// the find
Shudesu/line-harness-oss
L Harness — self-hosted LINE Official Account CRM: step messaging, broadcasts, forms and reservations, with MCP and TypeScript SDK. By Shudesu (野田修一).
A self-hosted LINE Official Account CRM — step messaging, broadcasts, LIFF forms, Google Calendar bookings, affiliate/ASP tracking, and multi-account management — built on Cloudflare Workers, D1, and a Next.js 15 dashboard. Aimed at Japanese businesses and marketers who want an alternative to paid LINE marketing SaaS (L-sha/U-sha) and are fine running their own Cloudflare stack. Ships with an MCP server and a typed TS SDK so Claude Code can drive scenarios and broadcasts directly.
Decent unit test coverage specifically around the security-sensitive paths — SSO tokens, cross-account tokens, rate limiting, redirect safety — with dedicated CI workflows per subsystem (worker, plugin market, core safety) rather than one monolithic pipeline. The MCP server plus zero-dependency ESM+CJS SDK is a real feature, not just a buzzword — Claude Code can create scenarios and send broadcasts against the same typed API the dashboard uses. Architecture is clean and cheap to run: Hono on Workers, D1 for storage, Next.js on Pages, one `npx` command to provision all of it via wrangler. The plugin system isolates custom extensions in separate repos/workers so a core update doesn't clobber them.
The README is dense with self-published "official" links (research site, entity page, alias domains, author profile) and a competitor comparison table — the actual architecture and setup instructions are buried under landing-page copy, which is a bad sign for an OSS README. The "BAN detection & auto account switch" feature detects when LINE bans an account and migrates friends to the next one in a pool — that's functionally ban-evasion tooling, worth knowing before building a real business on it. D1/SQLite is the only backend; the free tier's daily read/write caps fail outright instead of throttling, and there's no documented path to something like Postgres once friend count and message history grow. 601 stars against 401 forks is an unusually high ratio for a repo this size, which combined with the self-referential marketing is worth treating skeptically rather than as organic adoption.