feat(init): add Amp skills support

.changeset/calm-amps-work.md

@@ -0,0 +1,7 @@
+---
+"@fission-ai/openspec": minor
+---
+
+### New Features
+
+- **Amp support**: select `amp` during init to install OpenSpec workflows as project skills under `.agents/skills/`.

docs-lab/reference/supported-tools.md

@@ -15,6 +15,7 @@ The id goes to `openspec init --tools <id>` to skip the picker ([CLI](cli.md)).
 | Tool | `--tools` id | Skills | Skill invocation | Commands | Command invocation |
 |---|---|---|---|---|---|
 | Amazon Q Developer | `amazon-q` | `.amazonq/skills/` | `/openspec-apply-change` | `.amazonq/prompts/` | `@opsx-apply` |
+| Amp | `amp` | `.agents/skills/` | `/openspec-apply-change` | none | none |
 | Antigravity | `antigravity` | `.agents/skills/` | `/openspec-apply-change` | `.agents/workflows/` | `/opsx-apply` |
 | Auggie (Augment CLI) | `auggie` | `.augment/skills/` | `/openspec-apply-change` | `.augment/commands/` | `/opsx-apply` |
 | Bob Shell | `bob` | `.bob/skills/` | `/openspec-apply-change` | `.bob/commands/` | `/opsx-apply` |
@@ -62,15 +63,22 @@ The id goes to `openspec init --tools <id>` to skip the picker ([CLI](cli.md)).
 
 A tool not listed here behaves exactly as its row reads.
 
+### Amp
+
+- **Project skills**: Amp reads OpenSpec skills from `.agents/skills/`.
+- **No command files**: Amp runs skills directly, so init skips command generation.
+- **Shared folder**: Amp shares `.agents/skills/` with Antigravity, Codex, Zed Agent,
+  and the `agents` target. OpenSpec writes the skill tree once.
+
 ### Antigravity
 
 - **Current folder**: Antigravity v1.20.5 and later read workspace skills and
   workflows from `.agents/`.
 - **Legacy folder**: after OpenSpec writes replacements, it removes equivalent
   generated files from `.agent/`. Custom files and changed generated files stay in
   `.agent/` for you to review.
-- **Shared skills**: Antigravity shares `.agents/skills/` with Codex, Zed Agent, and
-  the `agents` target. OpenSpec writes that skill tree once while still writing
+- **Shared skills**: Antigravity shares `.agents/skills/` with Amp, Codex, Zed Agent,
+  and the `agents` target. OpenSpec writes that skill tree once while still writing
   Antigravity commands to `.agents/workflows/`.
 
 ### Cline
@@ -88,10 +96,10 @@ Skills stay in `.cline/skills/`.
   describes both interfaces.
 - **No command files**: Codex runs skills directly, so init skips commands even when
   delivery includes them and prints `Commands skipped for: codex (uses skills)`.
-- **Shared folder**: Codex skills land in `.agents/skills/`, the same tree Antigravity,
-  Zed Agent, and the `agents` target use. Selecting more than one keeps a single
-  compatible tree, and its handoffs spell both `$openspec-*` and `/openspec-*` when
-  Codex owns it.
+- **Shared folder**: Codex skills land in `.agents/skills/`, the same tree Amp,
+  Antigravity, Zed Agent, and the `agents` target use. Selecting more than one keeps a
+  single compatible tree, and its handoffs spell both `$openspec-*` and `/openspec-*`
+  when Codex owns it.
 - **Legacy path**: skills installed under `.codex/skills/` by older versions are
   migrated on the next `openspec update`.
 
@@ -134,7 +142,7 @@ init prints this reminder after install.
   assistant is not listed. The init picker's search box finds it by `universal`,
   `other`, `generic`, `custom`, `proprietary`, `unlisted`, `unsupported`,
   `vendor-neutral`, or `agents.md`.
-- **Alongside other targets**: Antigravity, Codex, Zed Agent, and this target share
+- **Alongside other targets**: Amp, Antigravity, Codex, Zed Agent, and this target share
   one physical skill tree. OpenSpec records one writer in `.openspec-target` and
   writes the tree once per run. Each tool's separate command files are still
   generated.

