# Kelvin — power-electronics component catalogue for AI agents

> Deterministic parts librarian over the TAS catalogue: about 1.4 million real parts across MOSFETs, diodes,
> capacitors, resistors, magnetics (inductors, transformers, chokes, ferrite beads), controllers,
> IGBTs, BJTs, varistors/TVS, analog ICs, timing devices and connectors. No LLM inside: every
> answer is computed by Kelvin's C++ engine, with datasheet links and per-parameter verdicts.

## Use it from an AI (Model Context Protocol, no sign-in)

- MCP endpoint (Streamable HTTP): https://kelvin.openconverters.com/mcp
- Server card: https://kelvin.openconverters.com/.well-known/mcp/server-card.json
- Claude Code:  claude mcp add --transport http kelvin https://kelvin.openconverters.com/mcp
- Codex CLI / Gemini CLI / Cursor / VS Code / ChatGPT connectors / any MCP client: add a remote
  server with the URL above (transport: streamable-http, authentication: none).

## Tools (all read-only)

- list_families — the 12 component families; which have a selector and a cross-reference.
- describe_family — exact filterable field names for one family. Call before search_parts.
- search_parts — parametric search: numeric ranges, categorical values, MPN, manufacturer, facets.
- part_details — one part by MPN with its full catalogue record and datasheet links.
- recommend_parts — rank real parts for a designRequirements block (deterministic selector).
- cross_reference — scored substitutes for an MPN, with per-parameter pass/warn/fail.
- spec_distribution — histogram of one spec over a filtered slice (what is actually available).

## Conventions that matter when answering

- Values are SI base units (F, H, V, A, Ω, Hz, s); tolerance is a fraction.
- A part whose record does not state a field is excluded by a filter on it; absence is never 0.
- If the original part's record is incomplete, no substitute is graded "recommended".
- Results are capped: search returns at most the first 1000 matches; narrow the filters instead of paging.
- Licence: data CC BY 4.0 (attribute "Kelvin parts catalogue, OpenConverters"), code MIT. Check the datasheet before relying on a value.
- Fair use: the server rate-limits per client. Do not crawl; ask specific questions.

## Source and code

- Web app: https://kelvin.openconverters.com
- Code: https://github.com/OpenConverters/Kelvin
- Per-part pages (HTML + JSON-LD): https://kelvin.openconverters.com/part/<family>/<mpn> (append .json for JSON)