@nordio/server-kit

The shared library every MCP server reuses — so no server hand-rolls plumbing (guideline hard rule 12).

What exists today

• createMcpServer(opts) — build a client-agnostic server from ToolDef[] (title, agent-written description, Zod inputSchema, annotations, handler with { mock, log } context, error-to-isError wrapping, automatic per-call instrumentation with duration + redacted args), optional ResourceDef[] (<domain>://reference manuals — query syntax, field maps, examples) and optional PromptDef[] (registered canonical workflows, e.g. monthly_review)
• Typed annotation vocabulary: readOnlyLocal · readOnlyExternal · writeCreate · writeUpdate · writeDelete · writeIrreversible — semantics reasoned once, one-liner per tool
• runStdio(server) — stdio transport (local dev via .mcp.json, .mcpb packaging)
• createHttpApp(makeServer) — Streamable HTTP via Express (remote/Vercel; stateless, fresh server+transport per request; add OAuth middleware in front of POST /mcp before production)
• createLogger() — structured JSON logging to stderr with redaction by key AND by value-shape (long opaque strings under innocent keys), and child loggers
• Cache — volatility-aware caching ({ immutable } → cache hard · { ttlMs } → expire · {} → no-cache), hit/miss/entries metrics, injectable clock (ported from bankingMCP's TtlCache)
• FileTokenStore — per-account AES-256-GCM encrypted token store under the state dir (§2c; key in a 0600 keyfile), get/set/delete/list, account names hashed; TokenStore interface
• generatePkce · runLoopbackOAuth · exchangeCode · refreshTokens — OAuth 2.1 Authorization-Code + PKCE loopback for local tools (the gmail-cli/banking pattern, generalized)
• Ledger — append-only JSONL audit ledger (§2c): record/recent (for undo), seen (idempotent re-runs), hashPayload, redactForModel (LLM-safe reads) — the write-safety core

Planned (not yet implemented — don't reference these as available)

• Multi-tenant / remote auth — per-client consent + fail-closed OAuth middleware in front of POST /mcp (the commercial / service-operation tier; the local oauth + FileTokenStore above cover the single-user default)
• OS-keychain token store — Keychain/DPAPI/libsecret backing, stronger than the file+0600 baseline
• Correlation ids end-to-end
• Entitlement checks (for the optional commercialization layer)
• Out-of-band approval for irreversible remote writes (the local Ledger + --confirm covers the CLI/local path)
• Log forwarding to the client (capabilities: {logging} + sendLoggingMessage) — port from bankingMCP

Distribution

Published to public npm as @nordio/server-kit on every factory tag (release.yml). Consumers npm install @nordio/server-kit (no registry config) and depend on a version range — Dependabot delivers updates as PRs. Vendoring into the project's own workspace remains an option for fully self-contained scaffolds. Improvements flow back to the factory, not into forks.