feat(uniffi): expose the telemetry core

.cargo/config.toml

@@ -8,16 +8,18 @@ rustflags = ["-C", "target-feature=+crt-static"]
 [target.aarch64-pc-windows-msvc]
 rustflags = ["-C", "target-feature=+crt-static"]
 
+# `-headerpad_max_install_names` on macOS: Flutter's native-assets step rewrites the cdylib's
+# install name with install_name_tool, which fails without the padding.
 # `-ObjC` must also be passed to rustdoc: doctest binaries are linked by rustdoc
 # and do not inherit `rustflags`. Without it the ObjC categories in libwebrtc's
 # static lib (e.g. `NSString (StdString)`) are not loaded, and static
 # initializers such as RTCH264ProfileLevelId.mm abort at process startup.
 [target.x86_64-apple-darwin]
-rustflags = ["-C", "link-args=-ObjC"]
+rustflags = ["-C", "link-args=-ObjC -Wl,-headerpad_max_install_names"]
 rustdocflags = ["-C", "link-args=-ObjC"]
 
 [target.aarch64-apple-darwin]
-rustflags = ["-C", "link-args=-ObjC"]
+rustflags = ["-C", "link-args=-ObjC -Wl,-headerpad_max_install_names"]
 rustdocflags = ["-C", "link-args=-ObjC"]
 
 [target.aarch64-apple-ios]

.changeset/telemetry-severity-from-log-level.md

@@ -0,0 +1,5 @@
+---
+livekit-telemetry: minor
+---
+
+Convert a `log::Level` into a telemetry `Severity` with `From`, and remove the process pipeline without draining it with `global::uninstall`.

.changeset/uniffi-telemetry.md

@@ -0,0 +1,5 @@
+---
+livekit-ffi: minor
+---
+
+Expose the client telemetry core through the `core-modules` UniFFI surface (`telemetry_configure`, `telemetry_configure_pulled`, `telemetry_scope`, spans, stats and `telemetry_disable`); `log_forward_bootstrap` now copies the core's own warnings and errors into telemetry and keeps the Rust log level at `warn` or looser.

Cargo.toml

@@ -41,6 +41,7 @@ members = [
     "examples/rpc",
     "examples/save_to_disk",
     "examples/screensharing",
+    "examples/telemetry_ping",
     "examples/token_source",
     "examples/webhooks",
 ]

examples/telemetry_ping/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "telemetry_ping"
+version = "0.1.0"
+edition.workspace = true
+publish = false
+
+[dependencies]
+livekit-telemetry = { workspace = true, features = ["net"] }
+livekit-net = { workspace = true, features = ["native", "rustls-tls-native-roots"] }
+tokio = { workspace = true, features = ["rt-multi-thread", "macros"] }
+env_logger = { workspace = true }

