Own trace command runtime in plugin repository

bt-daemon/Cargo.toml

@@ -9,7 +9,7 @@ description = "Embeddable Braintrust coding-agent tracing daemon."
 [features]
 default = []
 # Standalone development/test binary. Production embeds the library in `bt`.
-cli = ["dep:tracing-subscriber"]
+cli = []
 
 [[bin]]
 name = "bt-daemon"
@@ -28,15 +28,15 @@ serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 sha2 = "0.10"
 thiserror = "2"
+tempfile = "3"
 tokio = { version = "1", features = ["rt-multi-thread", "macros", "net", "io-util", "sync", "time", "process", "signal", "fs"] }
 tracing = "0.1"
-tracing-subscriber = { version = "0.3", features = ["env-filter"], optional = true }
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 uuid = { version = "1", features = ["v4", "v5"] }
 
 [dev-dependencies]
 axum = "0.8"
 bytes = "1"
 reqwest = { version = "0.12", default-features = false, features = ["json", "stream"] }
-tempfile = "3"
 wiremock = "0.6"
 zstd = "0.13"

bt-daemon/README.md

@@ -16,6 +16,10 @@ One self-contained Cargo crate, liftable to its own repo by copying
 - `src/wire` — the wire protocol module: envelope types + JSON-RPC framing.
 - `src/translate` and `src/sink` — agent state machines and Braintrust output.
 - `src/lib.rs` — the embeddable library: clap `Args` + async entry points
+- `src/trace_command.rs`, `src/trace_runtime.rs`, and `src/setup.rs` — the
+  complete mounted `bt trace` command schema, dispatch, daemon lifecycle, and
+  agent-specific persistent setup behavior. Hosts supply only credential and
+  destination-resolution services.
   (`run_serve`, `run_hook`, `run_status`, `run_import`, `run_traced`). This is what `bt`
   depends on.
 - `src/main.rs` — the standalone **`bt-daemon` binary**, compiled only with

bt-daemon/src/lib.rs

@@ -19,7 +19,10 @@ mod ids;
 mod journal;
 mod server;
 mod settings;
+mod setup;
 mod sink;
+mod trace_command;
+mod trace_runtime;
 mod transcript_import;
 mod translate;
 mod transport;
@@ -30,7 +33,10 @@ pub use command_output::{
     OutputFormat, SetupCommandOutput, StatusCommandOutput, StopCommandOutput, TraceCommandOutput,
 };
 pub use server::{AuthLease, AuthProvider, AuthResolveReason, ServeOptions};
+pub use setup::run_setup;
 pub use sink::{BraintrustSinkConfig, BraintrustSinkFactory, DebugSinkFactory, Sink, SinkFactory};
+pub use trace_command::{SetupAgent, SetupArgs, StopArgs, TraceArgs, TraceCommand};
+pub use trace_runtime::{run_trace, TraceHostContext, TraceHostServices};
 pub use translate::{
     AgentTranslator, Registry, SessionCtx, SpanOp, SpanRow, SpanType, TranslatorFactory,
 };