netris-nestri/packages/core/CLAUDE.md

packages/core — domain modules

Structure

Every domain module lives in packages/core/src/<parent>/ as either a top-level namespace or a nested sub-module:

src/<parent>/
  ├── <parent>.sql.ts        # (optional) Drizzle table for the parent entity
  ├── index.ts               # Parent namespace (e.g. User, Game, Team)
  ├── <child>.sql.ts         # Sub-module table (e.g. fingerprint.sql.ts)
  └── <child>.ts             # Sub-module namespace (e.g. export namespace Fingerprint)

Sub-modules nested under parents

File	Namespace	Why
user/linked-account.*	LinkedAccount	A user's OAuth/gaming identities
user/fingerprint.*	Fingerprint	SSH key fingerprints
game/download.*	GameDownload	Per-host game depot downloads
user/library.*	Library	User's owned games with playtime
team/member.*	Member	Team membership with role
game/depot.*	Depot	Platform-specific game content depots
steam/enrolment.*	Enrolment	Which host holds a Steam token for whom

Existing top-level modules: user/, team/, game/, pairing-code/, steam/, auth/, db/.

A parent may own no table of its own and still have sub-modules that do: steam/index.ts is reusable fn() functions with no .sql.ts beside it, while steam/enrolment.* is a full pair.

Pattern: .sql.ts (Drizzle Table)

// src/<module>/<module>.sql.ts
import { pgTable, text, boolean, jsonb, uniqueIndex, index, pgEnum } from 'drizzle-orm/pg-core';

import { id, timestamps, ulid } from '../db/types.js';

// Enum (only if needed — co-located with its table)
export const SomeEnum = pgEnum('some_enum', ['a', 'b']);

// FK imports — use the sql.ts files, never the index.ts (avoids circular deps)
import { UserTable } from '../user/user.sql.js';

export const SomeTable = pgTable(
	'some_table',
	{
		...id, // char(30) PK, prefix: som_
		...timestamps, // time_created, time_updated, time_deleted (all utc)

		// FK column — always use ulid() + .references()
		userId: ulid('user_id')
			.notNull()
			.references(() => UserTable.id, { onDelete: 'cascade' }),

		// Scalar columns
		name: text('name').notNull(),
		email: text('email'), // nullable = omit .notNull()
		flag: boolean('flag').notNull().default(false),
		metadata: jsonb('metadata').$type<{}>(), // JSON blob

		// Enum column
		provider: SomeEnum('provider').notNull()
	},
	(t) => [
		uniqueIndex('some_table_provider_unique').on(t.provider, t.providerAccountId),
		index('some_table_sync_idx')
			.on(t.userId)
			.where(sql`${t.localValue} is distinct from ${t.remoteValue}`),
		index('some_table_user_idx').on(t.userId)
	]
);

DB types (src/db/types.ts)

Helper	Output
ulid(name)	char(30) — for PKs and FKs
id	{ id: ulid('id').primaryKey().notNull() } — spread as ...id
utc(name)	timestamp with time zone
timestamps	{ timeCreated, timeUpdated (auto), timeDeleted }

Naming conventions

• Table name: snake_case (e.g. linked_account, team_member)
• Column name: snake_case (e.g. user_id, provider_account_id, time_created)
• TypeScript field names: camelCase matching the column (drizzle maps them)
• Index names: {table}_{column(s)}_unique / {table}_{column}_idx

---

Pattern: index.ts (Domain Namespace)