examples/telemetry_ping/src/main.rs

@@ -0,0 +1,91 @@
+// Copyright 2026 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Records a small session through the telemetry core — an `lk.connect` span with its
+//! checkpoints, an `lk.publish`, an `lk.subscribe` ended by first media, and a custom event —
+//! and exports it.
+//!
+//! - A local OpenTelemetry collector: `LK_TELEMETRY_ENDPOINT=http://localhost:4318` (the core's
+//!   test-only override; any server URL and token are accepted).
+//! - A LiveKit Cloud project: `LK_URL=wss://<project>.livekit.cloud` and `LK_TOKEN=<participant
+//!   token with the observability grant>`.
+
+use std::{env, sync::Arc};
+
+use livekit_telemetry::{
+    Attribute, NetTransport, RoomIdentity, RtcStatsSample, SpanName, SpanOutcome, SpanStep,
+    SpanTrack, StreamDirection, Telemetry, TelemetryConfig, TrackKind, TrackSource,
+    ENDPOINT_OVERRIDE_ENV,
+};
+
+#[tokio::main]
+async fn main() {
+    env_logger::init();
+    let url = env::var("LK_URL").unwrap_or_else(|_| "ws://localhost:7880".to_owned());
+    let token = env::var("LK_TOKEN").unwrap_or_default();
+    if env::var(ENDPOINT_OVERRIDE_ENV).is_err() && env::var("LK_URL").is_err() {
+        eprintln!("set {ENDPOINT_OVERRIDE_ENV}=http://localhost:4318, or LK_URL and LK_TOKEN");
+        return;
+    }
+
+    let config = TelemetryConfig {
+        resource: vec![
+            Attribute::new("service.name", "telemetry_ping"),
+            Attribute::new("os.name", env::consts::OS),
+        ],
+        // Optional on-disk cache: run once with the collector down, once with it up.
+        storage_dir: env::var("LK_TELEMETRY_DIR").ok(),
+        ..Default::default()
+    };
+    let transport = NetTransport::from_registry().expect("livekit-net has no HTTP client");
+    let (telemetry, exporter) = Telemetry::new(config, Arc::new(transport));
+    tokio::spawn(exporter.run());
+
+    let room = telemetry.begin_scope();
+    room.set_server(&url, &token);
+    room.set_room(RoomIdentity { name: Some("telemetry-ping".into()), ..Default::default() });
+
+    let connect = room.start(SpanName::Connect, None);
+    for step in [SpanStep::WsOpen, SpanStep::Signal, SpanStep::JoinRecv, SpanStep::PcCreated] {
+        connect.step(step);
+    }
+    connect.end(SpanOutcome::Ok, None);
+
+    let microphone = SpanTrack {
+        sid: Some("TR_ping_mic".into()),
+        kind: TrackKind::Audio,
+        source: TrackSource::Microphone,
+        remote_identity: None,
+    };
+    let publish = room.start(SpanName::Publish, None);
+    publish.set_track(microphone);
+    publish.end(SpanOutcome::Ok, None);
+
+    let remote = SpanTrack {
+        sid: Some("TR_ping_remote".into()),
+        kind: TrackKind::Video,
+        source: TrackSource::Camera,
+        remote_identity: Some("bob".into()),
+    };
+    room.subscribe_started(remote.clone());
+    room.subscribed(remote);
+    let mut media =
+        RtcStatsSample::new("TR_ping_remote", TrackKind::Video, StreamDirection::Inbound);
+    media.bytes = Some(1_500);
+    room.record_stats(media); // first media: the lk.subscribe span ends ok
+
+    room.emit_custom("ping", vec![Attribute::new("seq", 1i64)]);
+    telemetry.shutdown().await;
+    println!("trace {} — {}", room.trace_id(), telemetry.stats());
+}

livekit-ffi/Cargo.toml

@@ -45,6 +45,7 @@ core-modules = [
   "dep:livekit-data-stream",
   "dep:livekit-datatrack",
   "dep:livekit-net",
+  "dep:livekit-telemetry",
   "dep:livekit-token",
   "dep:prost",
   "dep:async-trait",
@@ -53,6 +54,8 @@ core-modules = [
   "livekit-common/uniffi",
   "livekit-datatrack/uniffi",
   "livekit-net/uniffi",
+  "livekit-telemetry/net",
+  "livekit-telemetry/uniffi",
   "uniffi/tokio",
 ]
 
@@ -97,6 +100,7 @@ livekit-common = { workspace = true, optional = true }
 livekit-token = { workspace = true, optional = true }
 livekit-datatrack = { workspace = true, optional = true }
 livekit-net = { workspace = true, optional = true }
+livekit-telemetry = { workspace = true, optional = true }
 livekit-data-stream = { workspace = true, optional = true }
 tokio-util = { version = "0.7.18", optional = true }
 once_cell = { version = "1.21.3", optional = true }
@@ -126,6 +130,7 @@ prost-build = { workspace = true, optional = true }
 webrtc-sys-build = { workspace = true, optional = true }
 
 [dev-dependencies]
+flate2 = "1"
 livekit-token = { workspace = true }
 serial_test = "3.0"