diff --git a/codex-rs/app-server/tests/common/models_cache.rs b/codex-rs/app-server/tests/common/models_cache.rs
index 220d4615ce..2f060aadde 100644
--- a/codex-rs/app-server/tests/common/models_cache.rs
+++ b/codex-rs/app-server/tests/common/models_cache.rs
@@ -53,7 +53,6 @@ fn preset_to_info(preset: &ModelPreset, priority: i32) -> ModelInfo {
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
diff --git a/codex-rs/app-server/tests/suite/v2/model_list.rs b/codex-rs/app-server/tests/suite/v2/model_list.rs
index c6a9e025c7..7e21fb6d8e 100644
--- a/codex-rs/app-server/tests/suite/v2/model_list.rs
+++ b/codex-rs/app-server/tests/suite/v2/model_list.rs
@@ -188,7 +188,6 @@ async fn list_models_uses_chatgpt_remote_catalog_as_source_of_truth() -> Result<
                 "default_verbosity": null,
                 "apply_patch_tool_type": null,
                 "truncation_policy": {"mode": "bytes", "limit": 10_000},
-                "supports_parallel_tool_calls": false,
                 "supports_image_detail_original": false,
                 "multi_agent_version": "v2",
                 "context_window": 272_000,
diff --git a/codex-rs/codex-api/src/endpoint/models.rs b/codex-rs/codex-api/src/endpoint/models.rs
index 7e9faf6544..ecd50a0f1d 100644
--- a/codex-rs/codex-api/src/endpoint/models.rs
+++ b/codex-rs/codex-api/src/endpoint/models.rs
@@ -212,7 +212,6 @@ mod tests {
                     "default_verbosity": null,
                     "apply_patch_tool_type": null,
                     "truncation_policy": {"mode": "bytes", "limit": 10_000},
-                    "supports_parallel_tool_calls": false,
                     "supports_image_detail_original": false,
                     "context_window": 272_000,
                     "experimental_supported_tools": [],
diff --git a/codex-rs/codex-api/tests/models_integration.rs b/codex-rs/codex-api/tests/models_integration.rs
index 6d59fd4976..3b7f74c4aa 100644
--- a/codex-rs/codex-api/tests/models_integration.rs
+++ b/codex-rs/codex-api/tests/models_integration.rs
@@ -91,7 +91,6 @@ async fn models_client_hits_models_endpoint() {
             apply_patch_tool_type: None,
             web_search_tool_type: Default::default(),
             truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-            supports_parallel_tool_calls: false,
             supports_image_detail_original: false,
             context_window: Some(272_000),
             max_context_window: None,
diff --git a/codex-rs/core/src/client_tests.rs b/codex-rs/core/src/client_tests.rs
index b0f5219793..41c7dc1ab0 100644
--- a/codex-rs/core/src/client_tests.rs
+++ b/codex-rs/core/src/client_tests.rs
@@ -264,7 +264,6 @@ fn test_model_info() -> ModelInfo {
         "default_verbosity": null,
         "apply_patch_tool_type": null,
         "truncation_policy": {"mode": "bytes", "limit": 10000},
-        "supports_parallel_tool_calls": false,
         "supports_image_detail_original": false,
         "context_window": 272000,
         "auto_compact_token_limit": null,
diff --git a/codex-rs/core/src/compact_remote_request.rs b/codex-rs/core/src/compact_remote_request.rs
index b0c2299529..25f8689fd8 100644
--- a/codex-rs/core/src/compact_remote_request.rs
+++ b/codex-rs/core/src/compact_remote_request.rs
@@ -63,7 +63,7 @@ pub(super) async fn run_remote_compact_attempt(
     let prompt = Prompt {
         input: prompt_input,
         tools: tool_router.model_visible_specs(),
-        parallel_tool_calls: turn_context.model_info.supports_parallel_tool_calls,
+        parallel_tool_calls: true,
         base_instructions,
         output_schema: None,
         output_schema_strict: true,
diff --git a/codex-rs/core/src/compact_remote_v2_attempt.rs b/codex-rs/core/src/compact_remote_v2_attempt.rs
index c5d4d037ef..d66bf519be 100644
--- a/codex-rs/core/src/compact_remote_v2_attempt.rs
+++ b/codex-rs/core/src/compact_remote_v2_attempt.rs
@@ -78,7 +78,7 @@ pub(super) async fn run_remote_compact_v2_attempt(
     let prompt = Prompt {
         input,
         tools: tool_router.model_visible_specs(),
-        parallel_tool_calls: turn_context.model_info.supports_parallel_tool_calls,
+        parallel_tool_calls: true,
         base_instructions,
         output_schema: None,
         output_schema_strict: true,
diff --git a/codex-rs/core/src/session/turn.rs b/codex-rs/core/src/session/turn.rs
