spec-agent 0.1.2

Auto-generate an Obsidian knowledge wiki from every git push, powered by Claude

spec-agent

Auto-generate an Obsidian knowledge wiki from every git push — powered by Claude.

Every time you push code, spec-agent reads the diff, classifies the change, and writes a structured spec document into your Obsidian vault. Over time, your vault becomes a living, visually-navigable graph of everything you've ever built.

Inspired by Andrej Karpathy's LLM Wiki pattern: the LLM acts as a compiler (raw commits → structured wiki), not a retrieval engine. No RAG, no embeddings — just well-organized markdown with [[wikilinks]] that Obsidian renders as a knowledge graph.

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How It Works

git push
  └── ~/.git-hooks/post-push        ← global hook, fires on every repo
        └── spec-agent run           ← Python CLI
              └── Claude (tool-use)  ← agentic loop
                    ├── classify_commit
                    ├── search_wiki       ← finds related existing pages
                    ├── read_wiki_file    ← reads context before updating
                    ├── write_wiki_file   ← creates or updates spec
                    └── update_index      ← appends row to index.md

The agent:

1. Classifies the commit type (feature, bug, refactor, arch, chore)
2. Searches your vault for related pages to link to
3. Writes an adaptive spec using the appropriate template
4. Updates index.md — the master log that Claude reads at session start

Chore commits are skipped. Bot branches (dependabot/*, renovate/*) are skipped. Tiny commits (below a configurable character threshold) are skipped.

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Features

• Zero friction — fires automatically on every git push, no developer action needed
• Adaptive templates — selects the right format based on commit type
  • feature → full spec (summary, problem, implementation, files, open questions)
  • bug → short report (root cause, fix applied)
  • refactor → brief note (what changed, why, before/after)
  • arch → ADR format (context, decision, consequences, alternatives)
• Accurate [[wikilinks]] — searches vault for existing pages before writing, so links are real
• Living index — index.md is a table of every spec ever written; share it with Claude at session start to give it full project memory
• Obsidian graph — concepts referenced by many specs become visual hubs after 10+ specs
• Works on every repo — one global hook installation covers all your projects

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Prerequisites

• Python 3.11+
• An Anthropic API key — get one here
• Obsidian — download here (free)
• Git 2.9+ (for core.hooksPath support)

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Installation

From PyPI (recommended)

pip install spec-agent

From source

git clone https://github.com/visheshchaitanya/spec-agent.git ~/.spec-agent
pip install -e ~/.spec-agent

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Setup

1. Set your API key

export ANTHROPIC_API_KEY="sk-ant-..."

Add this to your shell profile (~/.zshrc, ~/.bashrc, or ~/.zshenv) to make it permanent:

echo 'export ANTHROPIC_API_KEY="sk-ant-..."' >> ~/.zshrc

2. Initialize your vault

spec-agent init --vault ~/Documents/dev-wiki

This creates the vault directory structure and writes a default ~/.spec-agent/config.yaml.

Then open ~/Documents/dev-wiki as a vault in Obsidian (File → Open vault as folder).

3. Install the global git hook

spec-agent install-hook

This creates ~/.git-hooks/post-push and sets git config --global core.hooksPath ~/.git-hooks. The hook fires on every push in every repository on your machine.

4. Push anything to test

cd ~/any-repo
git push
# → spec-agent fires in the background
# → spec appears in ~/Documents/dev-wiki

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Configuration

Config lives at ~/.spec-agent/config.yaml:

vault_path: ~/Documents/dev-wiki
model: claude-sonnet-4-6
ignored_repos: []           # list of repo names to skip entirely
ignored_branches:
  - dependabot/*
  - renovate/*
min_commit_chars: 50        # skip pushes where total commit message length is below this

Key	Default	Description
vault_path	~/Documents/dev-wiki	Absolute path to your Obsidian vault
model	claude-sonnet-4-6	Anthropic model to use
ignored_repos	[]	Exact repo names to never process
ignored_branches	[dependabot/*, renovate/*]	Glob patterns — matching branches are skipped
min_commit_chars	50	Skip pushes where total commit message length is below this (filters "wip", "fix typo")

