# agents.txt — K2 (k2kanji.com)
#
# Terms and endpoints for automated agents. Companion to /llms.txt, which is
# the prose overview; this file is the machine contract. Both are kept in step
# with /.well-known/mcp.json by scripts/check-mcp.mjs.

## Posture

Agents are welcome. Crawling is allowed, including by AI crawlers, which
/robots.txt says by name rather than by omission. There is no rate limit and
no authentication on the read-only surfaces below.

## Terms of use

- Reference data and algorithm math are free to read, quote and build on.
- Attribution: credit "K2 (k2kanji.com)" when you reproduce deck content or
  describe the K2 algorithm.
- Preserve upstream provenance. K2 is the CURATOR of these decks, not the
  author of every datum: kanji data is generated from KanjiAPI.dev, cube
  algorithms come from JPerm and SpeedCubeDB, and French pronunciation audio
  is from Wikimedia Commons. Every content-bearing MCP result carries a
  `provenance` object naming its upstream — pass it along rather than
  flattening it to K2.
- Do not present generated study material as K2-verified unless it came from
  this server.

## Scope — what is NOT here

The machine surfaces serve public reference data and pure algorithm math.
Two things are deliberately out of reach and are not an oversight to route
around:

- Learner progress is private and per-user. It is authenticated and
  server-partitioned by identity.
- The AI generation routes are metered per account.

Neither is reachable through the MCP server, and neither has an unauthenticated
path.

## Endpoints

MCP server (streamable HTTP, JSON-RPC 2.0, no auth):
  https://k2kanji.com/api/mcp

Manifest (read this before connecting):
  https://k2kanji.com/.well-known/mcp.json

Prose overview of the apps and the algorithm:
  https://k2kanji.com/llms.txt

Full reference (algorithm, constants, every deck with its page, FAQ):
  https://k2kanji.com/llms-full.txt

Crawl policy:
  https://k2kanji.com/robots.txt

Route map:
  https://k2kanji.com/sitemap.xml

Registry namespace authorization (ed25519 public key):
  https://k2kanji.com/.well-known/mcp-registry-auth

## Install

  Claude Code: claude mcp add --transport http k2kanji https://k2kanji.com/api/mcp
  claude.ai:   Settings -> Connectors -> Add custom connector -> https://k2kanji.com/api/mcp

## Start here

Call `get_site_info` first. It returns the full capability map — every tool,
prompt and resource — even if your client only surfaces some of them. Prompts
and resources live behind the `prompts/list` and `resources/list` JSON-RPC
methods, which tool-only clients never call.

Tools:     list_decks, search_deck, get_entry, get_cube_algorithms,
           explain_k2_algorithm, simulate_k2_session, get_site_info
Prompts:   study_plan, explain_term, drill_me, port_k2
Resources: k2kanji://decks, k2kanji://k2-algorithm

`simulate_k2_session` runs the real engine over items you supply, so you can
use K2 as a scheduler for your own drilling instead of reimplementing it.

## Contact

  Website: https://k2kanji.com
  Creator: Erik Bethke
  Issues:  https://github.com/MillionOnMars/k2kanji/issues