diff --git a/packages/core/package.json b/packages/core/package.json
index 594dd16..780e887 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -14,6 +14,7 @@
     "./providers/codex": "./dist/providers/codex.js",
     "./providers/types": "./dist/providers/types.js",
     "./query": "./dist/query.js",
+    "./sqlite-types": "./dist/sqlite-types.js",
     "./tx": "./dist/tx.js",
     "./write-coordinator": "./dist/write-coordinator.js",
     "./writer-lease": "./dist/writer-lease.js"
diff --git a/packages/core/src/db.ts b/packages/core/src/db.ts
index 9247fa8..5f6ad25 100644
--- a/packages/core/src/db.ts
+++ b/packages/core/src/db.ts
@@ -2,14 +2,13 @@
 import { createRequire } from 'node:module';
 import { CLAUDE_DIR, CODEX_DIR, TEXT_LIMIT, trunc, truncJson, extractText, extractContentType, extractMessageIsMeta, filePath, isDir, readLines } from './parsing.ts';
 import { configureConnection } from './tx.ts';
+import type { NodeSqliteDb, SqliteDb } from './sqlite-types.ts';
 const require = createRequire(import.meta.url);
 const fs = require('node:fs');
 const path = require('node:path');
 const os = require('node:os');
 const { DatabaseSync } = require('node:sqlite');
 
-type SqliteDb = any;
-
 const OBELISK_DIR = path.join(os.homedir(), '.obelisk');
 const LEGACY_DB_PATH = path.join(CLAUDE_DIR, 'obelisk.sqlite');
 const DB_PATH = path.join(OBELISK_DIR, 'obelisk.sqlite');
@@ -22,7 +21,7 @@ function migrateLegacyDbIfNeeded() {
   fs.copyFileSync(LEGACY_DB_PATH, DB_PATH);
 }
 
-function openDb() {
+function openDb(): NodeSqliteDb {
   migrateLegacyDbIfNeeded();
   fs.mkdirSync(path.dirname(DB_PATH), { recursive: true });
   const db = new DatabaseSync(DB_PATH);
@@ -35,18 +34,18 @@ function openDb() {
 
 // Queries and daemon-arbitration checks must never migrate/configure the index.
 // The caller is responsible for ensuring the database exists first.
-function openReadDb() {
+function openReadDb(): NodeSqliteDb {
   const db = new DatabaseSync(DB_PATH, { readOnly: true });
   db.exec('PRAGMA busy_timeout=250');
   return db;
 }
 
-function openWriterLeaseDb(lockPath: string): SqliteDb {
+function openWriterLeaseDb(lockPath: string): NodeSqliteDb {
   return new DatabaseSync(lockPath);
 }
 
 function ensureColumn(db: SqliteDb, table: string, column: string, definition: string): void {
-  const columns = db.prepare(`PRAGMA table_info(${table})`).all().map((c: { name: string }) => c.name);
+  const columns = db.prepare(`PRAGMA table_info(${table})`).all().map(c => c.name);
   if (!columns.includes(column)) db.exec(`ALTER TABLE ${table} ADD COLUMN ${column} ${definition}`);
 }
 
diff --git a/packages/core/src/indexer.ts b/packages/core/src/indexer.ts
index 0a0d186..043e5de 100644
--- a/packages/core/src/indexer.ts
+++ b/packages/core/src/indexer.ts
@@ -11,21 +11,13 @@ import { runRetryableWriteTransaction, isBeginBusyFailure, hasUnusableTransactio
 import { parse as claudeParse } from './providers/claude.ts';
 import { parse as codexParse } from './providers/codex.ts';
 import type { Cursor, IndexRecord } from './providers/types.ts';
+import type { ClaudeJsonlFile } from './parsing.ts';
+import type { NodeSqliteDb, SqliteRow } from './sqlite-types.ts';
 
 const HISTORY_PATH = path.join(CLAUDE_DIR, 'history.jsonl');
 
-type SqliteDb = any;
 type JsonRecord = Record<string, any>;
 
-interface ClaudeFileInfo {
-  path: string;
-  sessionId: string;
-  project: string;
-  isSubagent: boolean;
-  agentId?: string;
-  workflowRunId?: string;
-}
-
 interface SkippedFile {
   path: string;
   error: string;
@@ -42,7 +34,7 @@ function errorMessage(error: unknown): string {
 }
 
 
-function needsReindex(db: SqliteDb, fp: string) {
+function needsReindex(db: NodeSqliteDb, fp: string) {
   const mt = fs.statSync(fp).mtimeMs;
   const row = db.prepare('SELECT mtime, lines_processed FROM index_state WHERE jsonl_path = ?').get(fp);
   if (!row) return { needed: true, skip: 0 };
@@ -50,7 +42,7 @@ function needsReindex(db: SqliteDb, fp: string) {
 }
 
