---
warning: DO NOT CHANGE THIS MANUALLY, THIS IS GENERATED BY https://github.com/duckdb/community-extensions repository, check README there
title: nats_rw
excerpt: |
  DuckDB Community Extensions
  Read and write NATS JetStream streams with SQL

extension:
  name: nats_rw
  description: Read and write NATS JetStream streams with SQL
  version: 0.1.0
  language: C++
  build: cmake
  license: BSL 1.1
  requires_toolchains: rust
  excluded_platforms: "osx_amd64;osx_arm64;wasm_mvp;wasm_eh;wasm_threads"
  maintainers:
    - robert-guangzhou
    - xiehuiqiang

repo:
  github: robert-guangzhou/duckdb-nats-rw
  ref: 34776855201e614ed4f94ab3a861c34285698569

docs:
  hello_world: |
    -- Write query results to a NATS JetStream stream
    COPY (SELECT 'hello' AS v) TO 'my_stream'
      (FORMAT nats_rw, url 'nats://localhost:4222', create_stream 'true');

    -- Read it back
    SELECT * FROM nats_rw_scan('my_stream', url := 'nats://localhost:4222');

    -- Extract JSON fields as columns
    SELECT device_id, location_zone
    FROM nats_rw_scan('my_stream', url := 'nats://localhost:4222',
        json_extract := ['device_id', 'location.zone']);

  extended_description: |
    The nats_rw extension provides bidirectional NATS JetStream access from DuckDB:

    - **Read**: `nats_rw_scan()` table function — bounded snapshot scan with
      subject filtering, sequence/time ranges, JSON field extraction, and
      predicate pushdown (WHERE seq/ts_nats automatically narrows the scan range)
    - **Write**: `COPY … TO '<stream>' (FORMAT nats_rw)` — publish query results
      with optional payload_column, subject_prefix, and auto stream creation
    - **Auth**: `CREATE SECRET (TYPE nats_rw, …)` — user/password, token, nkey,
      or credentials file, with scope-based auto-matching
    - **Metadata**: `nats_rw_streams()` and `nats_rw_stream_info()` for inspection
    - **Performance**: connection pooling (per-url cache) + predicate pushdown

    Connections are cached per (url, auth) for efficient repeated queries.

    Documentation: https://github.com/robert-guangzhou/duckdb-nats-rw

extension_star_count: 0
extension_star_count_pretty: 0
extension_download_count: null
extension_download_count_pretty: n/a
image: '/images/community_extensions/social_preview/preview_community_extension_nats_rw.png'
layout: community_extension_doc
---
### Compatibility Matrix

This table covers all DuckDB releases that have not reached [end-of-life](https://duckdb.org/release_calendar), including LTS releases, and shows the 2 most recent patch releases of each. Older patch releases are not listed, but the extension may be available for them as well.

<div class="extension_compatibility_table"></div>

| Platform | 1.4.4 | 1.4.5 | 1.5.5 | 1.5.6 | 2.0.0 |
| :--- | :---: | :---: | :---: | :---: | :---: |
| Linux AMD64 | ❌ | ❌ | ❌ | ❌ | ✅ |
| Linux ARM64 | ❌ | ❌ | ❌ | ❌ | ✅ |
| macOS AMD64 | ❌ | ❌ | ❌ | ❌ | ❌ |
| macOS ARM64 | ❌ | ❌ | ❌ | ❌ | ❌ |
| Windows AMD64 | ❌ | ❌ | ❌ | ❌ | ✅ |
| Windows ARM64 | ❌ | ❌ | ❌ | ❌ | ❌ |
| WebAssembly | ❌ | ❌ | ❌ | ❌ | ❌ |

### Installing and Loading
```sql
INSTALL {{ page.extension.name }} FROM community;
LOAD {{ page.extension.name }};
```

{% if page.docs.hello_world %}
### Example
```sql
{{ page.docs.hello_world }}```
{% endif %}

{% if page.docs.extended_description %}
### About {{ page.extension.name }}
{{ page.docs.extended_description }}
{% endif %}
### Added Functions

<div class="extension_functions_table"></div>

|    function_name    | function_type | description | comment | examples |
|---------------------|---------------|-------------|---------|----------|
| nats_rw_scan        | table         | NULL        | NULL    |          |
| nats_rw_stream_info | table         | NULL        | NULL    |          |
| nats_rw_streams     | table         | NULL        | NULL    |          |
| nats_rw_version     | scalar        | NULL        | NULL    |          |

### Overloaded Functions

<div class="extension_functions_table"></div>

This extension does not add any function overloads.

### Added Types

<div class="extension_types_table"></div>

This extension does not add any types.

### Added Settings

<div class="extension_settings_table"></div>

|      name      |                       description                       | input_type | scope  | aliases | typed_value |
|----------------|---------------------------------------------------------|------------|--------|---------|-------------|
| temp_directory | Set the directory to which temporary files are written. | VARCHAR    | GLOBAL | []      | post.db.tmp |