git:20260610.f7e8221 to git:20260712.fbb5616
6 added, 6 removed. Audit A to A.
---
name: hephaestus-agent
description: Developer reference for the Hephaestus autonomous deep worker agent — model variants, key behaviors, and delegation patterns.
---
# src/agents/hephaestus/ -- Autonomous Deep Worker
**Generated:** 2026-05-15
## OVERVIEW
- 6 files. Hephaestus agent -- autonomous deep worker powered by GPT-5.5. Goal-oriented: give it objectives, not step-by-step instructions. "The Legitimate Craftsman."
+ 6 files. Hephaestus agent -- autonomous deep worker with GPT-5.4, GPT-5.5, GPT-5.6, and base-prompt variants. Goal-oriented: give it objectives, not step-by-step instructions. "The Legitimate Craftsman."
## FILES
| File | Purpose |
|------|---------|
| `agent.ts` | `createHephaestusAgent()` factory, model-variant routing |
| `gpt.ts` | Base GPT prompt: discipline rules, delegation, verification |
- | `gpt-5-5.ts` | GPT-5.5-native prompt tuned for current Hephaestus routing |
+ | `gpt-5-6.ts` | GPT-5.6-native outcome-first prompt |
+ | `gpt-5-5.ts` | GPT-5.5-native prompt with task discipline sections |
| `gpt-5-4.ts` | GPT-5.4-native prompt with XML-tagged blocks, entropy-reduced |
- | `gpt-5-5.ts` | GPT-5.5 variant with task discipline sections |
| `index.ts` | Barrel exports |
## KEY BEHAVIORS
- Mode: `primary` (respects UI model selection)
- Requires OpenAI-compatible provider (no fallback chain)
- NEVER trusts subagent self-reports -- always verifies
- NEVER uses `background_cancel(all=true)`
- Delegates exploration to background agents, never sequential
- Uses `run_in_background=true` for explore/librarian
## MODEL VARIANTS
| Model | Prompt Source | Optimizations |
|-------|-------------|---------------|
- | gpt-5.5 | `gpt-5-5.ts` | GPT-5.5-tuned prompt architecture |
+ | gpt-5.6 | `gpt-5-6.ts` | Outcome-first, manual-QA-focused prompt |
+ | gpt-5.5 | `gpt-5-5.ts` | Task discipline prompt |
| gpt-5.4 | `gpt-5-4.ts` | XML-tagged blocks, 8 sections |
- | gpt-5.5 | `gpt-5-5.ts` | Task discipline, 549 LOC prompt |
- | Other GPT | `gpt.ts` | Base prompt, 507 LOC |
+ | Other supported GPT | `gpt.ts` | Base prompt |