Osdev Wiki MCP server

osdev-wiki-mcp

The OSDev wiki, offline and searchable, for your AI agent.

<!-- mcp-name: io.github.0xmortuex/osdev-wiki-mcp -->

wiki.osdev.org is the reference for hobby operating-system development. It covers descriptor tables, paging, interrupt controllers, timers, ACPI, disk controllers, bootloaders and toolchains. Agents writing kernel code tend to reconstruct these details from memory and get bit layouts wrong. They also can't browse the wiki themselves, because it sits behind a bot challenge.

osdev-wiki-mcp downloads the wiki's public archive once, indexes it locally with SQLite full-text search, and gives the agent tools to search it, read a page or just one section of it, and follow links.

What it looks like

This is real output, from the 2025-12-30 dump:

> wiki_search("PIT", limit=3)
1. Programmable Interval Timer *
   The Programmable Interval Timer ([PIT]) chip (Intel 8253/8254) basically consists of an oscillator…
2. PC Speaker
   …When the [PIT] interrupts you, you need to program [PIT] timer 2 so that…
3. APIC Timer
   …Real Time Clock, TimeStamp Counter, [PIT] or even polling CMOS registers. In this tutorial…

> wiki_page("IDT", section="Gate Descriptor", max_chars=900)
# Interrupt Descriptor Table
https://wiki.osdev.org/Interrupt_Descriptor_Table · last edited 2025-06-05 · categories: X86 CPU, Interrupts
('IDT' redirects to 'Interrupt Descriptor Table'; 'Gate Descriptor' appears 2 times; showing
section 4 under 'Structure on IA-32'. Also: section 8 under 'Structure on x86-64')

### Gate Descriptor

Each entry in the table has a complex structure:

Gate Descriptor (32-bit):
63..48 | 47 | 46..45 | 44 | 43..40 | 39..32
Offset 31..16 | P | DPL 1..0 | 0 | Gate Type 3..0 | Reserved
31..16 | 15..0
Segment Selector 15..0 | Offset 15..0

- Offset: A 32-bit value, split in two parts. It represents the address of the entry point ...
[... section truncated]

[Cut at max_chars=900; the full text is 1567 chars. Call again with max_chars=1

Notice what the output does for the agent:

as aliases of their target, so an abbreviation finds the right page first.

• Abbreviations work. "PIT" and "IDT" are wiki redirects, and redirects are indexed

as HTML tables. These are rendered as one row per line, with bit ranges shown as 63..48.

• Bit-layout tables stay readable. The wiki draws descriptor and page-table layouts

where the other copy is.

• Ambiguity is reported. When a heading appears twice on a page, the agent is told

• Truncation explains itself. A cut-off result says exactly what to call next.

Install

pip install osdev-wiki-mcp
osdev-wiki-mcp --update          # one-time: download (~5 MB) and index (~15 s)
claude mcp add osdev-wiki -- osdev-wiki-mcp

You can skip --update. The agent can call wiki_update itself: every other tool tells it to when there's no index yet.

The index (about 18 MB) lives in %LOCALAPPDATA%\osdev-wiki-mcp on Windows, ~/Library/Application Support/osdev-wiki-mcp on macOS, and $XDGDATAHOME/osdev-wiki-mcp (or ~/.local/share/osdev-wiki-mcp) elsewhere. Set OSDEVWIKIDIR to put it somewhere else. Python 3.10+ is required, with SQLite FTS5. python.org builds, uv-managed builds and most distro builds include FTS5, and the server tells you if yours doesn't.

Tools

Shortened. The full README is on GitHub.