openspec/changes/add-amp-support/.openspec.yaml

@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2025-12-29

openspec/changes/add-amp-support/proposal.md

@@ -0,0 +1,31 @@
+## Why
+
+Amp reads project skills from `.agents/skills/`, but OpenSpec does not list Amp in its tool picker or accept `amp` through `--tools`. Amp users can select the universal `.agents` target, but only if they already know how Amp discovers skills.
+
+## What Changes
+
+- Add Amp as a supported skills-only tool with `amp` as its tool id.
+- Generate Amp's OpenSpec skills through the existing shared `.agents/skills/` pipeline.
+- Detect Amp projects from `.amp/` and recognize Amp-owned OpenSpec skill trees during update.
+- Document Amp's paths and invocation syntax in the docs-lab supported-tools reference.
+
+## Capabilities
+
+### New Capabilities
+
+_None._
+
+### Modified Capabilities
+
+- `ai-tool-paths`: define Amp's shared Agent Skills path and skills-only behavior.
+
+## Impact
+
+- `src/core/config.ts`: add the Amp tool metadata.
+- `test/core/init.test.ts`, `test/core/update.test.ts`, and `test/core/available-tools.test.ts`: cover generation, refresh, and detection.
+- `docs-lab/reference/supported-tools.md`: add Amp to the support matrix and shared-folder notes.
+
+## Non-Goals
+
+- Adding an Amp command adapter. Amp's supported project extension surface is Agent Skills.
+- Adding a second Amp-specific skill generator or template set.

openspec/changes/add-amp-support/specs/ai-tool-paths/spec.md

@@ -0,0 +1,28 @@
+## ADDED Requirements
+
+### Requirement: Amp skills integration
+
+OpenSpec SHALL expose Amp as a supported skills-only tool that uses Amp's project Agent Skills directory.
+
+#### Scenario: Selecting Amp
+
+- **WHEN** the user selects Amp in `openspec init` or passes `--tools amp`
+- **THEN** OpenSpec SHALL generate the active profile's skills under `.agents/skills/`
+- **AND** the generated skills SHALL use `/openspec-<skill>` references
+- **AND** OpenSpec SHALL NOT generate command files for Amp
+
+#### Scenario: Detecting an Amp project
+
+- **WHEN** a project contains an `.amp/` directory
+- **THEN** OpenSpec SHALL detect Amp as an available tool
+
+#### Scenario: Updating an Amp-owned skill tree
+
+- **GIVEN** `.agents/skills/.openspec-target` names `amp`
+- **WHEN** `openspec update` runs
+- **THEN** OpenSpec SHALL refresh the Amp skill tree through the shared skill generator
+
+#### Scenario: Sharing the Agent Skills directory
+
+- **WHEN** Amp is selected with another tool that writes `.agents/skills/`
+- **THEN** OpenSpec SHALL write one compatible skill tree rather than letting the tools overwrite each other

openspec/changes/add-amp-support/tasks.md

@@ -0,0 +1,20 @@
+## 1. Tool support
+
+- [x] 1.1 Add Amp to `AI_TOOLS` as a skills-only `.agents` target.
+- [x] 1.2 Detect Amp projects from `.amp/` and preserve shared-root ownership.
+
+## 2. Documentation
+
+- [x] 2.1 Add Amp to the docs-lab supported-tools matrix.
+- [x] 2.2 Document Amp's skills-only and shared-folder behavior.
+
+## 3. Tests
+
+- [x] 3.1 Cover Amp detection from `.amp/` and `.openspec-target`.
+- [x] 3.2 Cover init generation, Agent Skills frontmatter, invocation syntax, and command skipping.
+- [x] 3.3 Cover update of an Amp-owned shared skill tree.
+
+## 4. Verification
+
+- [x] 4.1 Validate `add-amp-support` in strict mode.
+- [x] 4.2 Run targeted tests, lint, build, and the full test suite.

src/core/config.ts

@@ -40,6 +40,7 @@ export interface AIToolOption {
 
 export const AI_TOOLS: AIToolOption[] = [
   { name: 'Amazon Q Developer', value: 'amazon-q', available: true, successLabel: 'Amazon Q Developer', skillsDir: '.amazonq', requiresIdeRestart: true },
+  { name: 'Amp', value: 'amp', available: true, successLabel: 'Amp', skillsDir: '.agents', detectionPaths: ['.amp', '.agents/skills'] },
   // Antigravity moved workspace skills and workflows from `.agent` to the
   // shared `.agents` root in v1.20.5. Detection keys off `.agent` and
   // `.agents/workflows` rather than the bare `.agents` root: that root is

test/core/available-tools.test.ts

@@ -141,6 +141,12 @@ describe('available-tools', () => {
       expect(tools[0].skillsDir).toBe('.agents');
     });
 
