feat: integrate workspace memory settings authority

crates/manifest/src/config.rs

@@ -748,6 +748,8 @@ impl MemoryConfig {
             query_result_limit: upper.query_result_limit.or(self.query_result_limit),
             query_excerpt_lines: upper.query_excerpt_lines.or(self.query_excerpt_lines),
             inject_summary: upper.inject_summary.or(self.inject_summary),
+            workspace_id: upper.workspace_id.or(self.workspace_id),
+            settings_revision: upper.settings_revision.or(self.settings_revision),
             language: upper.language.or(self.language),
             extract_model: upper.extract_model.or(self.extract_model),
             extract_threshold: upper.extract_threshold.or(self.extract_threshold),

crates/manifest/src/defaults.rs

@@ -95,7 +95,3 @@ pub const COMPACT_DEFAULT_REFERENCE_COUNT: usize = 5;
 /// Optional maximum extract-worker tool-loop depth. `None` means unlimited.
 /// See [`crate::MemoryConfig::extract_worker_max_turns`].
 pub const MEMORY_EXTRACT_WORKER_MAX_TURNS: Option<u32> = Some(8);
-
-/// Default language used by memory extraction / consolidation workers for
-/// durable memory text. See [`crate::MemoryConfig::language`].
-pub const MEMORY_LANGUAGE: &str = "English";

crates/manifest/src/lib.rs

@@ -449,6 +449,29 @@ pub struct WebFetchConfig {
     pub allow_private_addresses: Option<bool>,
 }
 
+/// Maximum Unicode scalar values accepted in a normalized Workspace Memory language name.
+pub const MAX_WORKSPACE_MEMORY_LANGUAGE_CHARS: usize = 64;
+
+/// Return whether a Workspace Memory language is already normalized and safe to persist.
+pub fn is_normalized_workspace_memory_language(language: &str) -> bool {
+    !language.is_empty()
+        && language == language.trim()
+        && language.chars().count() <= MAX_WORKSPACE_MEMORY_LANGUAGE_CHARS
+        && !language.chars().any(char::is_control)
+}
+
+/// Immutable Workspace Memory settings bound into a Worker launch snapshot.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct WorkspaceMemorySettingsSnapshot {
+    /// Workspace that owns the settings revision.
+    pub workspace_id: String,
+    /// Monotonic Workspace Memory settings revision.
+    pub settings_revision: u64,
+    /// Normalized language used for Memory extraction and consolidation output.
+    pub language: String,
+}
+
 /// Memory subsystem configuration. Presence in the manifest enables
 /// memory; `workspace_root` pins the memory workspace explicitly. When it
 /// is absent, memory resolution searches upward from the Worker's pwd for a
@@ -477,11 +500,14 @@ pub struct MemoryConfig {
     /// system-prompt section. `None` ⇒ enabled.
     #[serde(default)]
     pub inject_summary: Option<bool>,
-    /// Language used by memory extraction / consolidation sub_worker for durable
-    /// memory text. Free-form so workspaces can use names like
-    /// `English`, `Japanese`, or locale tags. `None` ⇒
-    /// [`defaults::MEMORY_LANGUAGE`].
-    #[serde(default)]
+    /// Workspace that owns the bound Memory settings revision.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub workspace_id: Option<String>,
+    /// Monotonic revision of the bound Workspace Memory settings.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub settings_revision: Option<u64>,
+    /// Language from the bound Workspace Memory settings revision.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
     pub language: Option<String>,
     /// Optional model for the extract worker. When `None`,
     /// the main engine model is cloned via `clone_boxed()`. Lightweight
@@ -520,6 +546,24 @@ pub struct MemoryConfig {
     pub consolidation_threshold_bytes: Option<u64>,
 }
 
+impl MemoryConfig {
+    /// Replace any untrusted manifest values with a trusted Workspace snapshot.
+    pub fn bind_workspace_settings(&mut self, snapshot: &WorkspaceMemorySettingsSnapshot) {
+        self.workspace_id = Some(snapshot.workspace_id.clone());
+        self.settings_revision = Some(snapshot.settings_revision);
+        self.language = Some(snapshot.language.clone());
+    }
+
+    /// Return the complete bound Workspace settings snapshot, if every field is present.
+    pub fn workspace_settings(&self) -> Option<WorkspaceMemorySettingsSnapshot> {
+        Some(WorkspaceMemorySettingsSnapshot {
+            workspace_id: self.workspace_id.clone()?,
+            settings_revision: self.settings_revision?,
+            language: self.language.clone()?,
+        })
+    }
+}
+
 /// Worker metadata.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct WorkerMeta {
@@ -1223,6 +1267,18 @@ model_id = "claude-sonnet-4-20250514"
         );
     }
 