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Vault Structure

~/Documents/dev-wiki/
├── index.md                    ← master log — give this to Claude at session start
├── features/
│   ├── alert-ingestion.md
│   └── auth-system.md
├── bugs/
│   ├── fix-status-migration.md
│   └── fix-null-pointer.md
├── refactors/
│   └── extract-auth-middleware.md
├── concepts/                   ← auto-created graph hubs when first referenced
│   ├── clickhouse.md
│   └── jwt.md
└── projects/
    └── my-app.md

index.md — your project memory

index.md is a markdown table of every spec ever written:

# Dev Wiki — Index

| Date | Type | Title | Project | Link |
|------|------|-------|---------|------|
| 2026-04-07 | bug | Fix status migration | my-app | [[bugs/fix-status-migration]] |
| 2026-04-05 | feature | Alert ingestion pipeline | my-app | [[features/alert-ingestion]] |

Paste the contents of index.md at the start of any Claude session — Claude immediately knows everything you've built across all projects.

Spec frontmatter

Every generated spec has YAML frontmatter:

---
type: feature
project: my-app
date: 2026-04-07
commit: a3f9c12
status: shipped
---

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Giving Claude context at session start

Paste this into your Claude session to give it full project memory:

Here is my dev wiki index — everything I've built:

<paste contents of ~/Documents/dev-wiki/index.md>

I'm working on <task>. Based on the index, what related specs should I look at?

Claude can then ask you to paste specific spec files for deeper context.

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CLI Reference

spec-agent [COMMAND] [OPTIONS]

Commands:
  run           Run the agent (called automatically by git hook)
  init          Initialize vault directory and write config
  install-hook  Install global git post-push hook
  config-get    Read a config value (used internally by hook)

spec-agent run

Options:
  --repo TEXT        Repository name (required)
  --branch TEXT      Branch that was pushed (required)
  --messages TEXT    Newline-separated commit messages (required)
  --diff-file TEXT   Path to temp file containing the git diff (required)
  --config TEXT      Path to config.yaml [default: ~/.spec-agent/config.yaml]

spec-agent init

Options:
  --vault TEXT  Path to Obsidian vault directory (required)

spec-agent install-hook

No options. Installs ~/.git-hooks/post-push and sets the global git hooks path.

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Manual run (without pushing)

You can run the agent manually against any repo:

DIFF_FILE=$(mktemp /tmp/spec-agent-diff.XXXXXX)
git diff HEAD~1..HEAD | head -c 50000 > "$DIFF_FILE"

spec-agent run \
  --repo "$(basename $(pwd))" \
  --branch "$(git rev-parse --abbrev-ref HEAD)" \
  --messages "$(git log HEAD~1..HEAD --format='%s')" \
  --diff-file "$DIFF_FILE"

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Per-repo opt-out

To exclude a specific repo from spec generation, add its name to ignored_repos in ~/.spec-agent/config.yaml:

ignored_repos:
  - my-private-repo
  - dotfiles

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Development

Requirements

git clone https://github.com/visheshchaitanya/spec-agent.git
cd spec-agent
pip install -e ".[dev]"

Run tests

pytest

Run tests with coverage

pytest --cov=spec_agent --cov-report=term-missing

All tests use temporary directories — no vault or API key required.

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Architecture

Tool-using agent loop

The agent runs an Anthropic messages.create loop until stop_reason == "end_turn":

client.messages.create(tools=TOOL_DEFINITIONS, ...)
  → stop_reason == "tool_use"
      → dispatch tool, collect results
      → append assistant + user messages
      → loop
  → stop_reason == "end_turn"
      → done

Tools

Tool	Purpose
classify_commit	Agent classifies diff type and extracts concepts (no-op server-side — agent reasons internally)
search_wiki	Full-text search across vault using grep -r — finds related pages for wikilinks
read_wiki_file	Reads existing spec file — enables update mode instead of duplicate creation
write_wiki_file	Writes markdown to vault; mode=update appends a dated changelog section
update_index	Appends row to index.md master log

Diff safety

Git diffs larger than 50,000 characters are truncated before being passed to the agent. The diff is passed via a temp file (not shell arguments) to avoid escaping issues with special characters.

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Roadmap

• GitHub webhook / cloud daemon (replace local hook with HTTP POST)
• Multi-agent parallel processing (Classifier + Writer + Linker)
• Obsidian Dataview dashboards
• Per-project vault paths
• Slack/email notifications on spec creation

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Contributing

Pull requests welcome. Please:

1. Fork the repo and create a branch from main
2. Add tests for any new behavior
3. Ensure pytest passes
4. Open a pull request

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License

MIT — © 2026 Vishesh Chaitanya