Sindri Extension Guide

Sindri supports extensions for both V2 (Bash/Docker) and V3 (Rust CLI) platforms. Before proceeding with extension creation, you need to choose which platform you're targeting.

Version Differences at a Glance

Aspect	V2	V3
Implementation	Bash (~52K lines)	Rust (~11.2K lines)
Extension Directory	`v2/docker/lib/extensions/`	`v3/extensions/`
Schema Location	`v2/docker/lib/schemas/extension.schema.json`	`v3/schemas/extension.schema.json`
CLI	`./v2/cli/extension-manager`	`sindri extension`
Install Methods	6 (mise, apt, binary, npm, script, hybrid)	7 (adds npm-global)
Categories	11	12 (different set)
VisionFlow	Supported	Not available

V2 Categories

base, agile, language, dev-tools, infrastructure, ai, database, monitoring, mobile, desktop, utilities

V3 Categories

ai-agents, ai-dev, claude, cloud, desktop, devops, documentation, languages, mcp, productivity, research, testing

When to Choose V2

VisionFlow workflows - vf-* extensions only available in V2
Proven stability - Battle-tested codebase
Docker-first - Deep Docker/container integration
Team familiar with Bash - V2 scripts are all Bash

When to Choose V3

New projects - Modern architecture
Windows support - Native Windows binaries
Performance - 10-50x faster CLI operations
Advanced collision handling - Smart merge strategies for cloned projects
Project-context merging - CLAUDE.md file management

Required Action: Choose Version

Before creating an extension, use AskUserQuestion to determine:

Which Sindri version (V2 or V3)?
Basic extension details (name, category, purpose)

Then delegate to the appropriate specialist skill:

V2: Use /extension-guide-v2 skill
V3: Use /extension-guide-v3 skill

Slash Commands

Command	Description
`/extension-guide`	This router (choose version first)
`/extension-guide-v2`	V2-specific extension guide
`/extension-guide-v3`	V3-specific extension guide

Quick Decision Tree

Creating an extension?
    │
    ├── Need VisionFlow (vf-*)?
    │   └── V2 only
    │
    ├── New AI/Claude tool?
    │   └── V3 recommended (better categories, collision handling)
    │
    ├── Language runtime (Node, Python, etc.)?
    │   └── Either works (V3 preferred for new projects)
    │
    └── Windows support needed?
        └── V3 only

Shared Features (Both V2 and V3)

Both versions support the capabilities system for advanced extensions:

project-init - Commands to initialize projects
auth - API key and CLI authentication
hooks - Lifecycle hooks (pre/post install, pre/post project-init)
mcp - Model Context Protocol server registration
features - Feature flags for advanced functionality

Most extensions don't need capabilities - they're for extensions that manage project setup (like Claude Flow, Agentic QE, Spec-Kit).

Next Step: Ask the user which version they need, then invoke the appropriate specialist skill.

extension-guide