Cargo Features

Casita separates portable data-model and format code from the native repository profile and optional frontends.

Feature table

Feature	Implies	Adds
native	—	Tokio-backed repository workflows, persistent and memory backends, collection, transfer, filesystem I/O, and native Git view operations
experimental	—	Public casita::experimental namespace for backend, format, tuning, and protocol APIs
cli	native, experimental	The casita command-line binary, including the local JSON-RPC/NDJSON service (casita ipc)
git	native	Import from a local working tree or bare Git repository through gix
git-fetch	native	Experimental read-only Git fetch planning and pack generation
git-http	git, git-fetch	Read-only Git smart-HTTP serving and Tokio networking
ssh	native	Authenticated transfer sources through the system OpenSSH client
s3	native	Experimental shared S3 storage profile and Repository::s3
fuzzing	native, experimental	Internal parser adapters for fuzz harnesses

The default feature set is cli, which includes native and experimental. An ordinary cargo build builds the casita binary. Library consumers that do not need the CLI can use default-features = false, features = ["native"].

Library consumers using default-features = false also enable experimental to access service APIs such as Git fetch, HTTP, and SSH. Optional features alone do not expose backend or protocol types at the crate root.

Common configurations

Casita has not published a tagged release. The examples below follow current development; replace branch = "main" with rev = "..." for reproducible evaluation.

# Standard library use with local repositories, without the CLI dependencies.
casita = {
  git = "https://github.com/cachix/casita",
  branch = "main",
  default-features = false,
  features = ["native"],
}

# Portable identities and filesystem data types without native I/O.
casita = {
  git = "https://github.com/cachix/casita",
  branch = "main",
  default-features = false,
}

# Local native Git import.
casita = {
  git = "https://github.com/cachix/casita",
  branch = "main",
  default-features = false,
  features = ["git"],
}

# Shared S3 storage through the application API; the storage profile is experimental.
casita = {
  git = "https://github.com/cachix/casita",
  branch = "main",
  default-features = false,
  features = ["s3"],
}

# Read-only native Git serving; `git` is implied.
casita = {
  git = "https://github.com/cachix/casita",
  branch = "main",
  default-features = false,
  features = ["git-http", "experimental"],
}

# Fetch planning and pack generation without the HTTP adapter.
casita = {
  git = "https://github.com/cachix/casita",
  branch = "main",
  default-features = false,
  features = ["git-fetch", "experimental"],
}

Repository::s3 does not require the experimental feature. Custom backend composition and the generic repository require experimental, including when using local storage.

Install CLI combinations from a source checkout with:

$ cargo install --path crates/casita
$ cargo install --path crates/casita --features ssh
$ cargo install --path crates/casita --features git
$ cargo install --path crates/casita --features git-http

What remains without native

With default-features = false, the crate still provides:

• digests, typed IDs, object keys, records, roots, and revisions;
• canonical filesystem directory and path data types, including encoding and decoding.

Adding experimental also exposes ObjectFormat, FormatRegistry, portable payload verification, IPLD formats, native Git object/view models, and Casitar framing. Implementation modules remain private in every configuration.

Persistent stores, repository orchestration, streaming Casitar adapters, filesystem workflows, transfer execution, and service adapters require native. Native operations emit tracing spans and events but never install a global subscriber, leaving filtering and collection to the embedding application. cli adds the compact/JSON subscriber used by --log-filter, --log-format, and RUST_LOG; its default filter is off.

CLI feature behavior

The CLI command tree always shows all Git subcommands. Their runtime feature requirements differ:

Operation	Required build features
General CLI, Git view inspection, Git tree checkout	cli
import -i git	cli,git
git serve	cli,git-http
Local-to-local sync	cli
SSH-source sync and the remote source process	cli,ssh on both machines

Calling import -i git or git serve from a binary without its required feature returns an explicit error rather than hiding the command from help output.

Toolchain and generated documentation

The current minimum supported Rust version is 1.94.1 and the crate uses Rust edition 2024. docs.rs metadata enables every feature so feature-gated items appear together. Reproduce that API surface locally with:

$ cargo doc --all-features --no-deps