S3YED External AI Coding Agents
Delegate coding work to third-party AI coding agents from within Hermes. These tools (Claude Code, Codex, OpenCode) are autonomous CLI agents that can read files, write code, run shell commands, and manage git workflows — each with its own strengths.
When to Delegate vs Do It Yourself
| Situation | Approach |
|---|---|
| Bug fix in a known file | Do it yourself with patch/write_file — faster, no overhead |
| Complex multi-file refactor | Delegate — the external agent has persistent context across files |
| Task needs a fresh perspective | Delegate — the external agent will spot things you might miss |
| CI/CD automation | Delegate — use print mode for clean automation |
| PR review of someone else's code | Delegate — the external agent can see the full diff in context |
| Research/reconnaissance | Delegate — agent can browse and explore independently |
| Simple one-line change | Do it yourself |
Common Orchestration Patterns
All three coding agents use the same core patterns:
Print Mode (Non-Interactive — Preferred)
Cleanest integration. No PTY, no dialog handling, structured output:
terminal(command="<agent> -p 'Add error handling to all API calls in src/'", workdir="/path/to/project", timeout=120)
PTY Background Mode (Interactive)
For iterative work needing multi-turn conversation. Use background=true, pty=true and process tool to monitor:
terminal(command="<agent>", workdir="~/project", background=true, pty=true)
process(action="submit", session_id="<id>", data="Implement OAuth refresh flow")
process(action="poll", session_id="<id>")
process(action="log", session_id="<id>")
process(action="kill", session_id="<id>")
Get the Diff Back
After delegation completes, always inspect what changed:
git diff
git diff --stat
Agent Decision Guide
| Need | Best Agent | Why |
|---|---|---|
| Best overall coding ability | Claude Code | Anthropic's most capable model, v2.2+, rich feature set |
| Cheapest / open-source preference | OpenCode | Provider-agnostic (OpenRouter, Anthropic, OpenAI, local models) |
| OpenAI ecosystem | Codex | OpenAI's autonomous agent, OAuth integration |
| PR review with inline comments | Claude Code | Built-in --from-pr flag, formal review workflow |
| Batch multi-issue fixing | Codex or OpenCode | Lightweight, parallel worktree pattern |
| Long-running autonomous session | Any | Use background=true + process tool for monitoring |
Common Pitfalls
- PTY is required for interactive sessions — all three agents are TUI apps; skip
pty=trueand they hang - Git repo required — Codex and OpenCode refuse to run outside a git directory. Use
mktemp -d && git initfor scratch work - Always inspect the diff after delegation — external agents can make surprising decisions. Use
git diff --statto verify scope - Keep tasks focused — narrow prompts produce better results than vague requests
- Set timeouts — external agents can loop indefinitely. Use
--max-turns(Claude Code) ortimeoutin terminal calls - Cleanup background sessions — kill tmux sessions and worktree directories when done
- Parallel worktrees need isolation — don't share a single working directory across parallel agents
Agent-Specific References
Detailed reference docs for each agent:
- references/claude-code.md — Full Claude Code orchestration guide (flags, auth, hooks, MCP, slash commands, 745 lines)
- references/codex.md — Codex CLI usage (flags, background mode, worktrees)
- references/opencode.md — OpenCode CLI usage (binary resolution, parallel patterns, TUI keybindings)
Getting Started
Which Agent is Installed?
which claude codex opencode 2>/dev/null || echo "check npm list -g"
Quick One-Shot (any agent)
# Claude Code
terminal(command="claude -p 'Add input validation to all endpoint handlers' --max-turns 10", workdir="~/project", timeout=120)
# Codex
terminal(command="codex exec 'Add input validation to all endpoint handlers'", workdir="~/project", pty=true)
# OpenCode
terminal(command="opencode run 'Add input validation to all endpoint handlers'", workdir="~/project")