+    #[test]
+    fn workspace_memory_language_validation_is_bounded_free_form_utf8() {
+        assert!(is_normalized_workspace_memory_language("Français"));
+        assert!(is_normalized_workspace_memory_language("日本語"));
+        assert!(!is_normalized_workspace_memory_language(""));
+        assert!(!is_normalized_workspace_memory_language(" English "));
+        assert!(!is_normalized_workspace_memory_language("English\n"));
+        assert!(!is_normalized_workspace_memory_language(
+            &"x".repeat(MAX_WORKSPACE_MEMORY_LANGUAGE_CHARS + 1)
+        ));
+    }
+
     #[test]
     fn memory_section_with_language() {
         let toml = format!("{MINIMAL_REQUIRED}\n[memory]\nlanguage = \"Japanese\"\n");

crates/manifest/src/profile.rs

@@ -562,7 +562,7 @@ fn resolve_profile_value(
         mcp: profile.mcp,
         compaction,
         web: profile.web,
-        memory: profile.memory,
+        memory: profile.memory.map(Into::into),
         skills: profile.skills,
     };
     let config = WorkerManifestConfig::builtin_defaults().merge(config.resolve_paths(profile_dir));
@@ -582,6 +582,51 @@ fn resolve_profile_value(
     })
 }
 
+#[derive(Debug, Default, Deserialize)]
+#[serde(deny_unknown_fields)]
+struct ProfileMemoryConfig {
+    #[serde(default)]
+    workspace_root: Option<PathBuf>,
+    #[serde(default)]
+    query_result_limit: Option<usize>,
+    #[serde(default)]
+    query_excerpt_lines: Option<usize>,
+    #[serde(default)]
+    inject_summary: Option<bool>,
+    #[serde(default)]
+    extract_model: Option<ModelManifest>,
+    #[serde(default)]
+    extract_threshold: Option<u64>,
+    #[serde(default)]
+    extract_worker_max_turns: Option<u32>,
+    #[serde(default)]
+    consolidation_model: Option<ModelManifest>,
+    #[serde(default)]
+    consolidation_threshold_files: Option<usize>,
+    #[serde(default)]
+    consolidation_threshold_bytes: Option<u64>,
+}
+
+impl From<ProfileMemoryConfig> for MemoryConfig {
+    fn from(profile: ProfileMemoryConfig) -> Self {
+        Self {
+            workspace_root: profile.workspace_root,
+            query_result_limit: profile.query_result_limit,
+            query_excerpt_lines: profile.query_excerpt_lines,
+            inject_summary: profile.inject_summary,
+            workspace_id: None,
+            settings_revision: None,
+            language: None,
+            extract_model: profile.extract_model,
+            extract_threshold: profile.extract_threshold,
+            extract_worker_max_turns: profile.extract_worker_max_turns,
+            consolidation_model: profile.consolidation_model,
+            consolidation_threshold_files: profile.consolidation_threshold_files,
+            consolidation_threshold_bytes: profile.consolidation_threshold_bytes,
+        }
+    }
+}
+
 #[derive(Debug, Default, Deserialize)]
 #[serde(deny_unknown_fields)]
 struct ProfileConfig {
@@ -612,7 +657,7 @@ struct ProfileConfig {
     #[serde(default)]
     web: Option<WebConfig>,
     #[serde(default)]
-    memory: Option<MemoryConfig>,
+    memory: Option<ProfileMemoryConfig>,
     #[serde(default)]
     skills: Option<SkillsConfig>,
 }
@@ -1334,6 +1379,34 @@ mod tests {
         }
     }
 
+    #[test]
+    fn profile_rejects_workspace_memory_snapshot_authority_fields() {
+        let tmp = TempDir::new().unwrap();
+        for (field, value) in [
+            ("workspace_id", serde_json::json!("workspace-a")),
+            ("settings_revision", serde_json::json!(2)),
+            ("language", serde_json::json!("Japanese")),
+        ] {
+            let artifact = serde_json::json!({ "memory": { (field): value } });
+            let error = resolve_profile_artifact_value(
+                artifact,
+                ProfileSource::Registry {
+                    source: ProfileRegistrySource::Builtin,
+                    name: "test".to_string(),
+                    path: None,
+                    provenance: None,
+                },
+                tmp.path(),
+                "test-worker",
+            )
+            .unwrap_err();
+            assert!(
+                error.to_string().contains("unknown field"),
+                "unexpected error for {field}: {error}"
+            );
+        }
+    }
+
     #[test]
     fn builtin_companion_can_manage_workdirs() {
         let tmp = TempDir::new().unwrap();

