Connect the server

Your AI client starts the server itself, with uv: it runs uvx cpu-perf, which fetches the release and starts it. Add that command to your client once, as below; run in a terminal, it only waits for a client. (pip install cpu-perf works too and gives the same cpu-perf command.)

The first start downloads its dependencies, which can take longer than some clients wait for a new server. Run uvx cpu-perf --version once in a terminal first, and every client after that starts it in about a second.

Every client above starts the server on your own machine; there is nothing to host. Claude.ai, the mobile apps and ChatGPT on the web connect only to servers on the internet, not to a program on your computer, so they cannot use it yet.

The server answers from the repository immediately. In the background it fetches the linked sources into a local library:

• where: ~/.local/share/cpu-perf on Linux, ~/Library/Application Support/cpu-perf on macOS, %LOCALAPPDATA%\cpu-perf on Windows, or CPU_PERF_DATA_DIR;
• how long: a few minutes to a quarter of an hour, depending on the network and the large manuals; the crawl resumes where it stopped if the client closes the server;
• how big: one SQLite file of passages, a keyword index and embeddings, a few hundred megabytes at most; the downloaded files themselves are not kept;
• what it skips: very large PDFs are indexed up to a page cap and the rest is read on demand; scanned PDFs, compressed PostScript and videos have no text to index (videos keep their title and description).

To build it in the foreground with progress, run cpu-perf index; cpu-perf status --detail lists every source with its state.

Several MCP clients (Claude Desktop, Claude Code and Cursor at once, say) share one library. Every few minutes one of them, whichever holds an operating-system lock on the data folder, does the upkeep: it fetches sources that are new, due for a refresh or due for a retry, embeds passages that have no vector, and brings a library built by an older release up to date in place; a source is fetched again only when a release improves how its kind of document is read (this one rejoins words PDFs hyphenate across lines). A refresh that fails keeps the copy already in the library, unless the document is gone. The lock is released by the system if that client exits or crashes, and the work pauses while requests arrive.

Some publishers (ACM, IEEE, parts of the Intel and Arm portals) refuse automated clients or render their documents only in a browser. Those sources are reported as blocked or partial, with the list's own link notes on why, and the answer points the reader to the link instead. Coverage is reported as it is, never padded.

Semantic search uses the small static embedding model potion-base-8M, downloaded once. Without it (offline, or CPU_PERF_EMBED_MODEL=none) the library falls back to keyword search alone.