Community extensions

Registering the extension in duckdb/community-extensions is what turns "download a file from a GitHub Release" into:

INSTALL duckfn_quantstats FROM community;   -- once, needs network
LOAD duckfn_quantstats;

The community build is signed and matches the user's DuckDB version, so -unsigned is no longer needed. The registration itself is a pull request that adds two files:

In this repository	In the community repository
community-extension/description.yml	extensions/duckfn_quantstats/description.yml
community-extension/docs/function_descriptions.csv	extensions/duckfn_quantstats/docs/function_descriptions.csv

The directory name must equal extension.name exactly — the community repository's scripts/build.py checks it.

Once registered, the download becomes one statement:

The CSV

The Added Functions table on the community extension page gets a function's description, comment and example from this CSV and nowhere else: DuckDB's C extension API has no way to set them. The text comes from the description / comment / example arguments of the #[duck_*] attributes, so it lives next to the function it describes:

#[duck_aggregate_function(
    description = "Renders one quantstats HTML report per symbol from a long table of periodic returns",
    comment = "…",
    examples = ["SELECT unnest(qs_html_reports(…)) FROM daily_returns", "…"]
)]

Regenerate and copy it whenever those attributes change:

just docs_csv
cp target/function_descriptions.csv community-extension/docs/function_descriptions.csv

Several examples are joined with "; " on export and lose their trailing semicolons; newlines collapse into spaces, because the target is a Markdown table. Write one complete statement per entry, in English. See Function descriptions for the full story.

description.yml

The file is copied to the community repository as it is, so it holds fields and no comments. The fields that need a decision:

Field	What to put there
extension.name	duckfn_quantstats, identical to the directory name and to the entry-point symbol.
extension.description	One line, shown in the extension list.
extension.version	The released version, without a -dev.N suffix.
extension.language / build	Rust and cargo.
extension.license	MIT (the repository's LICENSE). Note the community docs page spells it licence; the real schema is license.
extension.requires_toolchains	"rust;python3" — the same value the CI workflow passes as extra_toolchains.
extension.maintainers	Your GitHub handle.
repo.github	shijianjs/duckfn-quantstats.
repo.ref	The commit SHA (40 characters) of the released version — git rev-list -n 1 v0.1.0 — not main and not the tag name. A registration points at immutable code, and a build from a branch would claim a development version.
docs.hello_world	A runnable example, rendered into a code block. Do not write INSTALL / LOAD here: the page adds those itself.
docs.extended_description	The prose around the function table.

community-extension/AGENTS.md explains each field's provenance and the submission steps in more detail.

Submitting

# 1. in a clone of your fork of duckdb/community-extensions
git checkout -b add-duckfn-quantstats

# 2. copy the two files into place
mkdir -p extensions/duckfn_quantstats/docs
cp <this repo>/community-extension/description.yml extensions/duckfn_quantstats/
cp <this repo>/community-extension/docs/function_descriptions.csv extensions/duckfn_quantstats/docs/

# 3. commit, push, open the PR
git add extensions/duckfn_quantstats
git commit -m "Add duckfn_quantstats: …"
gh pr create --repo duckdb/community-extensions --base main --head <you>:add-duckfn-quantstats

The maintainers will run the build workflows (a first-time contributor's run shows up as action_required until someone approves it — that is normal). After the merge, INSTALL duckfn_quantstats FROM community works.

Keeping it in step

repo.ref and extension.version are pinned to one release. After every release, update both in this repository's community-extension/, copy them into the community repository, and push to the same PR branch (or open a new one). just release_bump already rewrites the version field; the commit SHA is the part a human has to fill in.