## Summary
This PR adds a first-class API for defining registry indexes, beyond our
existing `--index-url` and `--extra-index-url` setup.
Specifically, you now define indexes like so in a `uv.toml` or
`pyproject.toml` file:
```toml
[[tool.uv.index]]
name = "pytorch"
url = "https://download.pytorch.org/whl/cu121"
```
You can also provide indexes via `--index` and `UV_INDEX`, and override
the default index with `--default-index` and `UV_DEFAULT_INDEX`.
### Index priority
Indexes are prioritized in the order in which they're defined, such that
the first-defined index has highest priority.
Indexes are also inherited from parent configuration (e.g., the
user-level `uv.toml`), but are placed after any indexes in the current
project, matching our semantics for other array-based configuration
values.
You can mix `--index` and `--default-index` with the legacy
`--index-url` and `--extra-index-url` settings; the latter two are
merely treated as unnamed `[[tool.uv.index]]` entries.
### Index pinning
If an index includes a name (which is optional), it can then be
referenced via `tool.uv.sources`:
```toml
[[tool.uv.index]]
name = "pytorch"
url = "https://download.pytorch.org/whl/cu121"
[tool.uv.sources]
torch = { index = "pytorch" }
```
If an index is marked as `explicit = true`, it can _only_ be used via
such references, and will never be searched implicitly:
```toml
[[tool.uv.index]]
name = "pytorch"
url = "https://download.pytorch.org/whl/cu121"
explicit = true
[tool.uv.sources]
torch = { index = "pytorch" }
```
Indexes defined outside of the current project (e.g., in the user-level
`uv.toml`) can _not_ be explicitly selected.
(As of now, we only support using a single index for a given
`tool.uv.sources` definition.)
### Default index
By default, we include PyPI as the default index. This remains true even
if the user defines a `[[tool.uv.index]]` -- PyPI is still used as a
fallback. You can mark an index as `default = true` to (1) disable the
use of PyPI, and (2) bump it to the bottom of the prioritized list, such
that it's used only if a package does not exist on a prior index:
```toml
[[tool.uv.index]]
name = "pytorch"
url = "https://download.pytorch.org/whl/cu121"
default = true
```
### Name reuse
If a name is reused, the higher-priority index with that name is used,
while the lower-priority indexes are ignored entirely.
For example, given:
```toml
[[tool.uv.index]]
name = "pytorch"
url = "https://download.pytorch.org/whl/cu121"
[[tool.uv.index]]
name = "pytorch"
url = "https://test.pypi.org/simple"
```
The `https://test.pypi.org/simple` index would be ignored entirely,
since it's lower-priority than `https://download.pytorch.org/whl/cu121`
but shares the same name.
Closes#171.
## Future work
- Users should be able to provide authentication for named indexes via
environment variables.
- `uv add` should automatically write `--index` entries to the
`pyproject.toml` file.
- Users should be able to provide multiple indexes for a given package,
stratified by platform:
```toml
[tool.uv.sources]
torch = [
{ index = "cpu", markers = "sys_platform == 'darwin'" },
{ index = "gpu", markers = "sys_platform != 'darwin'" },
]
```
- Users should be able to specify a proxy URL for a given index, to
avoid writing user-specific URLs to a lockfile:
```toml
[[tool.uv.index]]
name = "test"
url = "https://private.org/simple"
proxy = "http://<omitted>/pypi/simple"
```
To enforce the 100 character line limit in markdown files introduced in
https://github.com/astral-sh/uv/pull/5635, and to automate the
formatting of markdown files, i've added prettier and formatted our
markdown files with it.
I've excluded the changelog and the generated references documentation
from this for having too many changes, but we can also include them.
I'm not particular on which style we use. My main motivations are
(major) not having to reflow markdown files myself anymore and (minor)
consistence between all markdown files. I've chosen prettier for similar
reason as we chose black, it's a single good style that's automated and
shared in the community. I do prefer prettier's style of not breaking
inside of a link name though.
This PR is in two parts, the first adds prettier to CI and documents
using it, while the second actually formats the docs. When merge
conflicts arise, we can drop the last commit and regenerate it with `npx
prettier --prose-wrap always --write BENCHMARKS.md CONTRIBUTING.md
README.md STYLE.md docs/*.md docs/concepts/**/*.md docs/guides/**/*.md
docs/pip/**/*.md`.
---------
Co-authored-by: Zanie Blue <contact@zanie.dev>