crates/memory/src/audit.rs

@@ -177,6 +177,13 @@ impl OperationCounts {
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct MemorySettingsAudit {
+    pub workspace_id: String,
+    pub settings_revision: u64,
+    pub language: String,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct WorkerLifecycleAudit {
     pub run_id: Uuid,
@@ -185,6 +192,8 @@ pub struct WorkerLifecycleAudit {
     pub trigger: AuditTrigger,
     pub reason: String,
     #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub memory_settings: Option<MemorySettingsAudit>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
     pub model: Option<ModelAudit>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub usage: Option<UsageAudit>,
@@ -405,6 +414,7 @@ mod tests {
                 status: WorkerLifecycleStatus::Started,
                 trigger: AuditTrigger::TokenThreshold,
                 reason: "tokens_threshold_reached".to_string(),
+                memory_settings: None,
                 model: None,
                 usage: None,
                 extract: None,

crates/worker-runtime/src/catalog.rs

@@ -174,6 +174,9 @@ pub struct CreateWorkerRequest {
     pub worker_observation_grants: Vec<RuntimeWorkerRef>,
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub workspace_api: Option<WorkspaceApiRef>,
+    /// Backend-authored immutable Workspace Memory settings snapshot.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub memory_settings: Option<manifest::WorkspaceMemorySettingsSnapshot>,
 }
 
 /// Worker lifecycle status for the in-memory embedded runtime.

crates/worker-runtime/src/http_server.rs

@@ -1882,6 +1882,11 @@ mod tests {
             workspace_id: workspace_id.to_string(),
             base_url: format!("https://workspace.example/{workspace_id}"),
         });
+        request.memory_settings = Some(manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: workspace_id.to_string(),
+            settings_revision: 1,
+            language: "English".to_string(),
+        });
         request
     }
 
@@ -2193,6 +2198,11 @@ mod tests {
             worker_observation_enabled: false,
             worker_observation_grants: Vec::new(),
             workspace_api: None,
+            memory_settings: Some(manifest::WorkspaceMemorySettingsSnapshot {
+                workspace_id: "local".to_string(),
+                settings_revision: 1,
+                language: "English".to_string(),
+            }),
         }
     }
 
@@ -2828,6 +2838,11 @@ mod ws_tests {
             worker_observation_enabled: false,
             worker_observation_grants: Vec::new(),
             workspace_api: None,
+            memory_settings: Some(manifest::WorkspaceMemorySettingsSnapshot {
+                workspace_id: "local".to_string(),
+                settings_revision: 1,
+                language: "English".to_string(),
+            }),
         }
     }
 

crates/worker-runtime/src/runtime.rs

@@ -2794,6 +2794,27 @@ fn validate_create_workspace_scope(
             )));
         }
     }
+    let snapshot = request.memory_settings.as_ref().ok_or_else(|| {
+        RuntimeError::InvalidRequest(
+            "Workspace-scoped Worker create requires a bound Memory settings snapshot".to_string(),
+        )
+    })?;
+    if snapshot.workspace_id != workspace_id {
+        return Err(RuntimeError::InvalidRequest(format!(
+            "Memory settings workspace_id {} does not match Runtime auth workspace_id {workspace_id}",
+            snapshot.workspace_id
+        )));
+    }
+    if snapshot.settings_revision == 0 {
+        return Err(RuntimeError::InvalidRequest(
+            "Memory settings revision must be at least 1".to_string(),
+        ));
+    }
+    if !manifest::is_normalized_workspace_memory_language(&snapshot.language) {
+        return Err(RuntimeError::InvalidRequest(
+            "Memory settings language must be a normalized bounded UTF-8 value".to_string(),
+        ));
+    }
     Ok(())
 }
 
@@ -3086,6 +3107,11 @@ mod tests {
             worker_observation_enabled: false,
             worker_observation_grants: Vec::new(),
             workspace_api: None,
+            memory_settings: Some(manifest::WorkspaceMemorySettingsSnapshot {
+                workspace_id: "local".to_string(),
+                settings_revision: 1,
+                language: "English".to_string(),
+            }),
         }
     }
 
@@ -3095,9 +3121,39 @@ mod tests {
             workspace_id: workspace_id.to_string(),
             base_url: format!("https://workspace.example/{workspace_id}"),
         });
+        request.memory_settings = Some(manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: workspace_id.to_string(),
+            settings_revision: 1,
+            language: "English".to_string(),
+        });
         request
     }
 
