Document Gemini CLI slash updates (#301)

Author: TabishB

.repo-updates-log

@@ -231,6 +231,13 @@ The init command SHALL generate slash command files for supported editors using
 - **AND** wrap the shared template body with OpenSpec markers so `openspec update` can refresh the content
 - **AND** each template includes instructions for the relevant OpenSpec workflow stage
 
+#### Scenario: Generating slash commands for Gemini CLI
+- **WHEN** the user selects Gemini CLI during initialization
+- **THEN** create `.gemini/commands/openspec/proposal.toml`, `.gemini/commands/openspec/apply.toml`, and `.gemini/commands/openspec/archive.toml`
+- **AND** populate each file as TOML that sets a stage-specific `description = "<summary>"` and a multi-line `prompt = """` block with the shared OpenSpec template
+- **AND** wrap the OpenSpec managed markers (`<!-- OPENSPEC:START -->` / `<!-- OPENSPEC:END -->`) inside the `prompt` value so `openspec update` can safely refresh the body between markers without touching the TOML framing
+- **AND** ensure the slash-command copy matches the existing proposal/apply/archive templates used by other tools
+
 ### Requirement: Non-Interactive Mode
 The command SHALL support non-interactive operation through command-line options for automation and CI/CD use cases.
 

openspec/specs/cli-init/spec.md

@@ -117,6 +117,12 @@ The update command SHALL refresh existing slash command files for configured too
 - **AND** update only the OpenSpec-managed block between markers
 - **AND** ensure templates include instructions for the relevant workflow stage
 
+#### Scenario: Updating slash commands for Gemini CLI
+- **WHEN** `.gemini/commands/openspec/` contains `proposal.toml`, `apply.toml`, and `archive.toml`
+- **THEN** refresh the body of each file using the shared proposal/apply/archive templates
+- **AND** replace only the content between `<!-- OPENSPEC:START -->` and `<!-- OPENSPEC:END -->` markers inside the `prompt = """` block so the TOML framing (`description`, `prompt`) stays intact
+- **AND** skip creating any missing `.toml` files during update; only pre-existing Gemini commands are refreshed
+
 #### Scenario: Missing slash command file
 - **WHEN** a tool lacks a slash command file
 - **THEN** do not create a new file during update

openspec/specs/cli-update/spec.md

@@ -588,6 +588,54 @@ Old body
     await expect(FileSystemUtils.fileExists(ghArchive)).resolves.toBe(false);
   });
 
+  it('should refresh existing Gemini CLI TOML files without creating new ones', async () => {
+    const geminiProposal = path.join(
+      testDir,
+      '.gemini/commands/openspec/proposal.toml'
+    );
+    await fs.mkdir(path.dirname(geminiProposal), { recursive: true });
+    const initialContent = `description = "Scaffold a new OpenSpec change and validate strictly."
+
+prompt = """
+<!-- OPENSPEC:START -->
+Old Gemini body
+<!-- OPENSPEC:END -->
+"""
+`;
+    await fs.writeFile(geminiProposal, initialContent);
+
+    const consoleSpy = vi.spyOn(console, 'log');
+
+    await updateCommand.execute(testDir);
+
+    const updated = await fs.readFile(geminiProposal, 'utf-8');
+    expect(updated).toContain('description = "Scaffold a new OpenSpec change and validate strictly."');
+    expect(updated).toContain('prompt = """');
+    expect(updated).toContain('<!-- OPENSPEC:START -->');
+    expect(updated).toContain('**Guardrails**');
+    expect(updated).toContain('<!-- OPENSPEC:END -->');
+    expect(updated).not.toContain('Old Gemini body');
+
+    const geminiApply = path.join(
+      testDir,
+      '.gemini/commands/openspec/apply.toml'
+    );
+    const geminiArchive = path.join(
+      testDir,
+      '.gemini/commands/openspec/archive.toml'
+    );
+
+    await expect(FileSystemUtils.fileExists(geminiApply)).resolves.toBe(false);
+    await expect(FileSystemUtils.fileExists(geminiArchive)).resolves.toBe(false);
+
+    const [logMessage] = consoleSpy.mock.calls[0];
+    expect(logMessage).toContain(
+      'Updated slash commands: .gemini/commands/openspec/proposal.toml'
+    );
+
+    consoleSpy.mockRestore();
+  });
+
   it('should refresh existing Factory slash commands', async () => {
     const factoryPath = path.join(
       testDir,