 
-function indexCodexSessionIndex(db: SqliteDb): void {
+function indexCodexSessionIndex(db: NodeSqliteDb): void {
   const indexPath = path.join(CODEX_DIR, 'session_index.jsonl');
   if (!fs.existsSync(indexPath)) return;
   readLines(indexPath, (line) => {
@@ -67,7 +59,7 @@ function indexCodexSessionIndex(db: SqliteDb): void {
   });
 }
 
-function refreshSessionProjectPaths(db: SqliteDb): void {
+function refreshSessionProjectPaths(db: NodeSqliteDb): void {
   const sessions = db.prepare('SELECT id, project FROM sessions').all();
   const cwdStmt = db.prepare(`
     SELECT cwd
@@ -77,13 +69,13 @@ function refreshSessionProjectPaths(db: SqliteDb): void {
   `);
   const update = db.prepare('UPDATE sessions SET project_path = ? WHERE id = ?');
   for (const session of sessions) {
-    const cwds = cwdStmt.all(session.id).map((row: JsonRecord) => row.cwd);
+    const cwds = cwdStmt.all(session.id).map((row: SqliteRow) => row.cwd);
     const projectPath = inferProjectPath(session.project, cwds);
     if (projectPath) update.run(projectPath, session.id);
   }
 }
 
-function indexSubagentMeta(db: SqliteDb, fi: ClaudeFileInfo): void {
+function indexSubagentMeta(db: NodeSqliteDb, fi: ClaudeJsonlFile): void {
   if (!fi.isSubagent) return;
   const mp = fi.path.replace('.jsonl', '.meta.json');
   if (!fs.existsSync(mp)) return;
@@ -104,7 +96,7 @@ function indexSubagentMeta(db: SqliteDb, fi: ClaudeFileInfo): void {
   }
 }
 
-function indexWorkflows(db: SqliteDb): void {
+function indexWorkflows(db: NodeSqliteDb): void {
   if (!fs.existsSync(PROJECTS_DIR)) return;
   let projects;
   try { projects = fs.readdirSync(PROJECTS_DIR); } catch { return; }
@@ -145,7 +137,7 @@ function indexWorkflows(db: SqliteDb): void {
   }
 }
 
-function indexHistory(db: SqliteDb): void {
+function indexHistory(db: NodeSqliteDb): void {
   if (!fs.existsSync(HISTORY_PATH)) return;
   readLines(HISTORY_PATH, (line) => {
     let item: JsonRecord;
@@ -162,7 +154,7 @@ function indexHistory(db: SqliteDb): void {
 const BUILD_DEBOUNCE_MS = 30000;
 const APP_HEARTBEAT_FRESH_MS = 60000;
 
-function shouldSkipBuild(db: SqliteDb, { now = Date.now(), ignoreRecentBuild = false }: BuildCheckOptions = {}) {
+function shouldSkipBuild(db: NodeSqliteDb, { now = Date.now(), ignoreRecentBuild = false }: BuildCheckOptions = {}) {
   const appHeartbeat = db.prepare("SELECT mtime FROM index_state WHERE jsonl_path='__app_heartbeat__'").get();
   if (appHeartbeat && now - appHeartbeat.mtime < APP_HEARTBEAT_FRESH_MS) {
     return { skip: true, reason: 'daemon_active' };
diff --git a/packages/core/src/parsing.ts b/packages/core/src/parsing.ts
index 8ad4502..6816d8c 100644
--- a/packages/core/src/parsing.ts
+++ b/packages/core/src/parsing.ts
@@ -17,7 +17,7 @@ const TEXT_LIMIT = 10000;
 type JsonRecord = Record<string, any>;
 type JsonValue = any;
 
-interface ClaudeJsonlFile {
+export interface ClaudeJsonlFile {
   path: string;
   sessionId: string;
   project: string;
@@ -27,7 +27,7 @@ interface ClaudeJsonlFile {
   source?: 'claude';
 }
 
-interface CodexJsonlFile {
+export interface CodexJsonlFile {
   path: string;
   source: 'codex';
 }
diff --git a/packages/core/src/providers/types.ts b/packages/core/src/providers/types.ts
index 829bc78..e72587f 100644
--- a/packages/core/src/providers/types.ts
+++ b/packages/core/src/providers/types.ts
@@ -10,7 +10,7 @@
 //     that consumes the records and writes them (index_state, FTS, upsert).
 //
 // This file defines only the shapes crossing that boundary. Record fields mirror
-// the columns in scripts/schema.sql; keep them in sync. Types only — no runtime
+// the columns in packages/core/src/schema.sql; keep them in sync. Types only — no runtime
 // code — so consumers must import with `import type`.
 
