What is OpenSpec?
OpenSpec is a MCP server by Fission-AI that spec-driven development that aligns humans and AI assistants before coding starts. It is listed under Developer tools and has 71,000 GitHub stars.
| Type | Mcp server |
|---|---|
| Author | Fission-AI |
| Repository | Fission-AI |
| Popularity | 71,000 GitHub stars |
| Category | Developer tools |
| Security | Low risk (92/100) |
| Rank | #11 of 4,418 MCP servers; #5 in Developer tools |
| Runs | Not stated |
Is OpenSpec safe to install?
OpenSpec scores 92/100 on the MCPMods security check: Low risk. No checks raised a concern. It passed 4 of 6 checks.
MCP server results come from listing signals: who publishes it, where your data goes and what it can do. The code itself is not scanned yet.
| Check | Result |
|---|---|
| Community-built server | Note |
| Where data goes is not stated | Note |
| No credentials mentioned | Pass |
| Read-only by description | Pass |
| No code execution | Pass |
| Source on GitHub | Pass |
How do I install OpenSpec?
- Find the launch command. The README says how the server starts (npx, uvx, docker or a remote URL) and which API keys it needs.
https://github.com/Fission-AI
- Add it to Claude Code. Replace the part after -- with the command from the README. Remote servers use --transport http with a URL.
claude mcp add openspec -- <command from README> claude mcp add --transport http openspec <server-url>
- Check it connected. This lists your MCP servers and their status.
claude mcp list
Or ask Claude to set it up
Paste this into Claude Code and it installs OpenSpec for you:
Add the "OpenSpec" MCP server from https://github.com/Fission-AI to Claude Code. Read its README for the launch command and any API keys I need, run claude mcp add, then check that it connects.