feat(copilot): make cloud coding-agent files opt-in

.changeset/copilot-cloud-opt-in.md

@@ -0,0 +1,9 @@
+---
+"@fission-ai/openspec": minor
+---
+
+Make GitHub Copilot cloud coding-agent files opt-in. Selecting the `github-copilot` tool no longer silently writes a GitHub Actions workflow into `.github/`; `openspec init` now asks first (default No) and remembers the choice in `openspec/config.yaml` (`githubCopilot.cloudAgent`). Use `--copilot-cloud` / `--no-copilot-cloud` to decide non-interactively.
+
+- `openspec update` never prompts — it only refreshes cloud files for projects that opted in (or that already have generated cloud files, so existing setups keep working).
+- Opting out (`--no-copilot-cloud` or `cloudAgent: false`) removes OpenSpec-managed cloud files; a user-customized file is always preserved, never overwritten or deleted.
+- `init` and `update` now report whether cloud files were written, skipped, or left untouched — and if you already have your own `copilot-setup-steps.yml`, they say it was preserved and that you need to add the OpenSpec install step by hand.

docs/cli.md

@@ -102,6 +102,8 @@ openspec init [path] [options]
 | `--force` | Auto-cleanup legacy files without prompting |
 | `--profile <profile>` | Override global profile for this init run (`core` or `custom`) |
 | `--no-animation` | Show a static welcome screen instead of the animated one |
+| `--copilot-cloud` | Set up GitHub Copilot [cloud coding-agent files](supported-tools.md#github-copilot-cloud-coding-agent) without prompting |
+| `--no-copilot-cloud` | Skip GitHub Copilot cloud coding-agent files without prompting |
 
 `--profile custom` uses whatever workflows are currently selected in global config (`openspec config profile`).
 

docs/customization.md

@@ -18,6 +18,7 @@ The `openspec/config.yaml` file is the easiest way to customize OpenSpec for you
 - **Inject project context** - AI sees your tech stack, conventions, etc.
 - **Add per-artifact rules** - Custom rules for specific artifacts
 - **Add per-operation guidance** - Advisory preferences for apply and archive work
+- **Remember integration choices** - e.g. the [GitHub Copilot cloud coding agent](supported-tools.md#github-copilot-cloud-coding-agent) opt-in
 
