Second Brain PRD Generator

Generate a personalized Product Requirements Document for building an AI Second Brain, based on the user's completed requirements template.

A blank template is bundled with this skill at ${CLAUDE_SKILL_DIR}/my-second-brain-requirements.md. Copy it to your workspace and fill it out before running this skill.

Parameters

• $0 (required) — Path to the filled-out requirements file (e.g., ./my-second-brain-requirements.md)
• $1 (optional) — Output path for the PRD. Defaults to .agent/plans/second-brain-prd.md

Workflow

1. Read the requirements — Read the filled-out requirements file at $0. If no argument was provided, ask the user for the path. If they haven't filled one out yet, tell them a blank template is available at ${CLAUDE_SKILL_DIR}/my-second-brain-requirements.md — they should copy it to their workspace and fill it out first.

2. Load the architecture reference — Read ${CLAUDE_SKILL_DIR}/references/architecture-reference.md for the blueprint.

3. Research ALL tools and APIs — Do not assume familiarity with any platform or library. Even common APIs like Gmail or Slack have nuances, rate limits, and SDK-specific patterns that matter for implementation. For every tool in the user's stack, do web research to ensure the PRD contains accurate, specific guidance.

   Always research these core dependencies:

   • Claude Agent SDK — How to create conversations, system_prompt presets, setting_sources, allowed_tools, streaming responses, credential handling
   • FastEmbed — ONNX model loading, batch embedding API, model cache configuration, supported models
   • Hook system — Claude Code hook types (PreToolUse, PostToolUse, etc.), callback signatures, settings.json configuration

   For every platform the user selected (Gmail, Slack, Linear, HubSpot, etc.):

   • Authentication method (OAuth2 flow, API tokens, bot tokens, etc.)
   • Key SDK/library to use (e.g., google-api-python-client, slack_sdk, etc.)
   • The specific API endpoints needed for the user's top tasks
   • Platform-specific setup requirements (e.g., Slack Socket Mode needs an App Token + Bot Token, Gmail needs OAuth consent screen published to Production for custom domains)
   • Rate limits, pagination patterns, and common gotchas

   The goal: Every phase in the PRD should contain enough technical specificity that a coding agent can implement it without guessing. Don't bloat the PRD with raw research - distill it into actionable implementation notes per phase.

4. Generate the PRD — Create a phased build plan at the output path ($1, or .agent/plans/second-brain-prd.md if not specified) with these sections:

PRD Structure

The output PRD should have:

Header:

• Project name (personalized: "[User's Name]'s Second Brain")
• Date generated
• Summary: 1-2 sentences based on their top tasks

Phase 1: Foundation (Memory Layer)

• Set up Obsidian vault (or their preferred notes app integration)
• Create SOUL.md, USER.md, MEMORY.md, daily/ structure
• Customize each file based on their "About You" and "Memory Categories" answers
• Key files to create, estimated complexity: Low

Phase 2: Hooks (Context Persistence)

• SessionStart hook (inject memory into every conversation)
• PreCompact hook (save context before auto-compaction)
• SessionEnd hook (save context on exit)
• Key files, estimated complexity: Medium

Phase 3: Memory Search (Hybrid RAG)

• Set up chunking + embedding pipeline
• SQLite + sqlite-vec + FTS5 (local) or Postgres + pgvector (VPS)
• Hybrid search: 0.7 vector + 0.3 keyword
• Key files, estimated complexity: Medium

Phase 4: Integrations (Their Top 3 First)

• Use their "Integration Priority" rankings
• For each: auth setup, API module, registry entry, query.py subcommand
• Reference the integration_template.py pattern
• Key files per integration, estimated complexity: Medium per integration

Phase 5: Skills (Starter Pack)

• Vault structure skill (teach agent their file organization)
• At least one custom skill based on their "Top Tasks"
• Skill anatomy: SKILL.md + scripts/ + references/
• Key files, estimated complexity: Low-Medium

Phase 6: Proactive Systems (Heartbeat + Reflection)

• Heartbeat: gather data from integrations → Claude reasons → notify
• Set schedule based on their proactivity level
• Daily reflection: promote important daily log items to MEMORY.md
• Map their proactivity level choice to specific heartbeat behaviors
• Draft management: Heartbeat scans platforms for messages needing a reply, generates drafts in the user's voice (stored in drafts/active/), tracks lifecycle (active → sent → expired after 24h), uses RAG on drafts/sent/ for voice-matching
• Habits tracking: HABITS.md with customizable pillars, auto-detection rules for objective achievements, daily reset by heartbeat, late-day nudges for unchecked pillars
• Key files, estimated complexity: High

Phase 7: Chat Interface (Optional)

• Only include if they checked Chat/Messaging in platforms
• Slack/Discord bot with persistent conversations
• Platform adapter pattern for extensibility
• Key files, estimated complexity: High

Phase 8: Security Hardening

• Sanitize all external data (3-layer defense)
• Command guardrails based on their Security Boundaries answers
• API key isolation (Python CLI wrapper pattern)
• Key files, estimated complexity: Medium

Phase 9: Deployment

• Based on their Infrastructure answers
• Local: OS scheduler setup (Windows Task Scheduler / cron / launchd)
• If VPS: server setup, vault sync, SSH tunnel
• Cost estimate based on their choices

Each phase includes:

• What to build (1-2 sentences)
• Key files to create (with paths)
• Dependencies (which phases must come first)
• Estimated complexity (Low / Medium / High)
• Personalization notes (how their specific answers shape this phase)

Footer:

• Recommended build order (phases are mostly sequential but some can parallel)
• "This PRD was generated from your requirements. Revisit and update as your system evolves."

5. Confirm output — Tell the user where the PRD was saved (the output path) and suggest they start with Phase 1.

Personalization Rules

• Use THEIR platform names everywhere (not generic "email" — use "Gmail" if that's what they chose)
• Map their proactivity level to concrete behaviors:
  • Observer → heartbeat notifications only, no drafting, no habit tracking
  • Advisor → heartbeat + draft emails/messages for review, habit tracking with suggestions but no auto-check
  • Assistant → heartbeat + drafts + auto-organize files + auto-log, habit auto-detection for objective pillars
  • Partner → all of the above + send low-risk messages + auto-complete routine tasks + full habit auto-detection
• Map their security boundaries directly into Phase 8 guardrail rules
• Use their memory categories to structure the vault folders in Phase 1
• Their integration priority determines Phase 4 order