diff --git a/Cargo.lock b/Cargo.lock
index a1020b14..c3b84574 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -509,7 +509,7 @@ checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
 
 [[package]]
 name = "cli-sub-agent"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -701,7 +701,7 @@ dependencies = [
 
 [[package]]
 name = "csa-acp"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "agent-client-protocol",
  "anyhow",
@@ -721,7 +721,7 @@ dependencies = [
 
 [[package]]
 name = "csa-config"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -739,7 +739,7 @@ dependencies = [
 
 [[package]]
 name = "csa-core"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "agent-teams",
  "chrono",
@@ -755,7 +755,7 @@ dependencies = [
 
 [[package]]
 name = "csa-eval"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -769,7 +769,7 @@ dependencies = [
 
 [[package]]
 name = "csa-executor"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "agent-teams",
  "anyhow",
@@ -797,7 +797,7 @@ dependencies = [
 
 [[package]]
 name = "csa-hooks"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -816,7 +816,7 @@ dependencies = [
 
 [[package]]
 name = "csa-lock"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -830,7 +830,7 @@ dependencies = [
 
 [[package]]
 name = "csa-mcp-hub"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "axum",
@@ -853,7 +853,7 @@ dependencies = [
 
 [[package]]
 name = "csa-memory"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -872,7 +872,7 @@ dependencies = [
 
 [[package]]
 name = "csa-process"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -891,7 +891,7 @@ dependencies = [
 
 [[package]]
 name = "csa-resource"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "csa-core",
@@ -907,7 +907,7 @@ dependencies = [
 
 [[package]]
 name = "csa-scheduler"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -925,7 +925,7 @@ dependencies = [
 
 [[package]]
 name = "csa-session"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -951,7 +951,7 @@ dependencies = [
 
 [[package]]
 name = "csa-todo"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "chrono",
@@ -4516,7 +4516,7 @@ dependencies = [
 
 [[package]]
 name = "weave"
-version = "0.1.736"
+version = "0.1.737"
 dependencies = [
  "anyhow",
  "clap",
diff --git a/Cargo.toml b/Cargo.toml
index 9c2a8be9..840868de 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,7 +20,7 @@ default-members = [
 resolver = "2"
 
 [workspace.package]
-version = "0.1.736"
+version = "0.1.737"
 edition = "2024"
 rust-version = "1.88"
 license = "Apache-2.0"
diff --git a/crates/cli-sub-agent/src/pipeline_post_exec.rs b/crates/cli-sub-agent/src/pipeline_post_exec.rs
index 27c3d987..600fcc74 100644
--- a/crates/cli-sub-agent/src/pipeline_post_exec.rs
+++ b/crates/cli-sub-agent/src/pipeline_post_exec.rs
@@ -56,6 +56,11 @@ pub(crate) struct PostExecContext<'a> {
     pub pre_exec_snapshot: Option<PreExecutionSnapshot>,
     /// Whether the transport observed any tool calls during execution.
     pub has_tool_calls: bool,
+    /// Number of agent conversation turns observed in this run (one per
+    /// `AgentMessage` event). `0` means the transport did not parse streaming
+    /// events; `process_execution_result` falls back to `+= 1` to preserve the
+    /// legacy "one increment per csa run" semantics.
+    pub turn_count: u32,
     /// Whether this session is running in SA (sub-agent / autonomous) mode.
     pub sa_mode: bool,
 }
@@ -109,8 +114,11 @@ pub(crate) async fn process_execution_result(
         }
     }
 
-    // Increment turn count
-    session.turn_count += 1;
+    // Increment turn count. Transports that parse streaming events (claude-code
+    // CLI, codex/gemini ACP) populate `ctx.turn_count` with the number of
+    // observed agent conversation turns; legacy transports leave it at `0` and
+    // fall back to the historical `+= 1` per-invocation contract (#1438).
+    session.turn_count = session.turn_count.saturating_add(ctx.turn_count.max(1));
 