 ### Quick Setup
 
@@ -52,6 +53,11 @@ operations:
   archive:
     guidance:
       - Keep the completion summary concise
+
+# Set by `openspec init` when you choose (or decline) the GitHub Copilot
+# cloud coding agent; controls whether `init`/`update` generate its files.
+githubCopilot:
+  cloudAgent: false
 ```
 
 ### How It Works

docs/supported-tools.md

@@ -102,7 +102,7 @@ to read the hint.
 | ZCode (`zcode`) | `.zcode/skills/openspec-*/SKILL.md` | `.zcode/commands/opsx/<id>.md` |
 | Shared `.agents` skills (`agents`) | `.agents/skills/openspec-*/SKILL.md` | Not generated (no command adapter; use skill-based `/openspec-*` invocations) |
 
-\*\* GitHub Copilot prompt files are recognized as custom slash commands in IDE extensions (VS Code, JetBrains, Visual Studio). Copilot CLI does not currently consume `.github/prompts/*.prompt.md` directly.
+\*\* GitHub Copilot prompt files are recognized as custom slash commands in IDE extensions (VS Code, JetBrains, Visual Studio). Copilot CLI does not currently consume `.github/prompts/*.prompt.md` directly. Selecting `github-copilot` can also set up the GitHub-hosted **cloud coding agent** — see [GitHub Copilot cloud coding agent](#github-copilot-cloud-coding-agent) below.
 
 \*\*\* Hermes loads skills from `~/.hermes/skills/` by default. To use project-local OpenSpec skills, add the project `.hermes/skills/` directory to `skills.external_dirs` in `~/.hermes/config.yaml`; Hermes then exposes skills with user-facing slash invocations such as `/openspec-propose`.
 
@@ -114,6 +114,24 @@ repo-local `.minimax` or `.mavis` directories. Commands-only delivery leaves
 existing global MiniMax Code skills untouched so one project's delivery setting
 cannot remove skills used by another project.
 
+### GitHub Copilot cloud coding agent
+
+GitHub's [Copilot coding agent](https://docs.github.com/en/copilot/using-github-copilot/coding-agent) runs on GitHub in a GitHub Actions environment — separate from Copilot in your editor. OpenSpec can set it up to use the OpenSpec CLI by generating two files:
+
+- `.github/workflows/copilot-setup-steps.yml` — installs `@fission-ai/openspec` in the agent's environment
+- `.github/agents/openspec.agent.md` — tells the agent how to drive OpenSpec
+
+Because this writes a GitHub Actions workflow into your repository, it is **opt-in**:
+
+| How | Behavior |
+|-----|----------|
+| `openspec init` (interactive) | Asks whether to set up cloud files. Default is **No**. |
+| `openspec init --copilot-cloud` | Sets them up without prompting (for scripts/CI). |
+| `openspec init --no-copilot-cloud` | Skips them without prompting, and removes any previously generated ones. |
+| `openspec update` | Never prompts. Refreshes the files only if you opted in (or the project already has them). If you opted out, it removes OpenSpec-managed cloud files. |
+
+Your choice is saved in `openspec/config.yaml` as `githubCopilot.cloudAgent: true|false`, so non-interactive updates honor it. OpenSpec only ever writes or removes files whose content it generated — if you customize `copilot-setup-steps.yml` or `openspec.agent.md`, or already have your own, it is left untouched (and `init`/`update` tell you so).
+
 ### When to pick the shared `.agents` target
 
 `agents` is the vendor-neutral option: it writes skills to `.agents/skills/`, the

src/cli/index.ts

@@ -161,7 +161,9 @@ program
   .option('--force', 'Auto-cleanup legacy files without prompting')
   .option('--profile <profile>', 'Override global config profile (core or custom)')
   .option('--no-animation', 'Show a static welcome screen instead of the animated one')
-  .action(async (targetPath = '.', options?: { tools?: string; force?: boolean; profile?: string; animation?: boolean }) => {
+  .option('--copilot-cloud', 'Set up GitHub Copilot cloud coding-agent files without prompting')
+  .option('--no-copilot-cloud', 'Skip GitHub Copilot cloud coding-agent files without prompting')
+  .action(async (targetPath = '.', options?: { tools?: string; force?: boolean; profile?: string; animation?: boolean; copilotCloud?: boolean }) => {
     try {
       // Validate that the path is a valid directory
       const resolvedPath = path.resolve(targetPath);
@@ -188,6 +190,7 @@ program
         force: options?.force,
         profile: options?.profile,
         animation: options?.animation,
+        copilotCloud: options?.copilotCloud,
       });
       await initCommand.execute(targetPath);
     } catch (error) {

src/core/completions/command-registry.ts

@@ -27,6 +27,14 @@ export const COMMAND_REGISTRY: CommandDefinition[] = [
         name: 'no-animation',
         description: 'Show a static welcome screen instead of the animated one',
       },
+      {
+        name: 'copilot-cloud',
+        description: 'Generate GitHub Copilot cloud coding-agent files (opt-in; default: prompt)',
+      },
+      {
+        name: 'no-copilot-cloud',
+        description: 'Skip generating GitHub Copilot cloud coding-agent files',
+      },
     ],
   },
   {

src/core/github-copilot/cloud-agent.ts

@@ -9,7 +9,9 @@
 
 import path from 'path';
 import { promises as fs } from 'fs';
+import { Document, parseDocument, isMap } from 'yaml';
 import { FileSystemUtils } from '../../utils/file-system.js';
+import { readProjectConfig, resolveConfigFilePath } from '../project-config.js';
 
 const COPILOT_TOOL_ID = 'github-copilot';
 const OPENSPEC_MANAGED_MARKER = 'Generated by OpenSpec for GitHub Copilot coding agent support.';
@@ -482,3 +484,135 @@ export async function removeCopilotCloudFiles(projectPath: string): Promise<numb
 
   return removed;
 }
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Opt-in