index 2422ba0766..6c2dc1496a 100644
--- a/codex-rs/core/src/session/turn.rs
+++ b/codex-rs/core/src/session/turn.rs
@@ -1300,7 +1300,7 @@ pub(crate) fn build_prompt(
     Prompt {
         input,
         tools: router.model_visible_specs(),
-        parallel_tool_calls: turn_context.model_info.supports_parallel_tool_calls,
+        parallel_tool_calls: true,
         base_instructions,
         output_schema: turn_context.final_output_json_schema.clone(),
         output_schema_strict: !crate::guardian::is_guardian_reviewer_source(
diff --git a/codex-rs/core/tests/suite/auto_review.rs b/codex-rs/core/tests/suite/auto_review.rs
index 513a7b54c8..9d384b090c 100644
--- a/codex-rs/core/tests/suite/auto_review.rs
+++ b/codex-rs/core/tests/suite/auto_review.rs
@@ -282,7 +282,6 @@ fn remote_model_with_auto_review_override(slug: &str, review_model: &str) -> Mod
         apply_patch_tool_type: Some(ApplyPatchToolType::Freeform),
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
diff --git a/codex-rs/core/tests/suite/client.rs b/codex-rs/core/tests/suite/client.rs
index 4a86df29ca..daaf811f1d 100644
--- a/codex-rs/core/tests/suite/client.rs
+++ b/codex-rs/core/tests/suite/client.rs
@@ -2499,7 +2499,6 @@ async fn responses_lite_sets_all_turns_context_and_disables_parallel_tool_calls(
     let TestCodex { codex, .. } = test_codex()
         .with_model_info_override("gpt-5.4", |model_info| {
             model_info.use_responses_lite = true;
-            model_info.supports_parallel_tool_calls = true;
         })
         .build(&server)
         .await?;
diff --git a/codex-rs/core/tests/suite/model_switching.rs b/codex-rs/core/tests/suite/model_switching.rs
index b233c7ccc8..dfbb6d6859 100644
--- a/codex-rs/core/tests/suite/model_switching.rs
+++ b/codex-rs/core/tests/suite/model_switching.rs
@@ -135,7 +135,6 @@ fn test_model_info(
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
@@ -1207,7 +1206,6 @@ async fn model_switch_to_smaller_model_updates_token_context_window() -> Result<
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(large_context_window),
         max_context_window: None,
diff --git a/codex-rs/core/tests/suite/models_cache_ttl.rs b/codex-rs/core/tests/suite/models_cache_ttl.rs
index 2241da1010..e8a6940f84 100644
--- a/codex-rs/core/tests/suite/models_cache_ttl.rs
+++ b/codex-rs/core/tests/suite/models_cache_ttl.rs
@@ -523,7 +523,6 @@ fn test_remote_model(slug: &str, priority: i32) -> ModelInfo {
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
diff --git a/codex-rs/core/tests/suite/personality.rs b/codex-rs/core/tests/suite/personality.rs
index 5e8b7f28a5..25b9b82005 100644
--- a/codex-rs/core/tests/suite/personality.rs
+++ b/codex-rs/core/tests/suite/personality.rs
@@ -656,7 +656,6 @@ async fn remote_model_friendly_personality_instructions_with_feature() -> anyhow
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(128_000),
         max_context_window: None,
@@ -781,7 +780,6 @@ async fn user_turn_personality_remote_model_template_includes_update_message() -
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(128_000),
         max_context_window: None,
diff --git a/codex-rs/core/tests/suite/remote_models.rs b/codex-rs/core/tests/suite/remote_models.rs
index 5268fa3193..74b7399bd2 100644
--- a/codex-rs/core/tests/suite/remote_models.rs
+++ b/codex-rs/core/tests/suite/remote_models.rs
@@ -521,7 +521,6 @@ async fn remote_models_remote_model_uses_unified_exec() -> Result<()> {
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
@@ -784,7 +783,6 @@ async fn remote_models_apply_legacy_instructions() -> Result<()> {
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
@@ -1357,7 +1355,6 @@ fn test_remote_model_with_policy(
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy,
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
diff --git a/codex-rs/core/tests/suite/responses_lite.rs b/codex-rs/core/tests/suite/responses_lite.rs
index 9876a1c4b0..3cafa0c8ff 100644
--- a/codex-rs/core/tests/suite/responses_lite.rs
+++ b/codex-rs/core/tests/suite/responses_lite.rs
@@ -532,7 +532,6 @@ async fn responses_lite_compact_request_uses_lite_transport_contract() -> Result
     let mut builder = test_codex()
         .with_model_info_override("gpt-5.4", |model_info| {
             model_info.use_responses_lite = true;