// src/<module>/index.ts
import { eq, and, isNull, sql } from 'drizzle-orm';
import z from 'zod';

import { Database } from '../db/index.js';
import { Examples } from '../examples.js';
import { fn } from '../fn.js';
import { SomeTable, SomeEnum } from './<module>.sql.js';

export namespace SomeModule {
  // ── Info schema ─────────────────────────────────────────────────────
  // Single source of truth for the entity shape.
  // Every field typed here; .meta() adds OpenAPI metadata.
  // When a field changes here, TypeScript catches every usage.
  export const Info = z
    .object({
      id: z.string().meta({
        description: '…',
        example: Examples.SomeModule.id,
      }),
      // For enum fields, use z.enum(SomeEnum.enumValues) to stay in sync:
      provider: z.enum(SomeEnum.enumValues).meta({ … }),
      // Nullable + optional for JSON-blob / optional fields:
      metadata: z.record(z.string(), z.unknown()).nullable().optional().meta({ … }),
    })
    .meta({
      ref: 'SomeModule',
      description: '…',
      example: Examples.SomeModule,
    });

  export type Info = z.infer<typeof Info>;

  // ── create ───────────────────────────────────────────────────────────
  // Use Info.pick({…}) for the schema — keeps fields in sync with Info.
  // Input is the parsed object.
  // Use Database.use() for single-operation writes.
  export const create = fn(
    Info.pick({ id: true, name: true, email: true }),
    async (input) => {
      await Database.use(async (tx) => {
        await tx.insert(SomeTable).values({
          id: input.id,
          name: input.name,
          email: input.email ?? null,
        });
      });
      return input.id;
    }
  );

  // ── Single-field lookups ─────────────────────────────────────────────
  // Use Info.shape.<field> for the schema.
  // The callback receives the raw value, not { field: value }.
  export const fromID = fn(Info.shape.id, async (id) => {
    return Database.use(async (tx) => {
      return tx
        .select()
        .from(SomeTable)
        .where(and(eq(SomeTable.id, id), isNull(SomeTable.timeDeleted)))
        .then((rows) => rows.at(0) ?? null);
    });
  });

  export const fromSlug = fn(Info.shape.slug, async (slug) => {
    // …
  });

  // ── Multi-field lookups ──────────────────────────────────────────────
  // Use Info.pick({ field1: true, field2: true })
  export const findByProvider = fn(
    Info.pick({ provider: true, providerAccountId: true }),
    async (input) => {
      return Database.use(async (tx) => {
        return tx
          .select()
          .from(SomeTable)
          .where(and(
            eq(SomeTable.provider, input.provider),
            eq(SomeTable.providerAccountId, input.providerAccountId),
            isNull(SomeTable.timeDeleted),
          ))
          .then((rows) => rows.at(0) ?? null);
      });
    }
  );

  // ── List (no args) ───────────────────────────────────────────────────
  // Plain async function — no fn() wrapper since there's no input.
  export async function list() {
    return Database.use(async (tx) => {
      return tx
        .select()
        .from(SomeTable)
        .where(isNull(SomeTable.timeDeleted))
        .orderBy(SomeTable.timeCreated);
    });
  }

  // ── List by FK ───────────────────────────────────────────────────────
  export const listByUser = fn(Info.shape.userId, async (userId) => {
    return Database.use(async (tx) => {
      return tx
        .select()
        .from(SomeTable)
        .where(and(eq(SomeTable.userId, userId), isNull(SomeTable.timeDeleted)))
        .orderBy(SomeTable.timeCreated);
    });
  });

  // ── Update ───────────────────────────────────────────────────────────
  // If the update uses Info fields + possibly extra fields:
  export const updateSomething = fn(
    Info.pick({ id: true, otherField: true }).extend({
      extraField: z.string(),
    }),
    async (input) => {
      await Database.use(async (tx) => {
        await tx
          .update(SomeTable)
          .set({ otherField: input.otherField })
          .where(eq(SomeTable.id, input.id));
      });
    }
  );

  // ── Soft-delete ──────────────────────────────────────────────────────
  // Use sql\`now()\` for the timestamp (consistent with DB time).
  export const remove = fn(Info.shape.id, async (id) => {
    await Database.use(async (tx) => {
      await tx
        .update(SomeTable)
        .set({ timeDeleted: sql`now()` })
        .where(eq(SomeTable.id, id));
    });
  });