     // Update cumulative token usage
     update_cumulative_tokens(session, token_usage);
diff --git a/crates/cli-sub-agent/src/pipeline_session_exec.rs b/crates/cli-sub-agent/src/pipeline_session_exec.rs
index 5efce0c5..25988a71 100644
--- a/crates/cli-sub-agent/src/pipeline_session_exec.rs
+++ b/crates/cli-sub-agent/src/pipeline_session_exec.rs
@@ -751,8 +751,6 @@ pub(crate) async fn execute_with_session_and_meta_with_parent_source(
             execute_events_observed,
         );
     }
-    let has_tool_calls = transport_result.metadata.has_tool_calls
-        || transport_result.metadata.has_execute_tool_calls;
     let sa_mode = std::env::var(crate::pipeline::prompt_guard::PROMPT_GUARD_CALLER_INJECTION_ENV)
         .ok()
         .map(|v| matches!(v.trim().to_ascii_lowercase().as_str(), "true" | "1"))
@@ -776,7 +774,9 @@ pub(crate) async fn execute_with_session_and_meta_with_parent_source(
         transcript_artifacts,
         changed_paths,
         pre_exec_snapshot,
-        has_tool_calls,
+        has_tool_calls: transport_result.metadata.has_tool_calls
+            || transport_result.metadata.has_execute_tool_calls,
+        turn_count: transport_result.metadata.turn_count,
         sa_mode,
     };
     if let Err(err) =
diff --git a/crates/cli-sub-agent/src/pipeline_tests_no_op_gate.rs b/crates/cli-sub-agent/src/pipeline_tests_no_op_gate.rs
index c5eb9172..41164c3a 100644
--- a/crates/cli-sub-agent/src/pipeline_tests_no_op_gate.rs
+++ b/crates/cli-sub-agent/src/pipeline_tests_no_op_gate.rs
@@ -35,6 +35,7 @@ fn build_test_ctx<'a>(
         changed_paths: vec![],
         pre_exec_snapshot: None,
         has_tool_calls,
+        turn_count: 0,
         sa_mode,
     }
 }
diff --git a/crates/cli-sub-agent/src/pipeline_tests_no_progress.rs b/crates/cli-sub-agent/src/pipeline_tests_no_progress.rs
index d16660a5..e626733d 100644
--- a/crates/cli-sub-agent/src/pipeline_tests_no_progress.rs
+++ b/crates/cli-sub-agent/src/pipeline_tests_no_progress.rs
@@ -32,6 +32,7 @@ fn build_test_ctx<'a>(
         changed_paths: vec![],
         pre_exec_snapshot: None,
         has_tool_calls: true,
+        turn_count: 0,
         sa_mode: false,
     }
 }
diff --git a/crates/cli-sub-agent/src/pipeline_tests_post_exec.rs b/crates/cli-sub-agent/src/pipeline_tests_post_exec.rs
index 03881b4d..8cfdc2e9 100644
--- a/crates/cli-sub-agent/src/pipeline_tests_post_exec.rs
+++ b/crates/cli-sub-agent/src/pipeline_tests_post_exec.rs
@@ -270,6 +270,7 @@ async fn process_execution_result_respects_vcs_auto_snapshot_gate_for_colocated_
         changed_paths: changed_paths.clone(),
         pre_exec_snapshot: None,
         has_tool_calls: true,
+        turn_count: 0,
         sa_mode: false,
     };
     let mut disabled_result = csa_process::ExecutionResult {
@@ -312,6 +313,7 @@ async fn process_execution_result_respects_vcs_auto_snapshot_gate_for_colocated_
         changed_paths,
         pre_exec_snapshot: None,
         has_tool_calls: true,
+        turn_count: 0,
         sa_mode: false,
     };
     let mut enabled_result = csa_process::ExecutionResult {
@@ -513,6 +515,7 @@ auto_capture = true
         changed_paths: vec![],
         pre_exec_snapshot: None,
         has_tool_calls: true,
+        turn_count: 0,
         sa_mode: false,
     };
     let mut result = csa_process::ExecutionResult {
diff --git a/crates/cli-sub-agent/src/pipeline_tests_post_exec_audit.rs b/crates/cli-sub-agent/src/pipeline_tests_post_exec_audit.rs
index 91c94c7f..3f3224c1 100644
--- a/crates/cli-sub-agent/src/pipeline_tests_post_exec_audit.rs
+++ b/crates/cli-sub-agent/src/pipeline_tests_post_exec_audit.rs
@@ -203,6 +203,7 @@ fn pre_execution_audit_baseline_returns_none_for_legacy_sessions_without_snapsho
         changed_paths: vec![],
         pre_exec_snapshot: None,
         has_tool_calls: false,
+        turn_count: 0,
         sa_mode: false,
     };
 
