popemkt · popemkt · Apr 12, 2026 · Apr 21, 2026 · Apr 21, 2026 · Apr 21, 2026
diff --git a/.archon/workflows/e2e-copilot-smoke.yaml b/.archon/workflows/e2e-copilot-smoke.yaml
@@ -0,0 +1,26 @@
+# E2E smoke test — GitHub Copilot community provider
+# Verifies: provider registration, SDK session start, simple prompt response.
+# Auth: run `copilot login`, or provide COPILOT_GITHUB_TOKEN / GH_TOKEN / GITHUB_TOKEN.
+name: e2e-copilot-smoke
+description: 'Smoke test for the GitHub Copilot community provider.'
+provider: copilot
+model: gpt-5-mini
+
+nodes:
+  - id: simple
+    prompt: 'Reply with exactly COPILOT_OK'
+    idle_timeout: 30000
+
+  - id: assert
+    bash: |
+      output="$simple.output"
+      if [ -z "$output" ]; then
+        echo "FAIL: simple node returned empty output"
+        exit 1
+      fi
+      echo "$output" | rg -q "COPILOT_OK" || {
+        echo "FAIL: expected COPILOT_OK, got: $output"
+        exit 1
+      }
+      echo "PASS: simple=$output"
+    depends_on: [simple]
diff --git a/bun.lock b/bun.lock
diff --git a/packages/core/src/config/config-loader.ts b/packages/core/src/config/config-loader.ts
@@ -98,6 +98,7 @@ const SAFE_ASSISTANT_FIELDS: Record<string, readonly string[]> = {
   codex: ['model', 'modelReasoningEffort', 'webSearchMode'],
   // community providers — list each field we're confident is safe to
   // show in the web UI. Unknown providers fall through with no fields.
+  copilot: ['model'],
   pi: ['model'],
 };
 

diff --git a/packages/docs-web/src/content/docs/getting-started/ai-assistants.md b/packages/docs-web/src/content/docs/getting-started/ai-assistants.md
@@ -1,6 +1,6 @@
 ---
 title: AI Assistants
-description: Configure Claude Code, Codex, and Pi as AI assistants for Archon.
+description: Configure Claude Code, Codex, GitHub Copilot, and Pi as AI assistants for Archon.
 category: getting-started
 area: clients
 audience: [user]
@@ -9,7 +9,7 @@ sidebar:
   order: 4
 ---
 
-You must configure **at least one** AI assistant. All three can be configured and mixed within workflows.
+You must configure **at least one** AI assistant. All four can be configured and mixed within workflows.
 