 // Opaque per-unit resume/watermark token. The orchestration stores it verbatim
@@ -47,7 +47,7 @@ export interface DiscoverContext {
 }
 
 /** Discriminated union of everything an adapter's parse can emit. Each record
- * kind maps to one schema table (see scripts/schema.sql); `delete-session` is
+ * kind maps to one schema table (see packages/core/src/schema.sql); `delete-session` is
  * the exception — a retraction op, not a table. Sources without a table
  * (history.jsonl, codex session_index.jsonl) are not records: adapters fold them
  * into the SessionRecord they already emit. */
diff --git a/packages/core/src/query.ts b/packages/core/src/query.ts
index 05bbdc4..1b905b8 100644
--- a/packages/core/src/query.ts
+++ b/packages/core/src/query.ts
@@ -1,8 +1,8 @@
 // Query and attune sandbox helpers for the Core package.
 import { readLines, fs, path } from './db.ts';
+import type { SqliteDb, SqliteRow } from './sqlite-types.ts';
 
-type SqliteDb = any;
-type DbRow = Record<string, any>;
+type DbRow = SqliteRow;
 
 interface QueryOptions extends Record<string, any> {
   limit?: number;
@@ -162,7 +162,7 @@ function createQueryApi(db: SqliteDb) {
     if (!msg) return null;
     const session = db.prepare('SELECT * FROM sessions WHERE id=?').get(msg.session_id);
     const chain: DbRow[] = [];
-    let cur = msg;
+    let cur: DbRow | undefined = msg;
     while (cur?.parent_uuid) { cur = db.prepare('SELECT * FROM messages WHERE uuid=?').get(cur.parent_uuid); if (cur) chain.unshift(cur); }
     const subagent = msg.agent_id ? db.prepare('SELECT * FROM subagents WHERE agent_id=?').get(msg.agent_id) : null;
     let workflow = null;
@@ -176,7 +176,7 @@ function createQueryApi(db: SqliteDb) {
   const trace = (uuid: string) => {
     const chain: DbRow[] = [];
     let cur = db.prepare('SELECT * FROM messages WHERE uuid=?').get(uuid);
-    while (cur) { chain.unshift(cur); cur = cur.parent_uuid ? db.prepare('SELECT * FROM messages WHERE uuid=?').get(cur.parent_uuid) : null; }
+    while (cur) { chain.unshift(cur); cur = cur.parent_uuid ? db.prepare('SELECT * FROM messages WHERE uuid=?').get(cur.parent_uuid) : undefined; }
     return chain;
   };
 
diff --git a/packages/core/src/sqlite-types.ts b/packages/core/src/sqlite-types.ts
new file mode 100644
index 0000000..4e0f4ef
--- /dev/null
+++ b/packages/core/src/sqlite-types.ts
@@ -0,0 +1,21 @@
+// Minimal structural types shared by node:sqlite and better-sqlite3 consumers.
+// SQLite rows and bindings are dynamic at this boundary; domain records become
+// strongly typed after parsing, in providers/types.ts.
+
+export type SqliteRow = Record<string, any>;
+
+export interface SqliteStatement {
+  all(...bindings: any[]): SqliteRow[];
+  get(...bindings: any[]): SqliteRow | undefined;
+  run(...bindings: any[]): unknown;
+}
+
+export interface SqliteDb {
+  exec(sql: string): unknown;
+  prepare(sql: string): SqliteStatement;
+  close(): void;
+}
+
+export interface NodeSqliteDb extends SqliteDb {
+  readonly isTransaction: boolean;
+}
diff --git a/tests/build-skill.test.mjs b/tests/build-skill.test.mjs
index f6e0f81..cdf4a17 100644
--- a/tests/build-skill.test.mjs
+++ b/tests/build-skill.test.mjs
@@ -32,7 +32,8 @@ test('build:skill produces a runnable, readable, .ts-free skill artifact', () =>
     'package.json', 'SKILL.md', 'references/api-reference.md',
     'scripts/core.js', 'scripts/persist.js', 'scripts/providers/claude.js',
     'scripts/providers/codex.js', 'scripts/runtime.js', 'scripts/indexer.js',
-    'scripts/db.js', 'scripts/parsing.js', 'scripts/query.js', 'scripts/schema.sql',
+    'scripts/db.js', 'scripts/parsing.js', 'scripts/query.js',
+    'scripts/sqlite-types.js', 'scripts/schema.sql',
   ]) {
     assert.ok(existsSync(join(skillDir, rel)), `artifact missing ${rel}`);
   }