diff --git a/codex-rs/app-server/tests/suite/list_resume.rs b/codex-rs/app-server/tests/suite/list_resume.rs
index a4178b0873..58c887da34 100644
--- a/codex-rs/app-server/tests/suite/list_resume.rs
+++ b/codex-rs/app-server/tests/suite/list_resume.rs
@@ -174,7 +174,8 @@ fn create_fake_rollout(codex_home: &Path, filename_ts: &str, meta_rfc3339: &str,
                 "cwd": "/",
                 "originator": "codex",
                 "cli_version": "0.0.0",
-                "instructions": null
+                "instructions": null,
+                "model_provider": "test-provider"
             }
         })
         .to_string(),
diff --git a/codex-rs/core/src/rollout/recorder.rs b/codex-rs/core/src/rollout/recorder.rs
index 95f5d479b8..ff8ab301a2 100644
--- a/codex-rs/core/src/rollout/recorder.rs
+++ b/codex-rs/core/src/rollout/recorder.rs
@@ -137,6 +137,7 @@ impl RolloutRecorder {
                         cli_version: env!("CARGO_PKG_VERSION").to_string(),
                         instructions,
                         source,
+                        model_provider: Some(config.model_provider_id.clone()),
                     }),
                 )
             }
diff --git a/codex-rs/core/src/rollout/tests.rs b/codex-rs/core/src/rollout/tests.rs
index 617e5189c2..27c8509a67 100644
--- a/codex-rs/core/src/rollout/tests.rs
+++ b/codex-rs/core/src/rollout/tests.rs
@@ -63,6 +63,7 @@ fn write_session_file(
         "cwd": ".",
         "originator": "test_originator",
         "cli_version": "test_version",
+        "model_provider": "test-provider",
     });
 
     if let Some(source) = source {
@@ -166,6 +167,7 @@ async fn test_list_conversations_latest_first() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let head_2 = vec![serde_json::json!({
         "id": u2,
@@ -175,6 +177,7 @@ async fn test_list_conversations_latest_first() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let head_1 = vec![serde_json::json!({
         "id": u1,
@@ -184,6 +187,7 @@ async fn test_list_conversations_latest_first() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
 
