Capsule

Compact, source-linked context packs for coding agents.

Docs · Quickstart · Commands

MCP gives agents tools. Skills give agents procedures. Capsules give agents compact project context.

Large repositories make coding agents burn tokens rediscovering the same files, decisions, conventions, and setup details over and over. Capsule targets a 50–70% reduction in repeated repository-discovery context for large, multi-session agent work.

Install

No install required — run directly with npx (always gets the latest version):

npx capsulectx init

Or install globally with your package manager:

# npm
npm install -g capsulectx

# pnpm
pnpm add -g capsulectx

# yarn
yarn global add capsulectx

# bun
bun add -g capsulectx

Keep it up to date:

npm install -g capsulectx --prefer-online

Tip: npx is the easiest option — it always runs the latest published version with no manual update step.

Quickstart

npx capsulectx init

Capsule scans your repo, optionally enriches capsules with AI (using your installed Claude CLI, API keys, or a generated prompt for any browser-based AI), and creates:

.capsules/
  index.md
  architecture.md
  setup.md
  api.md
  data.md
  ui.md
  testing.md
  deployment.md

Each capsule is a Markdown file with source fingerprints in JSON frontmatter:

---json
{
  "name": "api",
  "sources": ["src/api/**"],
  "fingerprints": { "src/api/users.ts": "sha256:..." },
  "updated_at": "2026-06-20T14:00:00.000Z"
}
---

# API Capsule

## Purpose

Request handlers, routes, controllers, and service boundaries.

## Key Files

- `src/api/users.ts`: source file matched by this capsule.

## Decisions

- Record stable decisions here so future agents do not rediscover them.

Agents read .capsules/index.md, choose the relevant capsule, check staleness, then inspect only the source files that actually matter.

Commands

MCP Server

Capsule ships an MCP server so Claude Code and other MC

... View full README on GitHub