-            model_info.supports_parallel_tool_calls = true;
         })
         .with_config(|config| {
             let _ = config.features.disable(Feature::RemoteCompactionV2);
diff --git a/codex-rs/core/tests/suite/rmcp_client.rs b/codex-rs/core/tests/suite/rmcp_client.rs
index 098c5d74c8..8b2cc86f84 100644
--- a/codex-rs/core/tests/suite/rmcp_client.rs
+++ b/codex-rs/core/tests/suite/rmcp_client.rs
@@ -2281,7 +2281,6 @@ async fn stdio_image_responses_are_sanitized_for_text_only_model() -> anyhow::Re
                 apply_patch_tool_type: None,
                 web_search_tool_type: Default::default(),
                 truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-                supports_parallel_tool_calls: false,
                 supports_image_detail_original: false,
                 context_window: Some(272_000),
                 max_context_window: None,
diff --git a/codex-rs/core/tests/suite/spawn_agent_description.rs b/codex-rs/core/tests/suite/spawn_agent_description.rs
index 8cb49c11e9..83905d029b 100644
--- a/codex-rs/core/tests/suite/spawn_agent_description.rs
+++ b/codex-rs/core/tests/suite/spawn_agent_description.rs
@@ -97,7 +97,6 @@ fn test_model_info(
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
diff --git a/codex-rs/core/tests/suite/view_image.rs b/codex-rs/core/tests/suite/view_image.rs
index 7607d48da3..99f54529bc 100644
--- a/codex-rs/core/tests/suite/view_image.rs
+++ b/codex-rs/core/tests/suite/view_image.rs
@@ -1641,7 +1641,6 @@ async fn view_image_tool_returns_unsupported_message_for_text_only_model() -> an
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: None,
diff --git a/codex-rs/model-provider/src/provider.rs b/codex-rs/model-provider/src/provider.rs
index e399f98fc8..c17ee367eb 100644
--- a/codex-rs/model-provider/src/provider.rs
+++ b/codex-rs/model-provider/src/provider.rs
@@ -547,7 +547,6 @@ mod tests {
             "default_verbosity": null,
             "apply_patch_tool_type": null,
             "truncation_policy": {"mode": "bytes", "limit": 10_000},
-            "supports_parallel_tool_calls": false,
             "supports_image_detail_original": false,
             "context_window": 272_000,
             "max_context_window": 272_000,
diff --git a/codex-rs/models-manager/models.json b/codex-rs/models-manager/models.json
index fef0db08bd..3b6d62393e 100644
--- a/codex-rs/models-manager/models.json
+++ b/codex-rs/models-manager/models.json
@@ -16,7 +16,6 @@
         "mode": "tokens",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": "code_mode_only",
       "multi_agent_version": "v2",
       "use_responses_lite": true,
@@ -131,7 +130,6 @@
         "mode": "tokens",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": "code_mode_only",
       "multi_agent_version": "v2",
       "use_responses_lite": true,
@@ -244,7 +242,6 @@
         "mode": "tokens",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": "code_mode_only",
       "multi_agent_version": "v1",
       "use_responses_lite": true,
@@ -353,7 +350,6 @@
         "mode": "tokens",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": null,
       "multi_agent_version": null,
       "use_responses_lite": false,
@@ -460,7 +456,6 @@
         "mode": "tokens",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": null,
       "multi_agent_version": null,
       "use_responses_lite": false,
@@ -565,7 +560,6 @@
         "mode": "tokens",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": null,
       "multi_agent_version": null,
       "use_responses_lite": false,
@@ -665,7 +659,6 @@
         "mode": "bytes",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": null,
       "multi_agent_version": null,
       "use_responses_lite": false,
@@ -762,7 +755,6 @@
         "mode": "tokens",
         "limit": 10000
       },
-      "supports_parallel_tool_calls": true,
       "tool_mode": null,
       "multi_agent_version": null,
       "use_responses_lite": false,
diff --git a/codex-rs/models-manager/src/manager_tests.rs b/codex-rs/models-manager/src/manager_tests.rs
index 0768d1e4c4..8669a0a34f 100644
--- a/codex-rs/models-manager/src/manager_tests.rs
+++ b/codex-rs/models-manager/src/manager_tests.rs
@@ -66,7 +66,6 @@ fn remote_model_with_visibility(
             "default_verbosity": null,
             "apply_patch_tool_type": null,