@@ -269,6 +270,7 @@ fn pre_execution_audit_baseline_prefers_per_execution_snapshot() {
             porcelain: Some(" M fresh.txt\0".to_string()),
         }),
         has_tool_calls: false,
+        turn_count: 0,
         sa_mode: false,
     };
 
@@ -362,6 +364,7 @@ fn audit_failure_does_not_fail_execution() {
         changed_paths: vec![],
         pre_exec_snapshot: None,
         has_tool_calls: false,
+        turn_count: 0,
         sa_mode: false,
     };
     let session = MetaSessionState {
@@ -484,6 +487,7 @@ fn reused_session_audit_uses_per_execution_baseline_not_session_creation() {
         changed_paths: vec![],
         pre_exec_snapshot: Some(turn_two_snapshot),
         has_tool_calls: false,
+        turn_count: 0,
         sa_mode: false,
     };
     let session = MetaSessionState {
@@ -585,6 +589,7 @@ fn first_execution_falls_back_to_session_creation_baseline_when_per_exec_capture
         changed_paths: vec![],
         pre_exec_snapshot: None,
         has_tool_calls: false,
+        turn_count: 0,
         sa_mode: false,
     };
     let session = MetaSessionState {
diff --git a/crates/csa-acp/src/client.rs b/crates/csa-acp/src/client.rs
index 14876fc7..18e2aa3b 100644
--- a/crates/csa-acp/src/client.rs
+++ b/crates/csa-acp/src/client.rs
@@ -23,6 +23,12 @@ const MAX_EXTRACTED_COMMANDS: usize = 100;
 pub struct StreamingMetadata {
     /// Total number of events seen across the entire prompt turn, including dropped events.
     pub total_events_count: usize,
+    /// Number of agent conversation turns observed (one per `AgentMessage`).
+    ///
+    /// Mirrors `csa_core::transport_events::StreamingMetadata::turn_count`; copied
+    /// through `convert_acp_metadata` in the executor crate. See that field's
+    /// docstring for the legacy fallback contract.
+    pub turn_count: u32,
     /// Whether any `ToolCallStarted` event was observed.
     pub has_tool_calls: bool,
     /// Whether any execute `ToolCallStarted` event was observed.
@@ -60,6 +66,7 @@ pub struct StreamingMetadata {
 impl StreamingMetadata {
     pub(crate) fn sync_from_store(&mut self, store: &SessionEventStore) {
         self.total_events_count = store.total_events_count();
+        self.turn_count = store.turn_count();
         self.has_tool_calls = store.has_tool_calls();
         self.has_execute_tool_calls = store.has_execute_tool_calls();
         self.has_no_verify_commit = store.has_no_verify_commit();
@@ -143,6 +150,7 @@ pub(crate) fn event_counts_as_initial_response(event: &SessionEvent) -> bool {
 pub(crate) struct SessionEventStore {
     events: VecDeque<SessionEvent>,
     total_events_count: usize,
+    turn_count: u32,
     has_tool_calls: bool,
     has_execute_tool_calls: bool,
     has_no_verify_commit: bool,
@@ -191,6 +199,10 @@ impl SessionEventStore {
         self.total_events_count
     }
 