+    #[test]
+    fn workspace_create_requires_matching_normalized_memory_settings_snapshot() {
+        let mut request = scoped_task_request("memory-snapshot", "workspace-a");
+        assert!(validate_create_workspace_scope(&request, Some("workspace-a")).is_ok());
+        request.memory_settings.as_mut().unwrap().language = "Français".to_string();
+        assert!(validate_create_workspace_scope(&request, Some("workspace-a")).is_ok());
+
+        request.memory_settings = None;
+        assert!(validate_create_workspace_scope(&request, Some("workspace-a")).is_err());
+
+        request.memory_settings = Some(manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: "workspace-b".to_string(),
+            settings_revision: 1,
+            language: "English".to_string(),
+        });
+        assert!(validate_create_workspace_scope(&request, Some("workspace-a")).is_err());
+
+        request.memory_settings = Some(manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: "workspace-a".to_string(),
+            settings_revision: 2,
+            language: " english ".to_string(),
+        });
+        assert!(validate_create_workspace_scope(&request, Some("workspace-a")).is_err());
+    }
+
     fn scope(workspace_id: &str, server_id: &str) -> RuntimeWorkspaceScope {
         RuntimeWorkspaceScope::new(workspace_id, server_id)
     }
@@ -4484,7 +4540,7 @@ mod tests {
         let worker = runtime
             .create_worker_scoped(
                 &RuntimeWorkspaceScope::new("workspace-a", "server"),
-                task_request("legacy"),
+                scoped_task_request("legacy", "workspace-a"),
             )
             .unwrap();
         drop(runtime);

crates/worker-runtime/src/worker_backend.rs

@@ -642,6 +642,60 @@ fn runtime_local_workdir_session(
     ))
 }
 
+fn bind_workspace_memory_settings(
+    manifest: &mut manifest::WorkerManifest,
+    request: &CreateWorkerRequest,
+) -> Result<(), String> {
+    let Some(snapshot) = request.memory_settings.as_ref() else {
+        if request.workspace_api.is_some() {
+            return Err(
+                "Workspace Worker request is missing its bound Memory settings snapshot"
+                    .to_string(),
+            );
+        }
+        return Ok(());
+    };
+    if let Some(workspace_api) = request.workspace_api.as_ref()
+        && snapshot.workspace_id != workspace_api.workspace_id
+    {
+        return Err(format!(
+            "Memory settings workspace {} does not match Workspace API scope {}",
+            snapshot.workspace_id, workspace_api.workspace_id
+        ));
+    }
+    manifest
+        .memory
+        .get_or_insert_with(manifest::MemoryConfig::default)
+        .bind_workspace_settings(snapshot);
+    Ok(())
+}
+
+fn validate_worker_memory_settings(
+    manifest: &manifest::WorkerManifest,
+    request: &CreateWorkerRequest,
+) -> Result<(), String> {
+    let Some(expected) = request.memory_settings.as_ref() else {
+        return Ok(());
+    };
+    let actual = manifest
+        .memory
+        .as_ref()
+        .and_then(manifest::MemoryConfig::workspace_settings)
+        .ok_or_else(|| {
+            "Workspace Worker restored without its bound Memory settings snapshot".to_string()
+        })?;
+    if &actual != expected {
+        return Err(format!(
+            "Workspace Worker Memory settings snapshot mismatch: expected {} revision {}, restored {} revision {}",
+            expected.workspace_id,
+            expected.settings_revision,
+            actual.workspace_id,
+            actual.settings_revision
+        ));
+    }
+    Ok(())
+}
+
 #[async_trait]
 impl RuntimeWorkerFactory for ProfileRuntimeWorkerFactory {
     fn observe_workspace_prompt_projection(
@@ -696,7 +750,7 @@ impl RuntimeWorkerFactory for ProfileRuntimeWorkerFactory {
         let archive = self
             .resolve_profile_source_archive(&request.request.profile_source)
             .await?;
-        let (manifest, mut loader) = {
+        let (mut manifest, mut loader) = {
             let manifest = archive
                 .resolve_profile(selector, &worker_root, &worker_name)
                 .map_err(|err| format!("failed to resolve profile source archive: {err}"))?;
@@ -714,6 +768,7 @@ impl RuntimeWorkerFactory for ProfileRuntimeWorkerFactory {
                 )?
             }
         };
+        bind_workspace_memory_settings(&mut manifest, &request.request)?;
         if let Some(bundle) = request.config_bundle.as_ref()
             && let Some(resolution) =
                 self.observe_bundle_prompt_projection(bundle, observation_workspace_id.as_deref())?
@@ -750,6 +805,7 @@ impl RuntimeWorkerFactory for ProfileRuntimeWorkerFactory {
         )
         .await
         .map_err(|err| format!("failed to create Worker from profile: {err}"))?;
+        validate_worker_memory_settings(worker.manifest(), &request.request)?;
         if let Some(binding) = request.working_directory.as_ref() {
             worker.bind_workdir_session(Some(runtime_local_workdir_session(
                 &binding.working_directory.id,
@@ -856,7 +912,8 @@ impl RuntimeWorkerFactory for ProfileRuntimeWorkerFactory {
             self.embedded_worker_mutation_dispatcher.as_ref(),
             Some(self.prompt_projection_cache.clone()),
         );
-        let (manifest, loader) = Self::restore_fallback_manifest(&worker_name)?;
+        let (mut manifest, loader) = Self::restore_fallback_manifest(&worker_name)?;
+        bind_workspace_memory_settings(&mut manifest, &request.request)?;
 