             "truncation_policy": {"mode": "bytes", "limit": 10_000},
-            "supports_parallel_tool_calls": false,
             "supports_image_detail_original": false,
             "context_window": 272_000,
             "max_context_window": 272_000,
@@ -746,7 +745,6 @@ async fn get_model_info_uses_custom_catalog() {
     assert_eq!(model_info.display_name, "Overlay");
     assert_eq!(model_info.context_window, Some(272_000));
     assert!(model_info.supports_image_detail_original);
-    assert!(!model_info.supports_parallel_tool_calls);
     assert!(!model_info.used_fallback_model_metadata);
 }
 
diff --git a/codex-rs/models-manager/src/model_info.rs b/codex-rs/models-manager/src/model_info.rs
index e9dc94ff4a..ba07c61606 100644
--- a/codex-rs/models-manager/src/model_info.rs
+++ b/codex-rs/models-manager/src/model_info.rs
@@ -163,7 +163,6 @@ pub fn model_info_from_slug(slug: &str) -> ModelInfo {
         apply_patch_tool_type: None,
         web_search_tool_type: WebSearchToolType::Text,
         truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-        supports_parallel_tool_calls: false,
         supports_image_detail_original: false,
         context_window: Some(272_000),
         max_context_window: Some(272_000),
diff --git a/codex-rs/protocol/src/openai_models.rs b/codex-rs/protocol/src/openai_models.rs
index 697bc13605..fba05c6e37 100644
--- a/codex-rs/protocol/src/openai_models.rs
+++ b/codex-rs/protocol/src/openai_models.rs
@@ -420,7 +420,6 @@ pub struct ModelInfo {
     #[serde(default)]
     pub web_search_tool_type: WebSearchToolType,
     pub truncation_policy: TruncationPolicyConfig,
-    pub supports_parallel_tool_calls: bool,
     #[serde(default)]
     pub supports_image_detail_original: bool,
     #[serde(default, skip_serializing_if = "Option::is_none")]
@@ -883,7 +882,6 @@ mod tests {
             apply_patch_tool_type: None,
             web_search_tool_type: WebSearchToolType::Text,
             truncation_policy: TruncationPolicyConfig::bytes(/*limit*/ 10_000),
-            supports_parallel_tool_calls: false,
             supports_image_detail_original: false,
             context_window: None,
             max_context_window: None,
@@ -1455,7 +1453,6 @@ mod tests {
                 "mode": "bytes",
                 "limit": 10000
             },
-            "supports_parallel_tool_calls": false,
             "supports_image_detail_original": false,
             "context_window": null,
             "auto_compact_token_limit": null,
diff --git a/codex-rs/tools/src/image_detail_tests.rs b/codex-rs/tools/src/image_detail_tests.rs
index 5515248adc..0fb26c10c4 100644
--- a/codex-rs/tools/src/image_detail_tests.rs
+++ b/codex-rs/tools/src/image_detail_tests.rs
@@ -27,7 +27,6 @@ fn model_info() -> ModelInfo {
             "mode": "bytes",
             "limit": 10000
         },
-        "supports_parallel_tool_calls": false,
         "supports_image_detail_original": true,
         "context_window": null,
         "auto_compact_token_limit": null,
diff --git a/codex-rs/tools/src/tool_config_tests.rs b/codex-rs/tools/src/tool_config_tests.rs
index 49b8bee710..5bcc11fe52 100644
--- a/codex-rs/tools/src/tool_config_tests.rs
+++ b/codex-rs/tools/src/tool_config_tests.rs
@@ -36,7 +36,6 @@ fn model_with_shell_type(shell_type: ConfigShellToolType) -> ModelInfo {
         apply_patch_tool_type: None,
         web_search_tool_type: Default::default(),
         truncation_policy: TruncationPolicyConfig::tokens(/*limit*/ 1024),
-        supports_parallel_tool_calls: true,
         supports_image_detail_original: false,
         context_window: None,
         max_context_window: None,
diff --git a/codex-rs/tui/src/chatwidget/tests/helpers.rs b/codex-rs/tui/src/chatwidget/tests/helpers.rs
index 1663ff9643..a8dc6917e1 100644
--- a/codex-rs/tui/src/chatwidget/tests/helpers.rs
+++ b/codex-rs/tui/src/chatwidget/tests/helpers.rs
@@ -282,7 +282,6 @@ fn test_model_info(slug: &str, priority: i32, supports_fast_mode: bool) -> Model
         "default_verbosity": null,
         "apply_patch_tool_type": null,
         "truncation_policy": {"mode": "bytes", "limit": 10_000},
-        "supports_parallel_tool_calls": false,
         "supports_image_detail_original": false,
         "context_window": 272_000,
         "experimental_supported_tools": [],