+    pub(crate) fn turn_count(&self) -> u32 {
+        self.turn_count
+    }
+
     pub(crate) fn has_tool_calls(&self) -> bool {
         self.has_tool_calls
     }
@@ -229,8 +241,10 @@ impl SessionEventStore {
             SessionEvent::PlanUpdate(_) => {
                 self.has_plan_updates = true;
             }
-            SessionEvent::AgentMessage(_)
-            | SessionEvent::AgentThought(_)
+            SessionEvent::AgentMessage(_) => {
+                self.turn_count = self.turn_count.saturating_add(1);
+            }
+            SessionEvent::AgentThought(_)
             | SessionEvent::ToolCallCompleted { .. }
             | SessionEvent::Other(_) => {}
         }
diff --git a/crates/csa-acp/src/client/tests.rs b/crates/csa-acp/src/client/tests.rs
index c232bc7e..b8838dfc 100644
--- a/crates/csa-acp/src/client/tests.rs
+++ b/crates/csa-acp/src/client/tests.rs
@@ -204,6 +204,43 @@ fn session_event_store_bounds_retained_events_and_metadata() {
     );
 }
 
+/// `SessionEventStore` MUST count every `AgentMessage` as one conversation
+/// turn so the ACP transport can populate `StreamingMetadata.turn_count`
+/// with real turn counts rather than `csa run` invocations (#1438). The
+/// count must survive ring-buffer eviction (it is metadata, not an event).
+#[test]
+fn session_event_store_turn_count_tracks_agent_messages_and_survives_eviction() {
+    let mut store = SessionEventStore::default();
+    for i in 0..3 {
+        store.push(SessionEvent::AgentMessage(format!("turn-{i}")));
+        store.push(SessionEvent::ToolCallStarted {
+            id: format!("call-{i}"),
+            title: format!("cmd-{i}"),
+            kind: "Execute".to_string(),
+        });
+        store.push(SessionEvent::ToolCallCompleted {
+            id: format!("call-{i}"),
+            status: "success".to_string(),
+        });
+    }
+    store.push(SessionEvent::AgentThought("internal".to_string()));
+    assert_eq!(
+        store.turn_count(),
+        3,
+        "three AgentMessage events => three observed turns; thought/tool events do not count"
+    );
+
+    for i in 0..(MAX_RETAINED_EVENTS + 25) {
+        store.push(SessionEvent::AgentMessage(format!("flood-{i}")));
+    }
+    let expected_turns = 3 + (MAX_RETAINED_EVENTS as u32) + 25;
+    assert_eq!(
+        store.turn_count(),
+        expected_turns,
+        "turn_count is metadata; ring-buffer eviction must not lose it"
+    );
+}
+
 #[test]
 fn session_event_store_keeps_no_verify_sticky_after_command_ring_eviction() {
     let mut store = SessionEventStore::default();
diff --git a/crates/csa-core/src/transport_events.rs b/crates/csa-core/src/transport_events.rs
index 045592c1..d733baca 100644
--- a/crates/csa-core/src/transport_events.rs
+++ b/crates/csa-core/src/transport_events.rs
@@ -3,6 +3,15 @@
 pub struct StreamingMetadata {
     /// Total number of events seen across the entire prompt turn, including dropped events.
     pub total_events_count: usize,
+    /// Number of agent conversation turns observed in this prompt run.
+    ///
+    /// Counted by transports as the number of `AgentMessage` events emitted by
+    /// the underlying tool. A single `csa run` invocation may span many turns
+    /// when the agent reads tool results, deliberates, and responds again.
+    /// Transports that do not parse streaming events leave this at `0`; callers
+    /// must treat `0` as "unknown" and fall back to a `+= 1` increment for
+    /// `MetaSessionState.turn_count` to preserve the legacy counting contract.
+    pub turn_count: u32,
     /// Whether any `ToolCallStarted` event was observed.
