Module 2.1: Write a PRD

Reference Guide

Time to Complete: 30-45 minutes
Prerequisites: Module 1 complete (especially @-mentions, agents, and sub-agents)

Start this lesson interactively: Type /start 2 1 in the Codex app to write a real PRD step-by-step.

Overview

Module 2 applies everything from the fundamentals to realistic, advanced PM scenarios. This first lesson is about writing Product Requirements Documents — but the real lesson is how to work with AI on important documents.

Key takeaway: Codex is a thinking partner, not a ghostwriter. The pattern is always: you think, Codex augments, you decide. Because Codex can hold full context — company docs, research, templates, user data — all at once, it helps you think through problems with everything relevant at its fingertips.

Step 1 — Choose a Template

Templates give your thinking structure. The lesson offers two, and you can bring your own:

Template	Best for
Carl’s PRD Template	Complex features. Detailed sections for Problem Alignment (problem & opportunity, high-level approach, narrative, goals, non-goals), Solution Alignment (key features, flows, logic), and Development & Launch Planning.
Lenny’s PRD Template	Smaller features or early-stage thinking. Minimal — seven questions: Description, Problem, Why, Success, Audience, What, How, When.

Step 2 — Bring in Context with @-Mentions

Kick off the PRD by referencing the files Codex needs, all at once:

Please help me fill out @Lennys-PRD-Template.md for an AI voice chat interface for managing a to-do list. Use @taskflow-company-context.md and guide me through the process using @socratic-questioning.md. My ideas are [your ideas]

This pulls in three things: the company context (so Codex knows the product and customers), a Socratic questioning framework (so it can sharpen your thinking), and your chosen template (the structure).

Step 3 — Sharpen Your Thinking with Socratic Questions

Before writing anything, Codex asks you 3-5 targeted questions drawn from the framework. This is where the partnership shines — it helps you refine the idea before a single word of the PRD is written. You can answer thoughtfully, or skip and let Codex suggest reasonable answers from the company context. You can also pull in user research at this stage to ground the PRD in real pain points.

Step 4 — Generate Multiple Strategic Approaches

Instead of one draft you hope is right, have Codex generate three — each using your template but taking a different strategic angle. For the AI voice chat example:

Version 1 — Chat-first: AI conversation is primary, the list is secondary
Version 2 — List-first: a traditional to-do list enhanced with AI voice
Version 3 — Balanced: equal weight to both

This is a perfect use of parallel agents. You review all three, then pick the one that resonates — or mix and match.

Spin up 3 agents to generate 3 PRD drafts

Step 5 — Get Multi-Perspective Feedback Before Anyone Sees It

Use the specialist sub-agents from Module 1.5 to review your chosen draft from three angles:

Engineer — technical feasibility and implementation complexity
Executive — business value and strategic fit
User Researcher — user needs and usability

Get reviews from all three agents and put them in a new doc

You get an engineer’s, an executive’s, and a researcher’s perspective in minutes — letting you strengthen the PRD before sharing it with your actual team. Then work through the feedback with Codex and save a final version.

The Workflow in Summary

Choose a template
Bring in context, research, and a questioning framework via @-mentions
Let Socratic questions sharpen your thinking
Generate three strategic approaches in parallel
Get multi-perspective sub-agent feedback
Address feedback and finalize

You drove every decision — which template, which approach, which feedback to address. Codex helped you think better and move faster.

Other Ways Codex Helps with PRDs

Competitive research — web search competitors and synthesize their approaches
User interview synthesis — read dozens of transcripts and pull out themes
Product analytics analysis — analyze usage data to inform prioritization
Section-by-section drafting — you write one section, Codex helps with the next, iterating together

What’s Next

Next up is Module 2.2: Analyze Data — using data to discover problems, estimate feature impact, and analyze A/B test results.

Start it by typing /start 2 2 in the Codex app, or read the reference guide:

Go to Module 2.2: Analyze Data →

1.6: Project Memory 2.2: Analyze Data