+//
+// Generating a GitHub Actions workflow into a user's `.github/` is invasive and
+// ties us to Copilot's externally-owned coding-agent format, so cloud files are
+// opt-in rather than an automatic side effect of selecting the Copilot tool.
+// The decision is persisted in openspec/config.yaml so non-interactive
+// `openspec update` (CI, agents) honors it without ever prompting.
+// ─────────────────────────────────────────────────────────────────────────────
+
+const COPILOT_CONFIG_KEY = 'githubCopilot';
+const COPILOT_CLOUD_AGENT_KEY = 'cloudAgent';
+
+/**
+ * Read the persisted opt-in for Copilot cloud-file generation.
+ *
+ * Tri-state: `true` (opted in), `false` (explicitly opted out), or `undefined`
+ * (never decided). A malformed value is treated as undecided rather than an
+ * error, matching how {@link readProjectConfig} degrades on bad fields.
+ */
+export function readCopilotCloudOptIn(projectPath: string): boolean | undefined {
+  const value = readProjectConfig(projectPath)?.githubCopilot?.cloudAgent;
+  return typeof value === 'boolean' ? value : undefined;
+}
+
+/**
+ * True when a managed Copilot cloud file (the current generation or a
+ * recognized legacy one) already exists. Projects created before the opt-in
+ * prompt existed are treated as implicitly opted in, so `openspec update`
+ * keeps their files current instead of silently abandoning them.
+ */
+export async function hasExistingManagedCloudFiles(projectPath: string): Promise<boolean> {
+  for (const relPath of Object.values(COPILOT_CLOUD_FILES)) {
+    const fullPath = FileSystemUtils.resolveProjectArtifactPath(projectPath, relPath);
+    if (!(await FileSystemUtils.fileExists(fullPath))) {
+      continue;
+    }
+    const content = await FileSystemUtils.readFile(fullPath);
+    if (isManagedCopilotCloudFile(relPath, content)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/**
+ * Effective decision on whether to generate/refresh Copilot cloud files.
+ * An explicit opt-in or opt-out always wins; when undecided, fall back to
+ * whether managed files already exist (the migration path above).
+ */
+export async function isCopilotCloudEnabled(projectPath: string): Promise<boolean> {
+  const optIn = readCopilotCloudOptIn(projectPath);
+  if (typeof optIn === 'boolean') {
+    return optIn;
+  }
+  return hasExistingManagedCloudFiles(projectPath);
+}
+
+/**
+ * Persist the Copilot cloud opt-in into openspec/config.yaml.
+ *
+ * Uses the YAML document model rather than a re-serialize so the user's
+ * existing comments, ordering, and formatting survive untouched — the config
+ * file is hand-authored and heavily commented, so a lossy round-trip would be
+ * its own source of toil. No-op when no config file exists yet (init creates it
+ * before this is called); the caller treats persistence failures as non-fatal.
+ */
+export async function persistCopilotCloudOptIn(
+  projectPath: string,
+  value: boolean
+): Promise<void> {
+  const configPath = resolveConfigFilePath(projectPath);
+  if (!configPath) {
+    return;
+  }
+  const existing = await FileSystemUtils.readFile(configPath);
+  const parsed = parseDocument(existing);
+  // `setIn(['githubCopilot', ...])` needs a top-level map. A config whose root
+  // is anything else — a scalar (`null`, a bare string) or even a sequence —
+  // has no map to set a key on and makes setIn throw. Such a file is already
+  // invalid (readProjectConfig rejects it), so start fresh rather than crash.
+  // An empty or comment-only file parses to null contents, which setIn fills in
+  // while keeping the comments — so only a non-map root is discarded.
+  const doc: Document =
+    parsed.contents === null || isMap(parsed.contents) ? parsed : new Document();
+  doc.setIn([COPILOT_CONFIG_KEY, COPILOT_CLOUD_AGENT_KEY], value);
+  await FileSystemUtils.writeFile(configPath, doc.toString());
+}
+
+/**
+ * Return the managed cloud-file paths (relative to the project root) that
+ * currently hold user-owned, non-managed content — i.e. files OpenSpec will
+ * deliberately leave untouched. Used to tell an opted-in user that we preserved
+ * their existing file rather than silently doing nothing, which is the honest
+ * answer to "will this affect my existing Copilot cloud setup?".
+ */
+export async function findUnmanagedCloudFiles(projectPath: string): Promise<string[]> {
+  const collisions: string[] = [];
+  for (const relPath of Object.values(COPILOT_CLOUD_FILES)) {
+    const fullPath = FileSystemUtils.resolveProjectArtifactPath(projectPath, relPath);
+    if (!(await FileSystemUtils.fileExists(fullPath))) {
+      continue;
+    }
+    const content = await FileSystemUtils.readFile(fullPath);
+    if (!isManagedCopilotCloudFile(relPath, content)) {
+      collisions.push(relPath);
+    }
+  }
+  return collisions;
+}
+
+/**
+ * Return the managed cloud-file paths (relative to the project root) that
+ * currently exist and hold OpenSpec-generated content. Callers report this
+ * rather than the intended paths, so output never claims a file that a write
+ * skipped (user already owns it) or that reconciliation removed.
+ */
+export async function listManagedCloudFiles(projectPath: string): Promise<string[]> {
+  const present: string[] = [];
+  for (const relPath of Object.values(COPILOT_CLOUD_FILES)) {
+    const fullPath = FileSystemUtils.resolveProjectArtifactPath(projectPath, relPath);
+    if (!(await FileSystemUtils.fileExists(fullPath))) {
+      continue;
+    }
+    const content = await FileSystemUtils.readFile(fullPath);
+    if (isManagedCopilotCloudFile(relPath, content)) {
+      present.push(relPath);
+    }
+  }
+  return present;
+}