  // ── serialize ────────────────────────────────────────────────────────
  // Converts a DB row into the public API shape. Keeps serialization
  // decoupled from the DB layer.
  export function serialize(input: typeof SomeTable.$inferSelect): z.infer<typeof Info> {
    return {
      id: input.id,
      name: input.name,
      // Cast enums since drizzle returns a string at runtime:
      provider: input.provider as Info['provider'],
    };
  }

  // ── listByUserWithGames ──────────────────────────────────────────────
  // JOIN query with serialization inside the fn() boundary.
  // The .then() chain maps raw rows to the public shape immediately.
  export const listByUserWithGames = fn(Info.shape.userId, async (userId) => {
    return Database.use(async (tx) => {
      return tx
        .select({
          library: UserLibraryTable,
          game: GameTable
        })
        .from(UserLibraryTable)
        .leftJoin(GameTable, eq(UserLibraryTable.gameId, GameTable.id))
        .where(and(eq(UserLibraryTable.userId, userId), isNull(UserLibraryTable.timeDeleted)))
        .orderBy(UserLibraryTable.timeCreated)
        .then((rows) =>
          rows
            .filter((row) => row.game !== null)
            .map((row) => ({
              id: row.library.id,
              game: Game.serialize(row.game!),
              playtime2w: row.library.playtime2w,
              playtimeForever: row.library.playtimeForever,
              lastPlayed: row.library.lastPlayed?.toISOString() ?? null
            }))
        );
    });
  });
}

Key rules for fn() usage

Case	Schema	Callback receives
Single field	Info.shape.field	Raw value (string, boolean, etc.)
Multiple fields	Info.pick({a:true, b:true})	{ a, b } object
Full entity	Info	Full Info object
Info fields + extras	Info.pick({…}).extend({extra: z.type()})	{ …fields, extra }
No input	Regular async function	n/a

What fn() does

fn(schema, callback);
// → (input) => { schema.parse(input); return callback(parsed); }
// The returned function also has a .schema property for OpenAPI introspection.

---

Serialization Boundary Rule

All data transformation — including JOIN deserialization, field mapping, date stringification, and null filtering — happens INSIDE the fn() boundary, right after the DB query in a .then() chain. The API route is a dumb pass-through.

Why this matters

Approach	Queries	Boundary clarity
Bad: Raw rows from core, map/filter in route	N+1 (or raw)	Leaky — route knows DB schema
Bad: JOIN in core, but serialize in route	1	Still leaky — route owns shaping logic
Good: JOIN + serialize in .then() inside fn()	1	Clean — core returns JSON-safe objects

The pattern

// GOOD: serialization inside fn()
export const listByUserWithGames = fn(Info.shape.userId, async (userId) => {
  return Database.use(async (tx) => {
    return tx
      .select({ library: UserLibraryTable, game: GameTable })
      .from(UserLibraryTable)
      .leftJoin(GameTable, eq(UserLibraryTable.gameId, GameTable.id))
      .where(...)
      .orderBy(...)
      .then((rows) =>
        rows
          .filter((row) => row.game !== null)
          .map((row) => ({
            id: row.library.id,
            game: Game.serialize(row.game!),
            lastPlayed: row.library.lastPlayed?.toISOString() ?? null
          }))
      );
  });
});

// GOOD: API route is a thin pass-through
async (c) => {
  const data = await Library.listByUserWithGames(Actor.userID);
  return c.json({ data });
}

Rules

1. Never let raw Drizzle $inferSelect rows escape the core module. If a function returns joined data, it must be shaped before the return.
2. Use .then() after the query for map/filter/serialize. Keeps the async pipeline declarative and co-located with the SQL.
3. Re-use sibling serialize() functions for joined tables. e.g. Game.serialize(row.game!) when joining GameTable.
4. API routes only do: auth checks, input validation, calling the core fn, and c.json({ data }). No .map(), no .filter(), no field remapping.

---

Mutation Rule: Single-Query Reads via .returning()

Never execute a separate tx.select() or trigger a lookup function immediately after an insert or upsert mutation to fetch the updated state of a row.

