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.