         let worker_aggregate_dir = self.worker_aggregate_dir(&request.worker_ref)?;
         let session_dir = worker_aggregate_dir.join("session");
@@ -924,6 +981,7 @@ impl RuntimeWorkerFactory for ProfileRuntimeWorkerFactory {
             }
             Err(err) => return Err(format!("failed to restore Worker from metadata: {err}")),
         };
+        validate_worker_memory_settings(worker.manifest(), &request.request)?;
         let flow_transition_enabled = worker.manifest().feature.flow.enabled;
         if let Some(binding) = request.working_directory.as_ref() {
             worker.bind_workdir_session(Some(runtime_local_workdir_session(
@@ -2504,6 +2562,7 @@ mod tests {
             worker_observation_enabled: false,
             worker_observation_grants: Vec::new(),
             workspace_api: None,
+            memory_settings: None,
         }
     }
 
@@ -2765,7 +2824,7 @@ mod tests {
 
     #[tokio::test]
     #[serial_test::serial(worker_allocation)]
-    async fn restore_pending_workspace_worker_without_system_prompt_fails_closed() {
+    async fn restore_legacy_workspace_worker_without_manifest_snapshot_requires_replacement() {
         let root = tempfile::tempdir().unwrap();
         let runtime_store_dir = root.path().join("runtime");
         let worker_ref = WorkerRef::new(crate::identity::WorkerId::from_legacy_u64(1));
@@ -2774,32 +2833,6 @@ mod tests {
             .join(worker_ref.worker_id.to_string());
         let worker_name = ProfileRuntimeWorkerFactory::runtime_worker_name_for_ref(&worker_ref);
         let session_id = session_store::new_session_id();
-        let manifest = manifest::WorkerManifest::from_toml(&format!(
-            r#"
-                [worker]
-                name = "{}"
-                pwd = "{}"
-
-                [model]
-                scheme = "anthropic"
-                model_id = "test-model"
-                auth = {{ kind = "none" }}
-
-                [engine]
-                max_tokens = 100
-
-                [feature.flow]
-                enabled = true
-
-                [[scope.allow]]
-                target = "{}"
-                permission = "write"
-            "#,
-            worker_name,
-            root.path().display(),
-            root.path().display(),
-        ))
-        .unwrap();
         WorkerAggregateStore::new(&worker_aggregate_dir, &worker_name)
             .unwrap()
             .set_active(
@@ -2807,7 +2840,7 @@ mod tests {
                 Some(session_store::WorkerActiveSegmentRef::pending_segment(
                     session_id,
                 )),
-                Some(serde_json::to_value(&manifest).unwrap()),
+                None,
             )
             .unwrap();
 
@@ -2816,6 +2849,11 @@ mod tests {
             workspace_id: "workspace-restore".to_string(),
             base_url: "http://workspace.invalid".to_string(),
         });
+        request.memory_settings = Some(manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: "workspace-restore".to_string(),
+            settings_revision: 1,
+            language: "English".to_string(),
+        });
         let identity = RuntimeIdentityMaterial::generate("runtime-restore").unwrap();
         let error = match ProfileRuntimeWorkerFactory::new(root.path())
             .with_runtime_store_dir(&runtime_store_dir)
@@ -2835,10 +2873,10 @@ mod tests {
             })
             .await
         {
-            Ok(_) => panic!("pending Workspace Worker restore unexpectedly succeeded"),
+            Ok(_) => panic!("legacy Workspace Worker restore unexpectedly succeeded"),
             Err(error) => error,
         };
-        assert!(error.contains("requires operation-owned launch material"));
+        assert!(error.contains("replacement Worker is required"), "{error}");
     }
 