Postgres natively supports the RETURNING clause. Always append .returning() directly to your mutation chains and destructure the resulting array (const [row] = await tx...). This ensures mutations remain atomic, avoids unnecessary connection pool overhead, and removes the latency penalty of running two sequential database operations.

---

Pattern: ID generation (src/id.ts)

Identifier.ascending('user')          // → "usr_<monotonic-id>"
Identifier.ascending('team')          // → "tem_<monotonic-id>"
Identifier.ascending('linkedAccount') // → "lac_<monotonic-id>"

// Prefixes are defined in Identifier.prefixes:
{
  user: 'usr',
  linkedAccount: 'lac',
  team: 'tem',
  teamMember: 'mem',
  verification: 'ver',
}

The IDs are 30-char strings: {prefix}_{26 base62 chars}. They are monotonically increasing (time-sortable) when using ascending().

---

Pattern: Examples (src/examples.ts)

export namespace Examples {
  export const Id = (prefix: keyof typeof Identifier.prefixes) =>
    `${Identifier.prefixes[prefix]}_${'X'.repeat(Identifier.LENGTH)}`;

  export const User = { id: Id('user'), name: '…', email: '…', … };
  export const LinkedAccount = { id: Id('linkedAccount'), provider: 'steam', … };
  export const Team = { id: Id('team'), slug: 'my-team', … };
  export const Member = { id: Id('teamMember'), role: 'owner' as const, … };
  export const Fingerprint = { id: Id('userFingerprint'), fingerprint: '…', … };
  export const GameDownload = { id: Id('gameDownload'), hostId: 'hst_…', gameId: Id('game'), status: 'downloading', … };
  export const Library = { id: Id('userLibrary'), playtimeForever: 150000, … };
  export const Depot = { id: Id('gameDepot'), depotId: 730, … };
}

Every entity in Examples must be added and imported by the Info schema's .meta({ example: … }).

---

Pattern: Environment (src/env.ts)

export namespace Env {
	export const Info = z.object({
		NODE_ENV: z.enum(['development', 'production', 'test']).default('development'),
		FRONTEND_URL: z.string().optional(),
		AUTH_ISSUER_URL: z.string().optional() // used by API auth middleware to verify tokens
	});
	export type Info = z.infer<typeof Info>;
	export const env: Info = Info.parse(process.env);
}

---

Pattern: OpenAuth Subjects (src/auth/subjects.ts)

import { createSubjects } from '@nestri/auth/subject';
import { z } from 'zod';

export const subjects = createSubjects({
	user: z.object({
		userID: z.string(),
		linkedAccountID: z.string()
	})
});

The JWT contains { type: 'user', properties: { userID, linkedAccountID } }. The API verifies via client.verify(subjects, token) from @nestri/auth/client.

---

Entity relationships

User ───1:N─── LinkedAccount    ← auth methods (Steam, Epic, etc.)
  │
  ├─── 1:N ─── Fingerprint     ← SSH public keys
  ├─── 1:N ─── Library         ← owned games with playtime
  │
  └─── N:M ─── Team            ← via Member
                                     └─ role: owner | admin | member

Game ───1:N─── Download        ← per-host game depot downloads

• User: Person record. Email is nullable (gaming accounts don't provide one).
• LinkedAccount: A gaming/OAuth identity. (provider, providerAccountId) is unique.
• Team: Organization for billing/collaboration. First team is auto-created as "personal" team.
• TeamMember: Joins User → Team with a role. (teamId, userId) is unique.

---

Database access

// Auto-scoped transaction (creates one if outside a transaction):
await Database.use(async (tx) => {
  await tx.insert(SomeTable).values({ … });
  const result = await tx.select().from(SomeTable).where(…);
});

// Explicit transaction:
await Database.transaction(async (tx) => {
  // All operations in one atomic transaction
});

// Side-effect queued after transaction commits:
Database.effect(() => sendEmail(…));

---

Soft-delete convention

Every table has time_deleted (nullable timestamp). Queries filter with isNull(table.timeDeleted). Deletion sets timeDeleted: sql\now()`` — never hard-deletes.