     let expected_cursor: Cursor =
@@ -298,6 +302,7 @@ async fn test_pagination_cursor() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let head_4 = vec![serde_json::json!({
         "id": u4,
@@ -307,6 +312,7 @@ async fn test_pagination_cursor() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let expected_cursor1: Cursor =
         serde_json::from_str(&format!("\"2025-03-04T09-00-00|{u4}\"")).unwrap();
@@ -361,6 +367,7 @@ async fn test_pagination_cursor() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let head_2 = vec![serde_json::json!({
         "id": u2,
@@ -370,6 +377,7 @@ async fn test_pagination_cursor() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let expected_cursor2: Cursor =
         serde_json::from_str(&format!("\"2025-03-02T09-00-00|{u2}\"")).unwrap();
@@ -418,6 +426,7 @@ async fn test_pagination_cursor() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let expected_cursor3: Cursor =
         serde_json::from_str(&format!("\"2025-03-01T09-00-00|{u1}\"")).unwrap();
@@ -467,6 +476,7 @@ async fn test_get_conversation_contents() {
         "originator": "test_originator",
         "cli_version": "test_version",
         "source": "vscode",
+        "model_provider": "test-provider",
     })];
     let expected_cursor: Cursor = serde_json::from_str(&format!("\"{ts}|{uuid}\"")).unwrap();
     let expected_page = ConversationsPage {
@@ -495,6 +505,7 @@ async fn test_get_conversation_contents() {
             "originator": "test_originator",
             "cli_version": "test_version",
             "source": "vscode",
+            "model_provider": "test-provider",
         }
     });
     let user_event = serde_json::json!({
@@ -532,6 +543,7 @@ async fn test_tail_includes_last_response_items() -> Result<()> {
                 originator: "test_originator".into(),
                 cli_version: "test_version".into(),
                 source: SessionSource::VSCode,
+                model_provider: Some("test-provider".into()),
             },
             git: None,
         }),
@@ -615,6 +627,7 @@ async fn test_tail_handles_short_sessions() -> Result<()> {
                 originator: "test_originator".into(),
                 cli_version: "test_version".into(),
                 source: SessionSource::VSCode,
+                model_provider: Some("test-provider".into()),
             },
             git: None,
         }),
@@ -699,6 +712,7 @@ async fn test_tail_skips_trailing_non_responses() -> Result<()> {
                 originator: "test_originator".into(),
                 cli_version: "test_version".into(),
                 source: SessionSource::VSCode,
+                model_provider: Some("test-provider".into()),
             },
             git: None,
         }),
@@ -810,6 +824,7 @@ async fn test_stable_ordering_same_second_pagination() {
             "originator": "test_originator",
             "cli_version": "test_version",
             "source": "vscode",
+            "model_provider": "test-provider",
         })]
     };
     let expected_cursor1: Cursor = serde_json::from_str(&format!("\"{ts}|{u2}\"")).unwrap();
diff --git a/codex-rs/core/tests/suite/client.rs b/codex-rs/core/tests/suite/client.rs
index 8730f1f38f..e302a1c114 100644
--- a/codex-rs/core/tests/suite/client.rs
+++ b/codex-rs/core/tests/suite/client.rs
@@ -154,7 +154,8 @@ async fn resume_includes_initial_messages_and_sends_prior_items() {
                 "instructions": "be nice",
                 "cwd": ".",
                 "originator": "test_originator",
-                "cli_version": "test_version"
+                "cli_version": "test_version",
+                "model_provider": "test-provider"
             }
         })
     )
diff --git a/codex-rs/core/tests/suite/review.rs b/codex-rs/core/tests/suite/review.rs
index 422acd922f..d4c9f66d81 100644
--- a/codex-rs/core/tests/suite/review.rs
+++ b/codex-rs/core/tests/suite/review.rs
@@ -375,7 +375,8 @@ async fn review_input_isolated_from_parent_history() {
                 "instructions": null,
                 "cwd": ".",
                 "originator": "test_originator",
-                "cli_version": "test_version"
+                "cli_version": "test_version",
+                "model_provider": "test-provider"
             }
         });
         f.write_all(format!("{meta_line}\n").as_bytes())
diff --git a/codex-rs/core/tests/suite/rollout_list_find.rs b/codex-rs/core/tests/suite/rollout_list_find.rs
index a38f0565c0..1d40718d4b 100644
--- a/codex-rs/core/tests/suite/rollout_list_find.rs
+++ b/codex-rs/core/tests/suite/rollout_list_find.rs
@@ -28,7 +28,8 @@ fn write_minimal_rollout_with_id(codex_home: &Path, id: Uuid) -> PathBuf {
                 "instructions": null,
                 "cwd": ".",
                 "originator": "test",
-                "cli_version": "test"
+                "cli_version": "test",
+                "model_provider": "test-provider"
             }
         })
     )
diff --git a/codex-rs/protocol/src/protocol.rs b/codex-rs/protocol/src/protocol.rs
index 105f028049..244c499614 100644
--- a/codex-rs/protocol/src/protocol.rs
+++ b/codex-rs/protocol/src/protocol.rs
@@ -933,6 +933,7 @@ pub struct SessionMeta {
     pub instructions: Option<String>,
     #[serde(default)]
     pub source: SessionSource,
+    pub model_provider: Option<String>,
 }
 
 impl Default for SessionMeta {
@@ -945,6 +946,7 @@ impl Default for SessionMeta {
             cli_version: String::new(),
             instructions: None,
             source: SessionSource::default(),
+            model_provider: None,
         }
     }
 }