WIP Disclaimer

This template is currently work-in-progress. Feel free to play around with it and give us feedback. Note also that this template depends on a development version of DuckDB. Follow https://duckdb.org/news for more information on official launch.

DuckDB Extension Template

The main goal of this template is to allow users to easily develop, test and distribute their own DuckDB extension.

Build

To build the extension:

make

The main binaries that will be built are:

./build/release/duckdb/duckdb
./build/release/duckdb/test/unittest
./build/release/duckdb/extension/<extension_name>/<extension_name>.duckdb_extension

• duckdb is the binary for the duckdb shell with the extension code automatically loaded.
• unittest is the test runner of duckdb. Again, the extension is already linked into the binary.
• <extension_name>.duckdb_extension is the loadable binary as it would be distributed.

Running the extension

To run the extension code, simply start the shell with ./build/release/duckdb.

Now we can use the features from the extension directly in DuckDB. The template contains a single scalar function do_a_boilerplate that takes no arguments and returns a string:

D select do_a_boilerplate() as result;
┌────────────────────┐
│       result       │
│      varchar       │
├────────────────────┤
│ I'm a boilerplate! │
└────────────────────┘

Running the tests

Different tests can be created for DuckDB extensions. The primary way of testing DuckDB extensions should be the SQL tests in ./test/sql. These SQL tests can be run using:

make test

Getting started with your own extension

After creating a repository from this template, the first step is to name your extension. To rename the extension, run:

./scripts/set_extension_name.sh <extension_name_you_want>

Feel free to delete the script after this step.

Now you're good to go! After a (re)build, you should now be able to use your duckdb extension:

./build/release/duckdb/duckdb
D select do_a_<extension_name_you_chose>() as result;
┌───────────────────────────────────┐
│                result             │
│               varchar             │
├───────────────────────────────────┤
│ I'm a <extension_name_you_chose>! │
└───────────────────────────────────┘

For inspiration/examples on how to extend DuckDB in a more meaningful way, check out the in-tree extensions in https://github.com/duckdb/duckdb and the out-of-tree extensions in https://github.com/duckdblabs!

Distributing your extension

Easy distribution of extensions built with this template is facilitated using a similar process used by DuckDB itself. Binaries are generated for various versions/platforms allowing duckdb to automatically install the correct binary.

This step requires that you pass the following 4 parameters to your github repo as action secrets:

secret name	description
S3_REGION	s3 region holding your bucket
S3_BUCKET	the name of the bucket to deploy to
S3_DEPLOY_ID	the S3 key id
S3_DEPLOY_KEY	the S3 key secret

After setting these variables, all pushes to master will trigger a new (dev) release.