diff --git a/go.mod b/go.mod
index b2d5d014..e2be7856 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,5 @@
 module fn-registry
 
 go 1.22.2
+
+require github.com/mattn/go-sqlite3 v1.14.37
diff --git a/go.sum b/go.sum
new file mode 100644
index 00000000..9c79a75d
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/mattn/go-sqlite3 v1.14.37 h1:3DOZp4cXis1cUIpCfXLtmlGolNLp2VEqhiB/PARNBIg=
+github.com/mattn/go-sqlite3 v1.14.37/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
diff --git a/registry/db.go b/registry/db.go
new file mode 100644
index 00000000..f184864f
--- /dev/null
+++ b/registry/db.go
@@ -0,0 +1,153 @@
+package registry
+
+import (
+	"database/sql"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+const schemaSQL = `
+CREATE TABLE IF NOT EXISTS functions (
+	id               TEXT PRIMARY KEY,
+	name             TEXT NOT NULL,
+	kind             TEXT NOT NULL CHECK(kind IN ('function','pipeline','component')),
+	lang             TEXT NOT NULL,
+	domain           TEXT NOT NULL,
+	version          TEXT NOT NULL DEFAULT '1.0.0',
+	purity           TEXT NOT NULL CHECK(purity IN ('pure','impure')),
+	signature        TEXT NOT NULL DEFAULT '',
+	description      TEXT NOT NULL,
+	tags             TEXT NOT NULL DEFAULT '[]',
+	uses_functions   TEXT NOT NULL DEFAULT '[]',
+	uses_types       TEXT NOT NULL DEFAULT '[]',
+	returns          TEXT NOT NULL DEFAULT '[]',
+	returns_optional INTEGER NOT NULL DEFAULT 0,
+	error_type       TEXT NOT NULL DEFAULT '',
+	imports          TEXT NOT NULL DEFAULT '[]',
+	example          TEXT NOT NULL DEFAULT '',
+	tested           INTEGER NOT NULL DEFAULT 0,
+	tests            TEXT NOT NULL DEFAULT '[]',
+	test_file_path   TEXT NOT NULL DEFAULT '',
+	file_path        TEXT NOT NULL DEFAULT '',
+	created_at       TEXT NOT NULL,
+	updated_at       TEXT NOT NULL,
+	-- Component fields
+	props            TEXT NOT NULL DEFAULT '[]',
+	emits            TEXT NOT NULL DEFAULT '[]',
+	has_state        INTEGER,
+	framework        TEXT NOT NULL DEFAULT '',
+	variant          TEXT NOT NULL DEFAULT '[]'
+);
+
+CREATE TABLE IF NOT EXISTS types (
+	id          TEXT PRIMARY KEY,
+	name        TEXT NOT NULL,
+	lang        TEXT NOT NULL,
+	domain      TEXT NOT NULL,
+	version     TEXT NOT NULL DEFAULT '1.0.0',
+	algebraic   TEXT NOT NULL CHECK(algebraic IN ('product','sum')),
+	definition  TEXT NOT NULL DEFAULT '',
+	description TEXT NOT NULL,
+	tags        TEXT NOT NULL DEFAULT '[]',
+	uses_types  TEXT NOT NULL DEFAULT '[]',
+	file_path   TEXT NOT NULL DEFAULT '',
+	created_at  TEXT NOT NULL,
+	updated_at  TEXT NOT NULL
+);
+
+CREATE VIRTUAL TABLE IF NOT EXISTS functions_fts USING fts5(
+	id,
+	name,
+	description,
+	tags,
+	signature,
+	domain,
+	content='functions',
+	content_rowid='rowid'
+);
+
+CREATE VIRTUAL TABLE IF NOT EXISTS types_fts USING fts5(
+	id,
+	name,
+	description,
+	tags,
+	domain,
+	content='types',
+	content_rowid='rowid'
+);
+
+-- Triggers to keep FTS in sync
+CREATE TRIGGER IF NOT EXISTS functions_ai AFTER INSERT ON functions BEGIN
+	INSERT INTO functions_fts(rowid, id, name, description, tags, signature, domain)
+	VALUES (new.rowid, new.id, new.name, new.description, new.tags, new.signature, new.domain);
+END;
+
+CREATE TRIGGER IF NOT EXISTS functions_ad AFTER DELETE ON functions BEGIN
+	INSERT INTO functions_fts(functions_fts, rowid, id, name, description, tags, signature, domain)
+	VALUES ('delete', old.rowid, old.id, old.name, old.description, old.tags, old.signature, old.domain);
+END;
+
+CREATE TRIGGER IF NOT EXISTS functions_au AFTER UPDATE ON functions BEGIN
+	INSERT INTO functions_fts(functions_fts, rowid, id, name, description, tags, signature, domain)
+	VALUES ('delete', old.rowid, old.id, old.name, old.description, old.tags, old.signature, old.domain);
+	INSERT INTO functions_fts(rowid, id, name, description, tags, signature, domain)
+	VALUES (new.rowid, new.id, new.name, new.description, new.tags, new.signature, new.domain);
+END;
+
+CREATE TRIGGER IF NOT EXISTS types_ai AFTER INSERT ON types BEGIN
+	INSERT INTO types_fts(rowid, id, name, description, tags, domain)
+	VALUES (new.rowid, new.id, new.name, new.description, new.tags, new.domain);
+END;
+
+CREATE TRIGGER IF NOT EXISTS types_ad AFTER DELETE ON types BEGIN
+	INSERT INTO types_fts(types_fts, rowid, id, name, description, tags, domain)
+	VALUES ('delete', old.rowid, old.id, old.name, old.description, old.tags, old.domain);
+END;
+
+CREATE TRIGGER IF NOT EXISTS types_au AFTER UPDATE ON types BEGIN
+	INSERT INTO types_fts(types_fts, rowid, id, name, description, tags, domain)
+	VALUES ('delete', old.rowid, old.id, old.name, old.description, old.tags, old.domain);
+	INSERT INTO types_fts(rowid, id, name, description, tags, domain)
+	VALUES (new.rowid, new.id, new.name, new.description, new.tags, new.domain);
+END;
+`
+
+// DB wraps a SQLite connection for the registry.
+type DB struct {
+	conn *sql.DB
+	path string
+}
+
+// Open opens or creates the registry database at the given path.
+func Open(path string) (*DB, error) {
+	dir := filepath.Dir(path)
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return nil, fmt.Errorf("creating db directory: %w", err)
+	}
+
+	conn, err := sql.Open("sqlite3", path+"?_journal_mode=WAL&_foreign_keys=on")
+	if err != nil {
+		return nil, fmt.Errorf("opening database: %w", err)
+	}
+
+	if _, err := conn.Exec(schemaSQL); err != nil {
+		conn.Close()
+		return nil, fmt.Errorf("applying schema: %w", err)
+	}
+
+	return &DB{conn: conn, path: path}, nil
+}
+
+// Close closes the database connection.
+func (db *DB) Close() error {
+	return db.conn.Close()
+}
+
+// Drop removes the database file. Used by `fn index` to regenerate.
+func (db *DB) Drop() error {
+	db.Close()
+	return os.Remove(db.path)
+}