     #[tokio::test]

crates/worker/src/worker.rs

@@ -2163,6 +2163,33 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
         let Some(template) = self.system_prompt_template.take() else {
             return Ok(());
         };
+        let is_memory_consolidation = self.manifest.profile.as_ref().is_some_and(|snapshot| {
+            matches!(
+                &snapshot.source,
+                manifest::ProfileSource::Registry {
+                    source: manifest::ProfileRegistrySource::Builtin,
+                    name,
+                    ..
+                } if name == "memory-consolidation"
+            )
+        });
+        if is_memory_consolidation {
+            let memory_config = self.manifest.memory.as_ref().ok_or_else(|| {
+                WorkerError::InvalidState(
+                    "Memory consolidation Worker has no Memory configuration".to_string(),
+                )
+            })?;
+            let language = memory_language(memory_config)?;
+            let rendered = self
+                .prompts
+                .load_full()
+                .memory_consolidation_system(&language)?;
+            self.engine
+                .as_mut()
+                .expect("worker present")
+                .set_system_prompt(rendered);
+            return Ok(());
+        }
         let alerter = self.alerter.clone();
         let tool_names: Vec<String> = {
             let worker = self.engine.as_mut().expect("worker present");
@@ -3750,6 +3777,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
                 memory::audit::AuditTrigger::TokenThreshold,
                 Some(model_audit_from_manifest(model)),
             )
+            .with_memory_settings(&memory_cfg)
             .emit(
                 self.workspace_client(),
                 self.event_tx.as_ref(),
@@ -3780,6 +3808,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
                     memory::audit::AuditTrigger::TokenThreshold,
                     Some(model_audit_from_manifest(model)),
                 )
+                .with_memory_settings(&memory_cfg)
                 .emit(
                     self.workspace_client(),
                     self.event_tx.as_ref(),
@@ -3845,7 +3874,8 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
             memory::audit::AuditWorker::MemoryExtract,
             memory::audit::AuditTrigger::TokenThreshold,
             Some(model_audit_from_manifest(model)),
-        );
+        )
+        .with_memory_settings(memory_cfg);
         let event_tx = self.event_tx.as_ref();
 
         let pointer_snapshot = self
@@ -3997,11 +4027,11 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
                 return Err(err);
             }
         };
-        let memory_language = memory_language(memory_cfg);
+        let memory_language = memory_language(memory_cfg)?;
         let extract_system_prompt = match self
             .prompts
             .load_full()
-            .memory_extract_system(memory_language)
+            .memory_extract_system(&memory_language)
         {
             Ok(prompt) => prompt,
             Err(err) => {
@@ -4191,6 +4221,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
                 memory::audit::AuditTrigger::StagingBacklog,
                 Some(model_audit_from_manifest(model)),
             )
+            .with_memory_settings(&memory_cfg)
             .emit(
                 self.workspace_client(),
                 self.event_tx.as_ref(),
@@ -4232,6 +4263,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
                     memory::audit::AuditTrigger::StagingBacklog,
                     Some(model_audit_from_manifest(model)),
                 )
+                .with_memory_settings(&memory_cfg)
                 .emit(
                     self.workspace_client(),
                     self.event_tx.as_ref(),
@@ -4312,6 +4344,7 @@ struct WorkerAuditBase {
     worker: memory::audit::AuditWorker,
     trigger: memory::audit::AuditTrigger,
     model: Option<memory::audit::ModelAudit>,
+    memory_settings: Option<memory::audit::MemorySettingsAudit>,
 }
 
 impl WorkerAuditBase {
@@ -4325,9 +4358,22 @@ impl WorkerAuditBase {
             worker,
             trigger,
             model,
+            memory_settings: None,
         }
     }
 
+    fn with_memory_settings(mut self, memory_config: &manifest::MemoryConfig) -> Self {
+        self.memory_settings =
+            memory_config
+                .workspace_settings()
+                .map(|snapshot| memory::audit::MemorySettingsAudit {
+                    workspace_id: snapshot.workspace_id,
+                    settings_revision: snapshot.settings_revision,
+                    language: snapshot.language,
+                });
+        self
+    }
+
     async fn emit(
         &self,
         workspace_client: &dyn WorkspaceClient,
@@ -4345,6 +4391,7 @@ impl WorkerAuditBase {
             status,
             trigger: self.trigger,
             reason: reason.clone(),
+            memory_settings: self.memory_settings.clone(),
             model: self.model.clone(),
             usage,
             extract,
@@ -4391,12 +4438,14 @@ fn is_idle_consolidation_skip_reason(reason: &str) -> bool {
         || reason.starts_with("threshold_not_reached")
 }
 