+    it('should detect Amp from its project configuration directory', async () => {
+      await fs.mkdir(path.join(testDir, '.amp'), { recursive: true });
+
+      expect(getAvailableTools(testDir).map((tool) => tool.value)).toEqual(['amp']);
+    });
+
     it('should detect Antigravity from .agents/workflows', async () => {
       await fs.mkdir(path.join(testDir, '.agents', 'workflows'), { recursive: true });
 
@@ -203,6 +209,13 @@ describe('available-tools', () => {
       expect(getAvailableTools(testDir).map((tool) => tool.value)).toEqual(['zed']);
     });
 
+    it('should use the shared-root marker to detect a configured Amp target', async () => {
+      await fs.mkdir(path.join(testDir, '.agents', 'skills'), { recursive: true });
+      await fs.writeFile(path.join(testDir, '.agents', 'skills', '.openspec-target'), 'amp\n');
+
+      expect(getAvailableTools(testDir).map((tool) => tool.value)).toEqual(['amp']);
+    });
+
     it('should preserve a global tool while reconciling a shared project root', async () => {
       const sharedSkills = path.join(testDir, '.agents', 'skills');
       const globalSkill = path.join(

test/core/init.test.ts

@@ -711,6 +711,34 @@ describe('InitCommand', () => {
       ).toBe(true);
     });
 
+    it('should support Amp through its shared Agent Skills directory', async () => {
+      saveGlobalConfig({
+        featureFlags: {},
+        profile: 'core',
+        delivery: 'both',
+      });
+
+      await new InitCommand({ tools: 'amp', force: true }).execute(testDir);
+
+      const skillsDir = path.join(testDir, '.agents', 'skills');
+      const skillFile = path.join(skillsDir, 'openspec-explore', 'SKILL.md');
+      expect(await fileExists(skillFile)).toBe(true);
+      expect(await fs.readFile(path.join(skillsDir, '.openspec-target'), 'utf-8')).toBe('amp\n');
+
+      const skillContent = await fs.readFile(skillFile, 'utf-8');
+      expect(skillContent).toContain('name: openspec-explore');
+      expect(skillContent).toContain('/openspec-');
+      expect(skillContent).not.toContain('/opsx:');
+      expect(await directoryExists(path.join(testDir, '.agents', 'commands'))).toBe(false);
+
+      const logCalls = vi.mocked(console.log).mock.calls.flat().map(String);
+      expect(
+        logCalls.some(
+          (entry) => entry.includes('Commands skipped for: amp') && entry.includes('(no adapter)')
+        )
+      ).toBe(true);
+    });
+
     it('should install MiniMax Code skills only in the user-home target', async () => {
       saveGlobalConfig({
         featureFlags: {},

test/core/update.test.ts

@@ -627,6 +627,21 @@ metadata:
       ).toBe(true);
     });
 
+    it('should refresh an Amp-owned shared skill tree', async () => {
+      await new InitCommand({ tools: 'amp', force: true }).execute(testDir);
+      const skillsDir = path.join(testDir, '.agents', 'skills');
+      const skillFile = path.join(skillsDir, 'openspec-propose', 'SKILL.md');
+      await fs.writeFile(skillFile, 'stale Amp skill');
+
+      await new UpdateCommand({ force: true }).execute(testDir);
+
+      expect(await fs.readFile(path.join(skillsDir, '.openspec-target'), 'utf-8')).toBe('amp\n');
+      const updated = await fs.readFile(skillFile, 'utf-8');
+      expect(updated).toContain('name: openspec-propose');
+      expect(updated).toContain('/openspec-apply-change');
+      expect(updated).not.toContain('stale Amp skill');
+    });
+
     it('should refresh Antigravity workflows without rewriting Codex-owned shared skills', async () => {
       await new InitCommand({ tools: 'antigravity,codex', force: true }).execute(testDir);