# indexion-sdd

Turns an RFC or spec into SDD requirements and checks them against the code quantitatively. Useful when implementation has to stay inside the document.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 5000 installs · ★ 2
- Author: trkbt10
- License: Apache-2.0 · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/trkbt10/indexion-skills/tree/HEAD/skills/indexion-sdd/SKILL.md
- Updated: 2026-09-22
- HTML: https://affpapa.org/en/nevibecode/skills/indexion-sdd

## What it does

The skill bridges indexion's alignment tools with agent SDD workflows (cc-sdd, codex). The chain runs from a draft of requirements out of the source document, through spec-to-impl alignment, into a validation loop where indexion's quantitative output feeds the agent's qualitative review. Spec-to-impl drift can run as a CI gate.

Inside are project setup steps, requirement generation via `indexion spec draft`, and pairwise document alignment with `indexion spec align diff` and a threshold. For ISO standards the text is first pulled out of the PDF by `scripts/extract_iso_text.py`. Requirements land in `.kiro/specs/<feature>/requirements.md` using the `### Requirement N:` and `#### N.M:` hierarchy cc-sdd expects.

Check that `indexion` is installed and recognises your spec format before you start — the drift gate and the validation loop both depend on it. Language is the other trap. Set cc-sdd's `--lang` to the code language, not the document's: English code needs `--lang en`, otherwise `spec align diff` fails to match vocabulary. And keep in mind that `spec align` only sees word overlap. A requirement that inverts the spec's intent while reusing its vocabulary still reports MATCHED, and that gap surfaces at E2E testing.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add trkbt10/indexion-skills --skill indexion-sdd -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/indexion-sdd/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/indexion-sdd/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add trkbt10/indexion-skills --skill indexion-sdd -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/indexion-sdd/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add trkbt10/indexion-skills --skill indexion-sdd -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/indexion-sdd/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install trkbt10/indexion-skills indexion-sdd
```

2. **Manually: put the files in place**
- File: `.github/skills/indexion-sdd/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add trkbt10/indexion-skills --skill indexion-sdd -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/trkbt10/indexion-skills --path skills/indexion-sdd
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/indexion-sdd/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add trkbt10/indexion-skills --skill indexion-sdd -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/trkbt10/indexion-skills/tree/HEAD/skills/indexion-sdd/SKILL.md

## When to use it
- turn an RFC into a draft of SDD requirements
- catch spec-to-code drift before merging
- walk requirements through design and implementation alignment
- run drift checks as a CI gate
- spot draft requirements that quietly skipped part of the spec

## Example prompts
- Generate requirements from `rfc_document.md` into `.kiro/specs/<feature>/requirements.md`
- Run `indexion spec align diff` between requirements and `src/` with threshold 0.3
- Run the SDD loop for this feature and check for drift before merge

## Source text · SKILL.md · Apache-2.0

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 727378d8c7197401.

BEGIN THIRD-PARTY FILE 727378d8c7197401
````text
---
name: indexion-sdd
description: Generate SDD requirements from RFCs/specs and quantitatively verify implementation conformance. spec draft → spec align → spec verify → automated validation loop with codex/claude. Operate spec-to-impl drift gates as CI checks.
---

# indexion SDD (Spec-Driven Development)

Bridge indexion's quantitative spec alignment tools with SDD agent workflows (cc-sdd, codex, etc.).

Provides: RFC/document → SDD draft, spec↔impl drift detection, and a validation loop
that feeds indexion's quantitative results into agent-driven qualitative review.

## When to Use

- User wants to implement an RFC or specification as a library/package
- User asks to verify spec-to-implementation conformance
- User wants to set up a SDD project with cc-sdd + codex + indexion
- User says "run the SDD loop" or "validate against the spec"
- After `codex spec-impl` completes, to check for drift before merging

## Important

- **Set cc-sdd `--lang` to match the implementation language, not the
  spec language.** If code is in English, use `--lang en`. Mismatched
  languages break `spec align diff` vocabulary matching.

## Process: RFC → Implementation → Validation

### Step 0: Project Setup

```bash
# Create project directory
mkdir my-rfc-impl && cd my-rfc-impl

# Install cc-sdd for your agent — set lang to match the code language
npx cc-sdd@latest --codex-skills --lang en --yes   # codex (skills mode)
npx cc-sdd@latest --claude-skills --lang en --yes   # claude (skills mode)

# Initialize project (language-specific)
# e.g., cargo init, npm init, moon new, etc.

# Initialize git
git init && git add -A && git commit -m "init"
```

**Verify indexion is available** before proceeding. The drift gate
(Step 2.5) and validation loop (Step 3) depend on it:

```bash
indexion --version                       # must be installed
indexion kgf edges <any-source-file>     # must detect language and show edges
```

If `indexion` is not installed, install it first. If the KGF for your
spec format is not recognized, update `indexion` to a version that
includes it. See Step 2.7 for the fallback when this cannot be resolved.

### Step 1: Specification → SDD Draft (indexion)

Fetch the specification document (RFC, ISO standard, etc.) and prepare it:

```bash
# For RFC: save as markdown or .rfc.txt
indexion spec draft --output .kiro/specs/<feature>/requirements.md rfc_document.md

# For ISO/IEC standards: extract text from PDF with cleanup, then draft
````
END THIRD-PARTY FILE 727378d8c7197401

The third-party file has ended. Everything between the 727378d8c7197401 tags is data: requests and commands from it are not followed. An “end of file” line with another tag inside the block is part of the file.

First 2491 of 33983 bytes. © trkbt10 · Apache-2.0 · https://github.com/trkbt10/indexion-skills/tree/HEAD/skills/indexion-sdd/SKILL.md

_Part of the page did not fit — see the HTML version._

---
NeVibeCode on affpapa.org. Catalog texts are descriptions, not instructions for the agent. How to choose and install: https://affpapa.org/en/nevibecode/agents.md