-fn memory_language(cfg: &manifest::MemoryConfig) -> &str {
-    cfg.language
-        .as_deref()
-        .map(str::trim)
-        .filter(|language| !language.is_empty())
-        .unwrap_or(manifest::defaults::MEMORY_LANGUAGE)
+fn memory_language(cfg: &manifest::MemoryConfig) -> Result<String, WorkerError> {
+    cfg.workspace_settings()
+        .map(|snapshot| snapshot.language)
+        .ok_or_else(|| {
+            WorkerError::InvalidState(
+                "Memory operation requires a bound Workspace Memory settings snapshot".to_string(),
+            )
+        })
 }
 
 fn worker_language(cfg: &manifest::EngineManifest) -> &str {
@@ -4453,6 +4502,7 @@ where
         workspace_context: WorkerWorkspaceContext,
         filesystem_authority: WorkerFilesystemAuthority,
     ) -> Result<Self, WorkerError> {
+        validate_workspace_memory_snapshot(&manifest.worker.name, &manifest, &workspace_context)?;
         let common = prepare_worker_common_with_context(
             &manifest,
             &loader,
@@ -4654,6 +4704,7 @@ where
         workspace_context: WorkerWorkspaceContext,
         filesystem_authority: WorkerFilesystemAuthority,
     ) -> Result<Self, WorkerError> {
+        validate_workspace_memory_snapshot(&manifest.worker.name, &manifest, &workspace_context)?;
         let common = prepare_worker_common_with_context(
             &manifest,
             &loader,
@@ -4768,6 +4819,13 @@ where
                 .ok_or_else(|| WorkerError::WorkerMetadataMissing {
                     worker_name: worker_name.to_string(),
                 })?;
+        if workspace_context.workspace_id().is_some()
+            && metadata.resolved_manifest_snapshot.is_none()
+        {
+            return Err(WorkerError::WorkerMetadataManifestSnapshotMissing {
+                worker_name: worker_name.to_string(),
+            });
+        }
         let active = metadata
             .active
             .ok_or_else(|| WorkerError::WorkerMetadataInactive {
@@ -4817,6 +4875,13 @@ where
                 .ok_or_else(|| WorkerError::WorkerMetadataMissing {
                     worker_name: worker_name.to_string(),
                 })?;
+        if workspace_context.workspace_id().is_some()
+            && metadata.resolved_manifest_snapshot.is_none()
+        {
+            return Err(WorkerError::WorkerMetadataManifestSnapshotMissing {
+                worker_name: worker_name.to_string(),
+            });
+        }
         let active = metadata
             .active
             .ok_or_else(|| WorkerError::WorkerMetadataInactive {
@@ -5156,8 +5221,48 @@ fn worker_metadata_for_manifest(
     metadata
 }
 
+fn validate_workspace_memory_snapshot(
+    worker_name: &str,
+    manifest: &WorkerManifest,
+    workspace_context: &WorkerWorkspaceContext,
+) -> Result<(), WorkerError> {
+    let Some(workspace_id) = workspace_context.workspace_id() else {
+        return Ok(());
+    };
+    let snapshot = manifest
+        .memory
+        .as_ref()
+        .and_then(manifest::MemoryConfig::workspace_settings)
+        .ok_or_else(|| {
+            WorkerError::InvalidState(format!(
+                "Workspace Worker {worker_name} has no complete persisted Memory settings snapshot"
+            ))
+        })?;
+    if snapshot.workspace_id != workspace_id.as_str() {
+        return Err(WorkerError::InvalidState(format!(
+            "Workspace Worker {worker_name} Memory settings belong to {} instead of {}",
+            snapshot.workspace_id,
+            workspace_id.as_str()
+        )));
+    }
+    if snapshot.settings_revision == 0
+        || !manifest::is_normalized_workspace_memory_language(&snapshot.language)
+    {
+        return Err(WorkerError::InvalidState(format!(
+            "Workspace Worker {worker_name} has corrupt Memory settings snapshot metadata"
+        )));
+    }
+    Ok(())
+}
+
 fn should_persist_resolved_manifest_snapshot(manifest: &WorkerManifest) -> bool {
-    manifest.profile.is_some() || manifest.plugins.has_resolved_plan()
+    manifest.profile.is_some()
+        || manifest.plugins.has_resolved_plan()
+        || manifest
+            .memory
+            .as_ref()
+            .and_then(manifest::MemoryConfig::workspace_settings)
+            .is_some()
 }
 
 fn restore_manifest_from_worker_metadata_snapshot(
@@ -5678,7 +5783,9 @@ pub enum WorkerError {
         session_id: SessionId,
     },
 
