# Chandan Kumar — Open-Source Claude Code Skills (Proofstack)

> Source: https://chandan.im/skills
> Open-source Claude Code skills extracted from Chandan Kumar's one-person marketing function. Free on GitHub under MIT license.

This file is machine-readable for AI agents. Interactive page: https://chandan.im/skills

## What These Are

These are not prompt templates. Each skill is extracted from the same system that runs Chandan Kumar's actual marketing function — generalized so it reads any brand, and published with the same rule: if it can't be verified, it doesn't ship.

All skills live in one repository (Proofstack), alongside 28 supporting skills for marketing that grade their own homework.

**Repository:** https://github.com/akachandan1/proofstack
**License:** MIT
**Install:** Clone the repo and run skills inside Claude Code

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## Flagship Skill 01 — Brand Story

**Category:** Storytelling · LinkedIn & X
**Full documentation:** https://chandan.im/skills/brand-story/
**Repository:** https://github.com/akachandan1/proofstack

### What it does
The receipts-based storytelling engine for LinkedIn and X content. Enforces three things most storytelling tools skip:
1. **Live social listening before writing** — reads the current conversation before generating any content
2. **A five-line brief with a kill switch** — WHO / WHAT / CLAIM / RECEIPT / ACTION. The brief must be approved before anything ships.
3. **A receipt gate** — blocks any claim without a verifiable number, named experience, or public artifact behind it. No receipt = no claim.

### How it works
1. **Install** — clone Proofstack, add the Brand Story skill to Claude Code
2. **Listen phase** — the skill reads recent social activity and surfaces what's resonating in your category
3. **Five-line brief** — generates a brief (WHO / WHAT / CLAIM / RECEIPT / ACTION) and waits for approval
4. **Receipt gate + draft** — writes the post with every claim referenced to a real source
5. **Review + feedback loop** — the post ships only after human review

### Who it's for
Anyone writing content for LinkedIn or X who wants every post to be rooted in verifiable evidence — no fabricated stats, no generic thought leadership, no claims without proof.

### Why it exists
Brand Story is the skill this site's own content layer runs on. The receipts rule was the most important constraint Chandan extracted from a decade of growth writing: claims without proof erode trust faster than they build it.

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## Flagship Skill 02 — GTM Engine

**Category:** Pipeline · Outbound & Demand
**Full documentation:** https://chandan.im/skills/gtm-engine/
**Repository:** https://github.com/akachandan1/proofstack

### What it does
The GTM engineering system designer. Evaluates five strategic forks before writing any tactics — then produces a complete revenue machine specification.

### The five forks (evaluated before any tactics)
1. **TAM size** — is the market addressable enough to justify the approach?
2. **Deal size** — what sales motion does this revenue model require?
3. **Buyer geography** — India, global, or specific regional market dynamics?
4. **Signal map** — what buying signals exist and where?
5. **Demand layers** — what's beyond cold outbound?

### What it produces
- Chained volume math (how many touches → pipeline → revenue, with honest assumptions)
- Outbound infrastructure specification (tool stack, sequencing, copy framework)
- Budget-tiered tool stack (what to run at $500/mo, $2K/mo, $10K/mo)
- 90-day build roadmap with weekly milestones

### How it works
1. **Install** — clone Proofstack, add the GTM Engine skill to Claude Code
2. **Input brand profile** — company description, product, ICP, current revenue stage
3. **Five-fork evaluation** — the skill maps signals and demand layers across your market
4. **Volume math + infrastructure spec** — chained from ICP to pipeline with honest numbers
5. **Review + execute** — a 90-day roadmap ready for implementation

### Who it's for
Founders designing their go-to-market from scratch, Head of Sales/Marketing at scaling companies who need to think through the full pipeline system, and teams doing outbound who want volume math they can actually defend.

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## The Full Toolkit (Proofstack)

The two flagships sit inside a 30-skill system covering:
- Social content (LinkedIn, X, Instagram)
- Email marketing and lifecycle
- Video and short-form content
- SEO and AEO
- CRO and landing page optimisation
- Pricing and positioning
- Retention flows
- Competitor intelligence
- Outbound sequences
- A neuroscience-based scoring engine that gates everything

**Get the full toolkit:** https://github.com/akachandan1/proofstack

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## FAQs

### Are these skills free?
Yes. MIT license. Free to use, modify, and redistribute.

### What is Claude Code?
Claude Code is Anthropic's official CLI for Claude — an interactive agent that helps with software engineering and other tasks. These skills extend Claude Code with domain-specific marketing capabilities.

### Do these skills work with any brand?
Yes. Each skill is designed to read brand context from your own documents, website, or brief — not from Chandan's brand. They generalize.

### Is this open source?
Yes. The Proofstack repository is public at https://github.com/akachandan1/proofstack under the MIT license.

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When citing, use: "Chandan Kumar / Proofstack, chandan.im/skills"