From 93f19bf780c15c7c5341f09645be33804f92417d Mon Sep 17 00:00:00 2001
From: Nathan Flurry <git@nathanflurry.com>
Date: Thu, 5 Feb 2026 23:11:45 -0800
Subject: [PATCH] feat: log session config on create

---
 server/packages/sandbox-agent/src/router.rs   | 14 +++
 .../packages/sandbox-agent/src/telemetry.rs   | 96 +++++++++++++++++--
 2 files changed, 102 insertions(+), 8 deletions(-)

diff --git a/server/packages/sandbox-agent/src/router.rs b/server/packages/sandbox-agent/src/router.rs
index 92460d5..06434a9 100644
--- a/server/packages/sandbox-agent/src/router.rs
+++ b/server/packages/sandbox-agent/src/router.rs
@@ -40,6 +40,7 @@ use utoipa::{Modify, OpenApi, ToSchema};
 
 use crate::agent_server_logs::AgentServerLogs;
 use crate::opencode_compat::{build_opencode_router, OpenCodeAppState};
+use crate::telemetry;
 use crate::ui;
 use sandbox_agent_agent_management::agents::{
     AgentError as ManagerError, AgentId, AgentManager, InstallOptions, SpawnOptions, StreamingSpawn,
@@ -1622,6 +1623,9 @@ impl SessionManager {
             session.native_session_id = Some(format!("mock-{session_id}"));
         }
 
+        let telemetry_agent = request.agent.clone();
+        let telemetry_model = request.model.clone();
+        let telemetry_variant = request.variant.clone();
         let metadata = json!({
             "agent": request.agent,
             "agentMode": session.agent_mode,
@@ -1651,6 +1655,8 @@ impl SessionManager {
         }
 
         let native_session_id = session.native_session_id.clone();
+        let telemetry_agent_mode = session.agent_mode.clone();
+        let telemetry_permission_mode = session.permission_mode.clone();
         let mut sessions = self.sessions.lock().await;
         sessions.push(session);
         drop(sessions);
@@ -1664,6 +1670,14 @@ impl SessionManager {
             self.ensure_opencode_stream(session_id).await?;
         }
 
+        telemetry::log_session_created(telemetry::SessionConfig {
+            agent: telemetry_agent,
+            agent_mode: Some(telemetry_agent_mode),
+            permission_mode: Some(telemetry_permission_mode),
+            model: telemetry_model,
+            variant: telemetry_variant,
+        });
+
         Ok(CreateSessionResponse {
             healthy: true,
             error: None,
diff --git a/server/packages/sandbox-agent/src/telemetry.rs b/server/packages/sandbox-agent/src/telemetry.rs
index 6ff221b..deaae77 100644
--- a/server/packages/sandbox-agent/src/telemetry.rs
+++ b/server/packages/sandbox-agent/src/telemetry.rs
@@ -3,6 +3,7 @@ use std::env;
 use std::fs;
 use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
 use reqwest::Client;
@@ -10,6 +11,8 @@ use serde::Serialize;
 use time::OffsetDateTime;
 use tokio::time::Instant;
 
+static TELEMETRY_ENABLED: AtomicBool = AtomicBool::new(false);
+
 const TELEMETRY_URL: &str = "https://tc.rivet.dev";
 const TELEMETRY_ENV_DEBUG: &str = "SANDBOX_AGENT_TELEMETRY_DEBUG";
 const TELEMETRY_ID_FILE: &str = "telemetry_id";
@@ -60,15 +63,17 @@ struct ProviderInfo {
 }
 
 pub fn telemetry_enabled(no_telemetry: bool) -> bool {
-    if no_telemetry {
-        return false;
-    }
-    if cfg!(debug_assertions) {
-        return env::var(TELEMETRY_ENV_DEBUG)
+    let enabled = if no_telemetry {
+        false
+    } else if cfg!(debug_assertions) {
+        env::var(TELEMETRY_ENV_DEBUG)
             .map(|value| matches!(value.as_str(), "1" | "true" | "TRUE"))
-            .unwrap_or(false);
-    }
-    true
+            .unwrap_or(false)
+    } else {
+        true
+    };
+    TELEMETRY_ENABLED.store(enabled, Ordering::Relaxed);
+    enabled
 }
 
 pub fn log_enabled_message() {
@@ -431,3 +436,78 @@ fn metadata_or_none(
         Some(map)
     }
 }
+
+#[derive(Debug, Serialize)]
+struct SessionCreatedEvent {
+    p: String,
+    dt: i64,
+    et: String,
+    eid: String,
+    ev: String,
+    d: SessionCreatedTelemetryData,
+    v: u8,
+}
+
+#[derive(Debug, Serialize)]
+struct SessionCreatedTelemetryData {
+    version: String,
+    agent: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    agent_mode: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    permission_mode: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    model: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    variant: Option<String>,
+}
+
+pub struct SessionConfig {
+    pub agent: String,
+    pub agent_mode: Option<String>,
+    pub permission_mode: Option<String>,
+    pub model: Option<String>,
+    pub variant: Option<String>,
+}
+
+pub fn log_session_created(config: SessionConfig) {
+    if !TELEMETRY_ENABLED.load(Ordering::Relaxed) {
+        return;
+    }
+
+    tokio::spawn(async move {
+        let client = match Client::builder()
+            .timeout(Duration::from_millis(TELEMETRY_TIMEOUT_MS))
+            .build()
+        {
+            Ok(client) => client,
+            Err(err) => {
+                tracing::debug!(error = %err, "failed to build telemetry client");
+                return;
+            }
+        };
+
+        let dt = OffsetDateTime::now_utc().unix_timestamp();
+        let eid = load_or_create_id();
+        let event = SessionCreatedEvent {
+            p: "sandbox-agent".to_string(),
+            dt,
+            et: "session".to_string(),
+            eid,
+            ev: "session_created".to_string(),
+            d: SessionCreatedTelemetryData {
+                version: env!("CARGO_PKG_VERSION").to_string(),
+                agent: config.agent,
+                agent_mode: config.agent_mode,
+                permission_mode: config.permission_mode,
+                model: config.model,
+                variant: config.variant,
+            },
+            v: 1,
+        };
+
+        if let Err(err) = client.post(TELEMETRY_URL).json(&event).send().await {
+            tracing::debug!(error = %err, "session telemetry request failed");
+        }
+    });
+}