integration (copilot engine only).
+  # Enables the GitHub Copilot SDK integration (copilot engine only).
   # When true, the harness starts a separate headless Copilot CLI sidecar on the
   # configured localhost port and sets COPILOT_SDK_URI on child processes.
   # (optional)

pkg/workflow/README.md

@@ -147,7 +147,7 @@ The `checkout:` frontmatter key is parsed by `ParseCheckoutConfigs` into one or
 | `UserAgent` | `string` | `engine.user-agent` | Custom user-agent string |
 | `Command` | `string` | `engine.command` | Custom executable path; skips installation steps when set |
 | `HarnessScript` | `string` | `engine.harness-script` | Custom Node.js harness script filename (replaces engine default) |
-| `CopilotSDK` | `bool` | `engine.copilot-sdk` | **(Experimental)** Enables GitHub Copilot SDK integration. When `true`, the compiler starts a headless Copilot CLI sidecar and sets `COPILOT_SDK_URI` on child processes so the SDK can connect to it. Also enabled automatically for the copilot engine when `Driver` is non-empty. |
+| `CopilotSDK` | `bool` | `engine.copilot-sdk` | Enables GitHub Copilot SDK integration. When `true`, the compiler starts a headless Copilot CLI sidecar and sets `COPILOT_SDK_URI` on child processes so the SDK can connect to it. Also enabled automatically for the copilot engine when `Driver` is non-empty. |
 | `Driver` | `string` | `engine.driver` | **(Experimental)** Custom driver script filename or command. Supports `.js`/`.cjs`/`.mjs` (Node.js), `.py` (Python), `.ts`/`.mts` (TypeScript), `.rb` (Ruby), or a bare command name for an arbitrary executable on `PATH`. Setting this field implies `copilot-sdk: true` for the copilot engine. |
 | `Env` | `map[string]string` | `engine.env` | Extra environment variables injected into the agent job |
 | `Auth` | `*EngineAuthConfig` | `engine.auth` | Engine-level auth config for the API proxy sidecar |

pkg/workflow/compiler_validators.go

@@ -329,7 +329,6 @@ func (c *Compiler) emitExperimentalFeatureWarnings(workflowData *WorkflowData) {
 		{enabled: workflowData.SafeOutputs != nil && workflowData.SafeOutputs.DispatchRepository != nil, message: "Using experimental feature: dispatch-repository"},
 		{enabled: workflowData.SafeOutputs != nil && workflowData.SafeOutputs.MergePullRequest != nil, message: "Using experimental feature: merge-pull-request"},
 		{enabled: workflowData.SafeOutputs != nil && workflowData.SafeOutputs.ReplaceLabel != nil, message: "Using experimental feature: replace-label"},
-		{enabled: workflowData.EngineConfig != nil && workflowData.EngineConfig.CopilotSDK, message: "Using experimental feature: engine.copilot-sdk"},
 		{enabled: isFeatureEnabled(constants.GHAWDetectionFeatureFlag, workflowData), message: "Using experimental feature: gh-aw-detection"},
 		{enabled: len(workflowData.LSP) > 0, message: "Using experimental feature: lsp"},
 	}

pkg/workflow/copilot_sdk_experimental_warning_test.go

@@ -13,14 +13,16 @@ import (
 	"github.com/github/gh-aw/pkg/testutil"
 )
 
-func TestCopilotSDKExperimentalWarning(t *testing.T) {
+// TestCopilotSDKNoExperimentalWarning tests that the copilot-sdk feature
+// does not emit an experimental warning, as the feature is no longer
+// considered experimental.
+func TestCopilotSDKNoExperimentalWarning(t *testing.T) {
 	tests := []struct {
-		name          string
-		content       string
-		expectWarning bool
+		name    string
+		content string
 	}{
 		{
-			name: "copilot-sdk enabled produces experimental warning",
+			name: "copilot-sdk enabled does not produce experimental warning",
 			content: `---
 on: workflow_dispatch
 engine:
@@ -32,7 +34,6 @@ permissions:
 
 # Test Workflow
 `,
-			expectWarning: true,
 		},
 		{
 			name: "copilot-sdk disabled does not produce experimental warning",
@@ -47,7 +48,6 @@ permissions:
 
 # Test Workflow
 `,
-			expectWarning: false,
 		},
 		{
 			name: "no copilot-sdk does not produce experimental warning",
@@ -60,7 +60,6 @@ permissions:
 
 # Test Workflow
 `,
-			expectWarning: false,
 		},
 	}
 
@@ -73,6 +72,7 @@ permissions:
 				t.Fatal(err)
 			}
 
+			// Capture stderr to check for warnings
 			oldStderr := os.Stderr
 			r, w, _ := os.Pipe()
 			os.Stderr = w
@@ -81,6 +81,7 @@ permissions:
 			compiler.SetStrictMode(false)
 			err := compiler.CompileWorkflow(testFile)
 
+			// Restore stderr
 			w.Close()
 			os.Stderr = oldStderr
 			var buf bytes.Buffer
@@ -92,20 +93,9 @@ permissions:
 				return
 			}
 
-			expectedMessage := "Using experimental feature: engine.copilot-sdk"
-
-			if tt.expectWarning {
-				if !strings.Contains(stderrOutput, expectedMessage) {
-					t.Errorf("Expected warning containing '%s', got stderr:\n%s", expectedMessage, stderrOutput)
-				}
-				if compiler.GetWarningCount() == 0 {
-					t.Error("Expected warning count > 0 but got 0")
-				}
-				return
-			}
-
-			if strings.Contains(stderrOutput, expectedMessage) {
-				t.Errorf("Did not expect warning '%s', but got stderr:\n%s", expectedMessage, stderrOutput)
+			unexpectedMessage := "Using experimental feature: engine.copilot-sdk"
+			if strings.Contains(stderrOutput, unexpectedMessage) {
+				t.Errorf("Did not expect experimental warning '%s', but got stderr:\n%s", unexpectedMessage, stderrOutput)
 			}
 		})
 	}