docs: document duckdb support

docs-site/content/docs/cli-reference/ktx-connection.mdx

@@ -70,6 +70,9 @@ Native database connections report `Status: ok` when the connector probe
 passes. Source connectors report connector-specific details such as Metabase
 database count, Looker user, Notion bot, or Git repo URL.
 
+DuckDB connection tests open the configured file read-only. Missing files are
+reported as `File not found: <path>` and are not created.
+
 ```text
 Connection test passed: my-warehouse
 Driver: postgres

docs-site/content/docs/cli-reference/ktx-setup.mdx

@@ -100,10 +100,10 @@ runtime features are missing.
 
 | Flag | Description |
 |------|-------------|
-| `--database <driver>` | Database driver to configure; repeatable. Choices: `sqlite`, `postgres`, `mysql`, `clickhouse`, `sqlserver`, `bigquery`, `snowflake` |
+| `--database <driver>` | Database driver to configure; repeatable. Choices: `sqlite`, `duckdb`, `postgres`, `mysql`, `clickhouse`, `sqlserver`, `bigquery`, `snowflake` |
 | `--database-connection-id <id>` | Existing selected connection id; repeatable |
 | `--new-database-connection-id <id>` | Connection id for one new database connection |
-| `--database-url <url>` | URL, `env:NAME`, or `file:/path` for one new URL-style database connection; also used as the SQLite path |
+| `--database-url <url>` | URL, `env:NAME`, or `file:/path` for one new URL-style database connection; also used as the SQLite or DuckDB path |
 | `--database-schema <schema>` | Database schema or dataset to include; repeatable |
 | `--skip-databases` | Leave database setup incomplete |
 
@@ -111,6 +111,10 @@ KTX needs at least one database connection before it can build database
 context. Use `--skip-databases` only when intentionally leaving the project
 incomplete.
 
+```bash
+ktx setup --new --database duckdb --new-database-connection-id warehouse --database-url ./data/warehouse.duckdb
+```
+
 ### Query History
 
 | Flag | Description |

docs-site/content/docs/cli-reference/ktx-sql.mdx

@@ -35,6 +35,9 @@ Quote SQL in shell scripts and when the query contains spaces or punctuation.
 # Count rows in a table
 ktx sql --connection warehouse "select count(*) from public.orders"
 
+# Count rows in a DuckDB table
+ktx sql --connection warehouse "select count(*) as rows from orders"
+
 # Return a small result set
 ktx sql \
   --connection warehouse \

docs-site/content/docs/community/contributing.mdx

@@ -92,6 +92,7 @@ packages/
   connector-snowflake/  # Snowflake connector
   connector-bigquery/   # BigQuery connector
   connector-clickhouse/ # ClickHouse connector
+  connector-duckdb/     # DuckDB connector
   connector-mysql/      # MySQL connector
   connector-sqlserver/  # SQL Server connector
   connector-sqlite/     # SQLite connector

docs-site/content/docs/integrations/primary-sources.mdx

@@ -1,6 +1,6 @@
 ---
 title: Primary Sources
-description: Connect KTX to PostgreSQL, Snowflake, BigQuery, ClickHouse, MySQL, SQL Server, or SQLite.
+description: Connect KTX to PostgreSQL, Snowflake, BigQuery, ClickHouse, MySQL, SQL Server, DuckDB, or SQLite.
 ---
 
 KTX connects to your data warehouse or database to build schema context,
@@ -21,12 +21,12 @@ Agents should prefer environment or file references over literal secrets.
 
 | Field | Required | Applies to | Description |
 |-------|----------|------------|-------------|
-| `driver` | Yes | all connections | Connector driver such as `postgres`, `snowflake`, `bigquery`, `clickhouse`, `mysql`, `sqlserver`, or `sqlite` |
+| `driver` | Yes | all connections | Connector driver such as `postgres`, `snowflake`, `bigquery`, `clickhouse`, `mysql`, `sqlserver`, `duckdb`, or `sqlite` |
 | `url` | One of the connection methods | URL-style connectors | Database URL, `env:NAME`, or `file:/path/to/secret` |
 | `host`, `port`, `database`, `username`, `password` | One of the connection methods | PostgreSQL, MySQL, ClickHouse, SQL Server | Field-by-field connection values |
 | `schema` or `schemas` | No | schema-aware warehouses | Single schema or list of schemas to scan |
 | `context.queryHistory` | No | PostgreSQL, Snowflake, BigQuery | Enables query-history ingestion when the warehouse supports it |
-| `path` | Yes for path-style SQLite | SQLite | Local SQLite database path or `env:NAME` reference |
+| `path` | Yes for path-style SQLite and DuckDB | SQLite, DuckDB | Local database path or `env:NAME` reference |
 | `max_bytes_billed` | No | BigQuery | Maximum bytes billed per query job |
 | `job_timeout_ms` | No | BigQuery | BigQuery query job timeout in milliseconds |
 | `project_id` | No | BigQuery | Optional local descriptor and mapping metadata; not used for BigQuery authentication |
@@ -502,6 +502,36 @@ No authentication required - SQLite is file-based. The file must be readable by
 - Foreign key enforcement requires explicit `PRAGMA foreign_keys = ON`
 - Database file must exist before `ktx connection test` or ingest runs
 
+## DuckDB
+
+File-backed local connector using `@duckdb/node-api`. DuckDB support is
+local-file only in v1.
+
+### Connection config
+
+```yaml title="ktx.yaml"
+connections:
+  warehouse:
+    driver: duckdb
+    path: data/warehouse.duckdb
+```
+
+KTX opens the configured file read-only and fails if the file is missing,
+points to a directory, or uses `:memory:`.
+
+### Features
+
+| Feature | Supported | Notes |
+|---------|-----------|-------|
+| Tables & views | Yes | Via `information_schema.tables` |
+| Primary keys | Yes | Via `duckdb_constraints()` |
+| Foreign keys | Yes | Via `duckdb_constraints()` |
+| Row count estimates | Yes | Exact count via `SELECT COUNT(*)` |
+| Column statistics | No | - |
+| Query history | No | - |
+| Table sampling | Yes | - |
+| Nested analysis | No | - |
+
 ## Common errors
 
 | Error or symptom | Likely cause | Recovery |