diff --git a/codex-rs/core/config.schema.json b/codex-rs/core/config.schema.json
index d207d5bd8e9a..0a92c818253f 100644
--- a/codex-rs/core/config.schema.json
+++ b/codex-rs/core/config.schema.json
@@ -647,6 +647,10 @@
         "phase_2_model": {
           "description": "Model used for memory consolidation.",
           "type": "string"
+        },
+        "use_memories": {
+          "description": "When `false`, skip injecting memory usage instructions into developer prompts.",
+          "type": "boolean"
         }
       },
       "type": "object"
diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index c511739f3a17..91b24a0f2527 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -3075,9 +3075,10 @@ impl Session {
             developer_sections.push(developer_instructions.to_string());
         }
         // Add developer instructions for memories.
-        if let Some(memory_prompt) =
-            build_memory_tool_developer_instructions(&turn_context.config.codex_home).await
-            && turn_context.features.enabled(Feature::MemoryTool)
+        if turn_context.features.enabled(Feature::MemoryTool)
+            && turn_context.config.memories.use_memories
+            && let Some(memory_prompt) =
+                build_memory_tool_developer_instructions(&turn_context.config.codex_home).await
         {
             developer_sections.push(memory_prompt);
         }
diff --git a/codex-rs/core/src/config/mod.rs b/codex-rs/core/src/config/mod.rs
index b3661fe790be..ec06f226715b 100644
--- a/codex-rs/core/src/config/mod.rs
+++ b/codex-rs/core/src/config/mod.rs
@@ -2490,6 +2490,7 @@ persistence = "none"
 
         let memories = r#"
 [memories]
+use_memories = false
 max_raw_memories_for_global = 512
 max_unused_days = 21
 max_rollout_age_days = 42
@@ -2502,6 +2503,7 @@ phase_2_model = "gpt-5"
             toml::from_str::<ConfigToml>(memories).expect("TOML deserialization should succeed");
         assert_eq!(
             Some(MemoriesToml {
+                use_memories: Some(false),
                 max_raw_memories_for_global: Some(512),
                 max_unused_days: Some(21),
                 max_rollout_age_days: Some(42),
@@ -2522,6 +2524,7 @@ phase_2_model = "gpt-5"
         assert_eq!(
             config.memories,
             MemoriesConfig {
+                use_memories: false,
                 max_raw_memories_for_global: 512,
                 max_unused_days: 21,
                 max_rollout_age_days: 42,
diff --git a/codex-rs/core/src/config/types.rs b/codex-rs/core/src/config/types.rs
index ec0bf15320bb..874d7d9667f9 100644
--- a/codex-rs/core/src/config/types.rs
+++ b/codex-rs/core/src/config/types.rs
@@ -371,6 +371,8 @@ pub struct FeedbackConfigToml {
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Default, JsonSchema)]
 #[schemars(deny_unknown_fields)]
 pub struct MemoriesToml {
+    /// When `false`, skip injecting memory usage instructions into developer prompts.
+    pub use_memories: Option<bool>,
     /// Maximum number of recent raw memories retained for global consolidation.
     pub max_raw_memories_for_global: Option<usize>,
     /// Maximum number of days since a memory was last used before it becomes ineligible for phase 2 selection.
@@ -390,6 +392,7 @@ pub struct MemoriesToml {
 /// Effective memories settings after defaults are applied.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct MemoriesConfig {
+    pub use_memories: bool,
     pub max_raw_memories_for_global: usize,
     pub max_unused_days: i64,
     pub max_rollout_age_days: i64,
@@ -402,6 +405,7 @@ pub struct MemoriesConfig {
 impl Default for MemoriesConfig {
     fn default() -> Self {
         Self {
+            use_memories: true,
             max_raw_memories_for_global: DEFAULT_MEMORIES_MAX_RAW_MEMORIES_FOR_GLOBAL,
             max_unused_days: DEFAULT_MEMORIES_MAX_UNUSED_DAYS,
             max_rollout_age_days: DEFAULT_MEMORIES_MAX_ROLLOUT_AGE_DAYS,
@@ -417,6 +421,7 @@ impl From<MemoriesToml> for MemoriesConfig {
     fn from(toml: MemoriesToml) -> Self {
         let defaults = Self::default();
         Self {
+            use_memories: toml.use_memories.unwrap_or(defaults.use_memories),
             max_raw_memories_for_global: toml
                 .max_raw_memories_for_global
                 .unwrap_or(defaults.max_raw_memories_for_global)