new-agent

name	new-agent
description	You MUST use the new-agent skill when asked to add a implement a agent in lanes.

New Agent Implementation

You are implementing a new code agent backend for the Lanes VS Code extension.

IRON LAW: Agent Abstraction

When implementing new agents DO NOT add agent specific logic to any files outside of the src/codeAgents/<ClassName>.ts files.

Step 0: Gather information

Ask the user for:

1. Agent internal name - lowercase identifier, e.g. aider
2. Display name - user-facing label, e.g. Aider
3. CLI command - shell command that launches the agent, e.g. aider
4. Data directory - where the agent stores config, e.g. .aider
5. Logo SVG - inline SVG for the dropdown (ask the user to provide one, or search for the official logo)

Also determine these behavioral traits:

• Hooks: Does the CLI emit lifecycle events (SessionStart, Stop, etc.)? If no, it's "hookless" and needs captureSessionId() — use CodexAgent.ts as reference.
• Prompt passing: Positional argument (cli 'prompt') or stdin?
• MCP support: If yes, how is config delivered — CLI flag, settings file, or -c overrides?
• Permission modes: What flags does the CLI accept? (e.g. --yes, --yolo, --bypass)
• Session ID format: UUID, numeric index, or something else?
• Resume support: Does the CLI support --resume? What format?

Step 1: Study the base class and a reference agent

Read these files to understand the current abstract contract:

• src/codeAgents/CodeAgent.ts — the abstract base class defines all required and optional methods, interfaces, and types. This is the source of truth for what must be implemented.
• Pick the closest existing agent as reference:
  • Hook-based with MCP via CLI flag: ClaudeCodeAgent.ts
  • Hookless with MCP via CLI overrides: CodexAgent.ts
  • Hook-based with MCP via settings file: GeminiAgent.ts
  • Hook-based without MCP, stdin prompts: CortexCodeAgent.ts

Step 2: Create the agent class

Create src/codeAgents/<ClassName>.ts using the reference agent from Step 1 as a template. Implement every abstract method from CodeAgent.ts and override optional base class methods as needed based on the agent's capabilities.

Step 3: Register the agent

1. Factory (src/codeAgents/factory.ts): add import and entry to agentConstructors map
2. Barrel (src/codeAgents/index.ts): add export for the new class
3. Settings schema (package.json): add to lanes.defaultAgent enum and enumDescriptions

No UI changes are needed — the dropdown derives from getAvailableAgents() + getAgent() automatically.

Step 4: Write tests

Create src/test/codeAgents/<name>-agent.test.ts following the pattern in an existing test file (e.g. gemini-agent.test.ts). Cover: config values, command building, session/status parsing, permission modes, terminal config, hooks, and MCP.

Constraints

• sessionFileExtension MUST be .claude-session and statusFileExtension MUST be .claude-status — all agents share these filenames and existing sessions depend on them.
• Session IDs MUST be validated against a strict regex before use in shell commands (command injection prevention).
• Prompt text MUST be escaped when embedded in shell commands.

Verification

1. npm run compile — no TypeScript errors
2. npm run lint — no lint errors
3. npm test — all tests pass
4. Manual: create a session with the new agent in Extension Development Host (F5)