     pub has_tool_calls: bool,
     /// Whether any execute `ToolCallStarted` event was observed.
diff --git a/crates/csa-executor/src/transport.rs b/crates/csa-executor/src/transport.rs
index 84c5cba6..51415dde 100644
--- a/crates/csa-executor/src/transport.rs
+++ b/crates/csa-executor/src/transport.rs
@@ -741,6 +741,7 @@ fn convert_acp_metadata(
 ) -> csa_core::transport_events::StreamingMetadata {
     csa_core::transport_events::StreamingMetadata {
         total_events_count: metadata.total_events_count,
+        turn_count: metadata.turn_count,
         has_tool_calls: metadata.has_tool_calls,
         has_execute_tool_calls: metadata.has_execute_tool_calls,
         has_no_verify_commit: metadata.has_no_verify_commit,
diff --git a/crates/csa-executor/src/transport_cli.rs b/crates/csa-executor/src/transport_cli.rs
index e74ca2c0..d2358dfa 100644
--- a/crates/csa-executor/src/transport_cli.rs
+++ b/crates/csa-executor/src/transport_cli.rs
@@ -562,6 +562,7 @@ fn parse_stream_json(buffer: &str) -> StreamParseResult {
             }
             SessionEvent::AgentMessage(text) => {
                 result.metadata.message_text.push_str(text);
+                result.metadata.turn_count = result.metadata.turn_count.saturating_add(1);
             }
             SessionEvent::AgentThought(text) => {
                 result.metadata.thought_text.push_str(text);
diff --git a/crates/csa-executor/src/transport_cli_tests.rs b/crates/csa-executor/src/transport_cli_tests.rs
index 41042a0f..b442a6d8 100644
--- a/crates/csa-executor/src/transport_cli_tests.rs
+++ b/crates/csa-executor/src/transport_cli_tests.rs
@@ -358,6 +358,42 @@ fn parse_stream_json_happy_path_emits_events() {
     assert!(parsed.metadata.has_execute_tool_calls);
     assert_eq!(parsed.metadata.total_events_count, 5);
     assert_eq!(parsed.metadata.message_text, "Hello");
+    assert_eq!(
+        parsed.metadata.turn_count, 1,
+        "one assistant envelope => one observed turn (#1438)"
+    );
+}
+
+/// `parse_stream_json` MUST count every `assistant` envelope as one
+/// observed conversation turn so `MetaSessionState.turn_count` reflects
+/// actual turns rather than `csa run` invocations (#1438). Before the
+/// fix, multi-turn streams (read tool result → think → respond again)
+/// left `turn_count` at `0` and downstream pipeline added a single
+/// `+= 1` per invocation regardless of how many turns the agent took.
+#[test]
+fn parse_stream_json_counts_each_assistant_message_as_turn() {
+    let stream = concat!(
+        r#"{"type":"system","session_id":"sess-multi","subtype":"init"}"#,
+        "\n",
+        r#"{"type":"assistant","session_id":"sess-multi","message":{"content":[{"type":"text","text":"first"}]}}"#,
+        "\n",
+        r#"{"type":"tool_use","session_id":"sess-multi","tool_use_id":"tu-1","name":"Read"}"#,
+        "\n",
+        r#"{"type":"tool_result","session_id":"sess-multi","tool_use_id":"tu-1","status":"success"}"#,
+        "\n",
+        r#"{"type":"assistant","session_id":"sess-multi","message":{"content":[{"type":"text","text":"second"}]}}"#,
+        "\n",
+        r#"{"type":"assistant","session_id":"sess-multi","message":{"content":[{"type":"text","text":"third"}]}}"#,
+        "\n",
+        r#"{"type":"result","session_id":"sess-multi","subtype":"final"}"#,
+        "\n",
+    );
+    let parsed = parse_stream_json(stream);
+    assert_eq!(
+        parsed.metadata.turn_count, 3,
+        "three assistant envelopes => three observed turns"
+    );
+    assert_eq!(parsed.metadata.message_text, "firstsecondthird");
 }
 
 #[test]