promptbranch-portal

PromptBranch is a local-first prompt library for creating, organizing, testing, and improving AI prompts. The desktop app, CLI, and MCP server use the same library, so users can work in the interface they prefer without copying prompts between tools. The library stays on the user's computer, and browsing, editing, versioning, and search work without an account or internet connection.

The product supports the whole prompt lifecycle, from first draft to proven version. It provides branching version history with sequential versions, branches, diffs, and change notes. Users can run prompts with one or more connected AI models, compare results, and record ratings and costs. Evidence such as ratings, run logs, multi-model runs, and an LLM judge show which version performs.

PromptBranch includes a sharing portal for publishing immutable prompt snapshots with unguessable links that can be revoked later. Users can embed active shares on a website using a provided HTML snippet, or link to a public Markdown file that readers can import into their own library. The CLI and MCP server let coding agents fetch prompts, report results, and suggest variations, with user approval required.

Multi-device sync keeps the library in sync between the user's own desktop devices on a local network or VPN. Model runs, model catalog refreshes, publishing a share, and fetching a public Markdown file need a network connection. API keys remain on the device where they are added.