Installation

Install gpui-query in a Rust GPUI app: add the crate, register the global QueryClient, and verify your setup with a first query.

gpui-query is a Cargo crate. This page covers adding it to a GPUI project, choosing the right feature flags (#feature-flags), and installing a QueryClient as a GPUI Global (/docs/api/query-client) so the hooks can share a single cache.

Add the dependency

Run cargo add in your crate:

cargo add gpui-query

or add it by hand to Cargo.toml:

[dependencies]
gpui-query = "0.2.0"

gpui-query depends on gpui as a workspace dependency. It does not ship gpui itself. Your app already brings gpui in, and gpui-query links against the same version.

Feature flags

The crate is split into four layers, each behind a feature flag:

Feature  Default  Pulls in  What it gives you
core  no  serde only  The transport-agnostic state machine (QueryResource, CachePolicy, …) with no GPUI dependency. Usable in non-GPUI code or tests.
client  yes  core + gpui  The QueryClient registry and its type-partitioned buckets.
hook  no  client  The use_query / use_mutation hooks you call from views.
persist  no  client + hook + serde_json + thiserror  Async persistence: the Persister trait, QueryClient::persist_with, the free hydrate function, and the typed (de)serializer registries. See Persistence (/docs/guides/persistence).

client is on by default, so cargo add gpui-query is enough to get the registry. To use the ergonomic hooks from your components, enable the hook feature:

[dependencies]
gpui-query = { version = "0.2.0", features = ["hook"] }

cargo add gpui-query --features hook

You almost always want hook in an application. Reach for core alone when you need the state machine without a GPUI dependency (a library, a CLI that reasons about cached state, or unit tests). Add persist when you want to save and restore the cache across restarts (gpui-query = { features = ["hook", "persist"] }).

Companion crates

Two standalone crates extend gpui-query without adding dependencies to the core:

- gpui-query-persist is a reference disk adapter. FilePersister atomically writes a PersistSnapshot to disk (JSON or bincode) with a tolerant load. cargo add gpui-query-persist. See Persistence: reference adapter (/docs/guides/persistence#reference-adapter-filepersister).
- gpui-query-http turns a server's Cache-Control header into a CachePolicy ("server wins") and layers an in-memory HttpCache over any HTTP backend. cargo add gpui-query-http. See HTTP cache headers (/docs/guides/http-caching).

Both depend on gpui-query with a narrow feature set and publish independently.

Set up the QueryClient

QueryClient is a GPUI Global. Install it once during app setup. From then on, every hook routes resource creation through it for shared caching, deduplication, and garbage collection.

use gpui_query::client::QueryClient;

fn setup_app(cx: &mut gpui::App) {
    cx.set_global(QueryClient::new());
}

QueryClient::new() uses the default policies (Ttl { ttl_ms: 60_000 }, LatestWins). Override them with with_policies and tune the garbage-collection window with with_gc_time:

use gpui_query::client::QueryClient;
use gpui_query::{CachePolicy, core::RequestPolicy};

let client = QueryClient::with_policies(
    CachePolicy::Ttl { ttl_ms: 60_000 },
    RequestPolicy::LatestWins,
)
.with_gc_time(600_000); // 10 minutes (default is 5)

cx.set_global(client);

If a hook runs before a QueryClient is installed, it falls back to creating a standalone entity. There is no shared cache, deduplication, or GC. Always install the client during app startup.

Verify it is reachable

From any context, read the client back to confirm the global is set:

# use gpui_query::client::QueryClient;
# fn doc(cx: &gpui::App) {
let _client = cx.global::<QueryClient>();
# }

That is the entire setup: add the crate, enable hook, install a QueryClient global. With that in place, the Quick Start (/docs/getting-started/quick-start) shows your first end-to-end query.

Next steps

- Quick Start (/docs/getting-started/quick-start): define a fetcher, call use_query, render data.
- Queries (/docs/api/queries): the full use_query surface and QueryResource accessors.
- Caching (/docs/guides/caching): CachePolicy, deduplication, and GC in depth.