 ## Claude Code
 
@@ -227,6 +227,80 @@ If you want Codex to be the default AI assistant for new conversations without c
 DEFAULT_AI_ASSISTANT=codex
 ```
 
+## GitHub Copilot (Community Provider)
+
+**SDK-backed community provider.** Archon's Copilot adapter uses `@github/copilot-sdk`, which drives the Copilot CLI over GitHub's supported JSON-RPC bridge instead of screen-scraping the interactive TUI.
+
+Copilot is registered as `builtIn: false` — like Pi, it is a bundled community provider rather than a core built-in.
+
+### Install
+
+For source installs, `bun install` pulls in the SDK and its bundled CLI dependency automatically.
+
+For compiled Archon binaries, install the Copilot CLI yourself and point Archon at it if needed:
+
+```bash
+# Any platform
+npm install -g @github/copilot
+```
+
+Optional override paths:
+
+```ini
+COPILOT_CLI_PATH=/absolute/path/to/copilot
+```
+
+```yaml
+assistants:
+  copilot:
+    copilotCliPath: /absolute/path/to/copilot
+```
+
+### Authenticate
+
+Copilot authentication is delegated to the Copilot CLI / SDK.
+
+Use one of:
+
+- `copilot login`
+- `COPILOT_GITHUB_TOKEN`
+- `GH_TOKEN`
+- `GITHUB_TOKEN`
+
+Request-scoped env vars still win, so codebase env overrides work the same way they do for the other providers.
+
+### Configuration Options
+
+```yaml
+assistants:
+  copilot:
+    model: gpt-5-mini
+    # Optional: explicit Copilot CLI path
+    # copilotCliPath: /absolute/path/to/copilot
+    # Optional: override Copilot config dir
+    # configDir: /absolute/path/to/copilot-config
+    # Optional: allow Copilot to auto-discover repo MCP/skills
+    # enableConfigDiscovery: false
+```
+
+> **⚠️ Trust boundary.** `enableConfigDiscovery: true` lets the Copilot CLI/SDK load repo-level config (e.g. `.mcp.json`, `.vscode/mcp.json`, skill directories) directly, bypassing Archon's workflow validation surface. Only enable it for repositories you trust. Archon's default (`false`) keeps MCP/skills under explicit workflow control via `nodeConfig.mcp` and `nodeConfig.skills`.
+
+### Supported Archon Features
+
+| Feature | Support | Notes |
+|---|---|---|
+| Session resume | ✅ | Returns `sessionId` and reuses it on resume |
+| Reasoning control | ✅ | `effort:` / string `thinking:` map to Copilot `reasoningEffort` |
+| System prompt override | ✅ | `systemPrompt:` |
+| Codebase env vars (`envInjection`) | ✅ | merged into the spawned Copilot CLI environment |
+| Tool restrictions | ✅ | `allowed_tools` → `availableTools`, `denied_tools` → `excludedTools` (SDK enforces `availableTools` precedence when both are set) |
+| MCP servers | ✅ | `mcp: path/to/servers.json` → `SessionConfig.mcpServers` (env vars `$FOO` expanded; missing vars warned) |
+| Skills | ✅ | `skills: [name]` resolved from `.agents/skills/`, `.claude/skills/` (project or home) → `SessionConfig.skillDirectories` |
+| Structured output | ✅ | best-effort: schema instruction appended to the prompt, assistant transcript parsed as JSON on completion (models that reliably follow instruction succeed; unparseable output degrades to the dag-executor's missing-output warning) |
+| Sub-agents (`agents:`) | ✅ | `name`/`description`/`prompt`/`tools` (allowlist) map 1:1 to `SessionConfig.customAgents`; Claude-specific fields (`model`, `disallowedTools`, `skills`, `maxTurns`) warn per agent and are ignored |
+| Fallback model | ❌ | not wired |
+| Sandbox | ❌ | Copilot permissions are separate from Archon's sandbox surface |
+
 ## Pi (Community Provider)
 
 **One adapter, ~20 LLM backends.** Pi (`@mariozechner/pi-coding-agent`) is a community-maintained coding-agent harness that Archon integrates as the first community provider. It unlocks Anthropic, OpenAI, Google (Gemini + Vertex), Groq, Mistral, Cerebras, xAI, OpenRouter, Hugging Face, and more under a single `provider: pi` entry.

diff --git a/packages/providers/package.json b/packages/providers/package.json
@@ -13,17 +13,19 @@
     "./codex/provider": "./src/codex/provider.ts",
     "./codex/config": "./src/codex/config.ts",
     "./codex/binary-resolver": "./src/codex/binary-resolver.ts",
+    "./community/copilot": "./src/community/copilot/index.ts",
     "./community/pi": "./src/community/pi/index.ts",
     "./errors": "./src/errors.ts",
     "./registry": "./src/registry.ts"
   },
   "scripts": {
-    "test": "bun test src/claude/provider.test.ts && bun test src/codex/provider.test.ts && bun test src/registry.test.ts && bun test src/codex/binary-guard.test.ts && bun test src/codex/binary-resolver.test.ts && bun test src/codex/binary-resolver-dev.test.ts && bun test src/claude/binary-resolver.test.ts && bun test src/claude/binary-resolver-dev.test.ts && bun test src/community/pi/model-ref.test.ts && bun test src/community/pi/config.test.ts && bun test src/community/pi/event-bridge.test.ts && bun test src/community/pi/options-translator.test.ts && bun test src/community/pi/session-resolver.test.ts && bun test src/community/pi/provider.test.ts",
+    "test": "bun test src/claude/provider.test.ts && bun test src/codex/provider.test.ts && bun test src/registry.test.ts && bun test src/codex/binary-guard.test.ts && bun test src/codex/binary-resolver.test.ts && bun test src/codex/binary-resolver-dev.test.ts && bun test src/claude/binary-resolver.test.ts && bun test src/claude/binary-resolver-dev.test.ts && bun test src/community/pi/model-ref.test.ts && bun test src/community/pi/config.test.ts && bun test src/community/pi/event-bridge.test.ts && bun test src/community/pi/options-translator.test.ts && bun test src/community/pi/session-resolver.test.ts && bun test src/community/pi/provider.test.ts && bun test src/community/copilot/config.test.ts && bun test src/community/copilot/binary-resolver.test.ts && bun test src/community/copilot/provider.test.ts && bun test src/community/copilot/tool-restrictions.test.ts && bun test src/community/copilot/mcp-translation.test.ts && bun test src/community/copilot/skills-translation.test.ts && bun test src/community/copilot/structured-output.test.ts && bun test src/community/copilot/provider-hardening.test.ts && bun test src/community/copilot/agents-translation.test.ts",
     "type-check": "bun x tsc --noEmit"
   },
   "dependencies": {
     "@anthropic-ai/claude-agent-sdk": "^0.2.89",
     "@archon/paths": "workspace:*",
+    "@github/copilot-sdk": "^0.2.2",
     "@mariozechner/pi-ai": "^0.67.5",
     "@mariozechner/pi-coding-agent": "^0.67.5",
     "@openai/codex-sdk": "^0.116.0",