---

Dependency rule

• .sql.ts files may import from other .sql.ts files (for FK references).
• index.ts files may import from other index.ts files and .sql.ts files.
• Never import an index.ts from within a .sql.ts — that creates circular deps.

---

Actor Model (packages/core/src/actor.ts)

The Actor model identifies who/what is making a request. It uses AsyncLocalStorage (via Context.create()) so the actor is accessible anywhere in the call chain without passing it around.

Actor types

type ActorInfo =
	| { type: 'public'; properties: {} }
	| { type: 'user'; properties: { userID: string; linkedAccountID: string } }
	| {
			type: 'member';
			properties: { userID: string; teamID: string; role: 'owner' | 'admin' | 'member' };
	  }
	| { type: 'system'; properties: { teamID: string } }
	| { type: 'admin'; properties: {} };

API

Actor.use(); // → ActorInfo (throws if no context set)
Actor.with(value, fn); // Run fn in the given actor context
Actor.assert(type); // Assert current actor type, returns narrowed type
Actor.type; // → 'public' | 'user' | 'member' | 'system' | 'admin'
Actor.userID; // → string (user/member only)
Actor.linkedAccountID; // → string (user only)
Actor.useTeam; // → string (member/system only — the teamID)
Actor.role; // → 'owner' | 'admin' | 'member' (member only)
Actor.isSignedIn; // → boolean (true if not public)

When to pull from Actor vs pass as param

Functions that create resources owned by the current user (e.g. Team.create) pull userID from the actor context rather than requiring it as a parameter. This avoids passing ownerId/userId through the entire call chain.

Domain functions that need the actor's identity import Actor and call Actor.userID inside the fn() callback:

export const create = fn(Info.pick({ id: true, name: true, slug: true }), async (input) => {
	const ownerId = Actor.userID; // from AsyncLocalStorage
	// ...
});

Actor.userID inside Database.transaction()

When doing find-or-create logic that must scope to the authenticated user, pull Actor.userID inside the Database.transaction() callback. This keeps scoping co-located with the DB logic:

export const link = fn(
  z.object({ steamId: z.string(), profile: z.record(z.string(), z.unknown()).optional() }),
  async (input) => {
    return Database.transaction(async () => {
      const existing = await LinkedAccount.findByProvider({ ... });
      if (existing) return existing.id;
      const id = Identifier.ascending('linkedAccount');
      await LinkedAccount.create({ id, userId: Actor.userID, provider: 'steam', ... });
      return id;
    });
  }
);

This ensures the API endpoint is scoped to the user only — no userId param is passed from the route handler. The Actor.userID is set by the auth middleware's Actor.with(), propagated via AsyncLocalStorage.

Callers must wrap actor-dependent work in Actor.with() before calling these functions. The API middleware does this automatically for HTTP requests. The auth worker sets it up explicitly:

await Actor.with({ type: 'user', properties: { userID, linkedAccountID } }, async () => {
	await Team.createPersonal({ displayName: personaname });
});

---

Auth Flow

Auth Worker (apps/auth/src/index.ts)

A Cloudflare Worker using @nestri/auth (OpenAuth). Entry point is the success callback after OAuth:

1. Steam returns steamid → worker fetches profile from Steam API
2. Inside Database.transaction(): looks up existing LinkedAccount.findByProvider; if found returns existing user, else creates User + LinkedAccount
3. Wraps post-login setup in Actor.with(), then checks Member.listByUser(userID)
4. If no memberships, calls Team.createPersonal({ displayName })
5. Issues JWT via context.subject('user', { userID, linkedAccountID })

Auth Middleware (apps/api/app/middleware/auth.ts)

Hono middleware that runs on every API request:

1. Checks x-nestri-machine-id / x-nestri-machine-secret — a registered host authenticates as itself, and bad credentials fall through to public rather than erroring
2. Otherwise, reads Authorization: Bearer <token> header — a personal access token is resolved from the database, anything else is verified as a JWT
3. Verifies via client.verify(subjects, token) from @nestri/auth/client
4. If valid user subject:
   • Checks x-nestri-team header for team-scoped access
   • If team header present, verifies membership via Member.findByTeamAndUser
   • Sets actor to member (with role) or user type
5. If no token/invalid: sets actor to public type
6. Exports notPublic guard middleware — throws VisibleError('authentication', UNAUTHORIZED, …) if actor is public. Caught by onError → 401 JSON response. It admits machines too; what stops a host acting as its owner is Actor.userID, which refuses a machine outright.

OpenAuth Subjects (src/auth/subjects.ts)

export const subjects = createSubjects({
	user: z.object({ userID: z.string(), linkedAccountID: z.string() })
});

The JWT contains { type: 'user', properties: { userID, linkedAccountID } }. Env var AUTH_ISSUER_URL configures which issuer to trust for token verification.

---

Team Discriminator System

When creating a personal team (Team.createPersonal), the slug is derived from the display name:

// 1. Sanitize: lowercase, replace non-alphanumeric with dashes, trim edges, max 50 chars
const baseSlug = displayName.toLowerCase().replace(/[^a-z0-9]+/g, '-')...

// 2. Check if slug exists (fromSlug)
// 3. If taken, append random 4-digit discriminator: "name-1234"
const slug = existing ? `${baseSlug}-${discriminator}` : baseSlug;

This mirrors Discord's discriminator pattern. The discriminator is part of the slug string — not a separate column.

---

fn() and Actor Context

fn() itself is unchanged — it validates input against a zod schema and calls the callback. The actor context is available inside fn() callbacks because Actor.with() uses AsyncLocalStorage, which propagates automatically through await chains.

Every fn() callback can import and use Actor directly. No special wiring needed.

---

API Error Pattern (packages/core/src/error.ts)

Centralized error types used by both the domain layer and the API.

ErrorResponse

Zod schema for OpenAPI error responses:

import { z } from 'zod';

export const ErrorResponse = z
	.object({
		type: z.enum([
			'validation',
			'authentication',
			'forbidden',
			'not_found',
			'already_exists',
			'rate_limit',
			'internal'
		]),
		code: z.string(),
		message: z.string(),
		param: z.string().optional(),
		details: z.any().optional()
	})
	.meta({ ref: 'ErrorResponse' });

ErrorCodes

Structured error code constants:

Category	Codes
Validation	MISSING_REQUIRED_FIELD, ALREADY_EXISTS, TEAM_ALREADY_EXISTS, INVALID_PARAMETER, INVALID_FORMAT, INVALID_STATE, IN_USE
Authentication	UNAUTHORIZED, INVALID_TOKEN, EXPIRED_TOKEN, INVALID_CREDENTIALS
Permission	FORBIDDEN, INSUFFICIENT_PERMISSIONS, ACCOUNT_RESTRICTED
NotFound	RESOURCE_NOT_FOUND
RateLimit	TOO_MANY_REQUESTS, QUOTA_EXCEEDED
Server	INTERNAL_ERROR, SERVICE_UNAVAILABLE, DEPENDENCY_FAILURE

VisibleError

Throw this for any user-facing error. It carries structured data and converts cleanly to HTTP:

throw new VisibleError(
	'not_found',
	ErrorCodes.NotFound.RESOURCE_NOT_FOUND,
	`User ${id} does not exist`
);

• .statusCode() — maps type → HTTP status (validation→400, authentication→401, forbidden→403, not_found→404, already_exists→409, rate_limit→429, internal→500)
• .toResponse() → { type, code, message, param?, details? }

The API's global onError handler catches VisibleError + HTTPException + unknown errors, logging each and returning the correct JSON shape.

---