---
title: "Zero-Hallucination Coder"
type: skill
id: "rezvani-skills/engineering-review/zero-hallucination-coder"
category: "Engineering"
publisher: "Alireza Rezvani"
license: "MIT"
source: "https://github.com/alirezarezvani/claude-skills/tree/c85b17e"
canonical: "https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/zero-hallucination-coder"
open_in_pho: "https://pho.chat/customize?item=rezvani-skills%2Fengineering-review%2Fzero-hallucination-coder&utm_source=labs&utm_medium=skill-page&utm_campaign=skills-library"
---

# Zero-Hallucination Coder

Use before high-stakes or multi-file coding (auth, databases, migrations), or when asked to plan carefully and avoid invented APIs. Runs discuss, map, decompose, execute and verify, checking every import and API exists. Not for trivial edits.

Source: Alireza Rezvani (MIT), copied at a pinned commit. Free to use. Part of the Phở Skills library (https://labs.pho.chat/en/skills).
Skill set: Engineering review (https://labs.pho.chat/en/skills/rezvani-skills/engineering-review.md).

## What it covers
- When to invoke (opt-in discipline)
- Credits & Inspiration
- Before Starting
- Modes
- The Five-Phase Loop
  - Phase 1: DISCUSS
  - Phase 2: MAP
  - Phase 3: DECOMPOSE
  - Phase 3.5: PONYTAIL CHECK (runs before every story)
  - Phase 4: EXECUTE
  - Phase 5: VERIFY
- Anti-Patterns (Rules 1-7 — always on, even when short-circuiting)
- Context Engineering Rules
- When to Short-Circuit
- Proactive Triggers
- Output Artifacts
- Cross-References

## Other skills in this set
- [PR Review Expert](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/pr-review-expert.md): Review a pull request or diff for bugs, security and quality, file by file. Use whenever the user asks to review a PR or look over their changes.
- [Adversarial Code Reviewer](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/adversarial-reviewer.md): Tough, critical review of a diff or PR before merge, through hostile reviewer personas that catch shared blind spots. Use whenever the user wants a change torn apart, a harsh second opinion, or a…
- [Database Schema Designer](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/database-schema-designer.md): Use when asked for an ERD, table relationships, normalization or a schema migration plan. Produces the ERD and normalized DDL with migration steps.
- [API Test Suite Builder](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/api-test-suite-builder.md): Use when asked to write API, integration or contract tests for REST endpoints. Builds the suite from the routes: happy paths, auth, validation errors and edge cases per endpoint.
- [Focused Fix — Deep-Dive Feature Repair](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/focused-fix.md): Use when a whole feature or module is broken and needs fixing end to end ('make X work', 'the Y module is broken'). Maps every file and dependency of the area before changing anything. Single quick…
- [Security Guidance Hook](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/security-guidance.md): Use when installing or tuning the PreToolUse security hook that warns before Claude writes command injection, XSS, SQL injection, unsafe deserialization, eval or GitHub Actions injection. Warns once…
- [Stripe Integration Expert](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/stripe-integration-expert.md): Use for any Stripe integration: subscriptions, trials, proration, checkout, usage billing, webhooks, customer portal or invoicing in Next.js, Express or Django. Writes idempotent webhook handlers…
- [LLM Cost Optimizer](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/llm-cost-optimizer.md): Use whenever an LLM feature is being built or its costs come up (model choice, prompt caching, token limits, per-feature spend). Sets routing, caching, max_tokens and cost logging before launch…
- [Prompt Governance](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/prompt-governance.md): Use when prompts run in production and need versioning, a registry, A/B tests, regression checks or an eval pipeline. Sets up the release process for prompts; single-prompt quality…
- [Embedded / IoT Mentor](https://labs.pho.chat/en/skills/rezvani-skills/engineering-review/embedded-iot-mentor.md): Use for any embedded or IoT hardware project (ESP32, STM32, Arduino, Pico, firmware, PCB, MQTT, Home Assistant, sensor dashboards), before buying parts. Picks the MCU, board and toolchain, decides…

## Use it
- In Phở: open https://pho.chat/customize?item=rezvani-skills%2Fengineering-review%2Fzero-hallucination-coder&utm_source=labs&utm_medium=skill-page&utm_campaign=skills-library and press Try, or add it so Phở loads it whenever a request matches. Phở works with your own API key (OpenAI, Anthropic, Google and others).
- Full instructions (original SKILL.md, unchanged): https://labs.pho.chat/skills/raw/rezvani-skills/engineering-review/skills/zero-hallucination-coder/SKILL.md
- Original files: https://github.com/alirezarezvani/claude-skills/tree/c85b17e (MIT).
- Full machine-readable index: https://labs.pho.chat/skills.json