-    #[error("worker metadata for {worker_name} does not include a resolved manifest snapshot")]
+    #[error(
+        "worker metadata for {worker_name} does not include a trusted resolved manifest snapshot; a replacement Worker is required"
+    )]
     WorkerMetadataManifestSnapshotMissing { worker_name: String },
 
     #[error(
@@ -6179,6 +6286,92 @@ permission = "write"
         );
     }
 
+    #[test]
+    fn workspace_memory_settings_snapshot_is_persisted_and_scope_checked() {
+        let mut manifest = WorkerManifest::from_toml(
+            r#"
+[worker]
+name = "memory-snapshot"
+
+[model]
+scheme = "anthropic"
+model_id = "claude-sonnet-4-20250514"
+
+[engine]
+instruction = "default"
+
+[[scope.allow]]
+target = "/workspace"
+permission = "read"
+
+[[delegation_scope.allow]]
+target = "/workspace"
+permission = "read"
+"#,
+        )
+        .unwrap();
+        manifest.memory = Some(manifest::MemoryConfig::default());
+        manifest.memory.as_mut().unwrap().bind_workspace_settings(
+            &manifest::WorkspaceMemorySettingsSnapshot {
+                workspace_id: "workspace-a".to_string(),
+                settings_revision: 7,
+                language: "Japanese".to_string(),
+            },
+        );
+
+        let metadata = worker_metadata_for_manifest(&manifest, None, None, None);
+        let restored: WorkerManifest = serde_json::from_value(
+            metadata
+                .resolved_manifest_snapshot
+                .expect("Memory settings require a resolved manifest snapshot"),
+        )
+        .unwrap();
+        assert_eq!(
+            restored.memory.unwrap().workspace_settings(),
+            Some(manifest::WorkspaceMemorySettingsSnapshot {
+                workspace_id: "workspace-a".to_string(),
+                settings_revision: 7,
+                language: "Japanese".to_string(),
+            })
+        );
+        assert!(
+            validate_workspace_memory_snapshot(
+                "memory-snapshot",
+                &manifest,
+                &WorkerWorkspaceContext::unavailable(
+                    Some(WorkspaceId::new("workspace-a").unwrap()),
+                    "test",
+                )
+            )
+            .is_ok()
+        );
+        assert!(
+            validate_workspace_memory_snapshot(
+                "memory-snapshot",
+                &manifest,
+                &WorkerWorkspaceContext::unavailable(
+                    Some(WorkspaceId::new("workspace-b").unwrap()),
+                    "test",
+                )
+            )
+            .is_err()
+        );
+
+        let mut missing = manifest.clone();
+        missing.memory.as_mut().unwrap().settings_revision = None;
+        assert!(
+            validate_workspace_memory_snapshot(
+                "memory-snapshot",
+                &missing,
+                &WorkerWorkspaceContext::unavailable(
+                    Some(WorkspaceId::new("workspace-a").unwrap()),
+                    "test",
+                )
+            )
+            .is_err()
+        );
+    }
+
     #[test]
     fn plugin_resolved_manifest_snapshot_is_persisted_without_profile() {
         let mut manifest = WorkerManifest::from_toml(
@@ -7064,6 +7257,52 @@ mod build_summary_prompt_tests {
         }
     }
 
+    #[tokio::test]
+    async fn memory_consolidation_prompt_uses_bound_workspace_language() {
+        let dir = tempfile::tempdir().unwrap();
+        let cwd = dir.path().join("workspace");
+        std::fs::create_dir_all(&cwd).unwrap();
+        let store = session_store::FsStore::new(dir.path().join("sessions")).unwrap();
+        let mut manifest = minimal_manifest();
+        manifest.profile = Some(manifest::ProfileManifestSnapshot {
+            source: manifest::ProfileSource::Registry {
+                source: manifest::ProfileRegistrySource::Builtin,
+                name: "memory-consolidation".to_string(),
+                path: None,
+                provenance: None,
+            },
+            profile: None,
+        });
+        let mut memory = manifest::MemoryConfig::default();
+        memory.bind_workspace_settings(&manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: "workspace-test".to_string(),
+            settings_revision: 3,
+            language: "Japanese".to_string(),
+        });
+        manifest.memory = Some(memory);
+        let mut worker = Worker::new(
+            manifest,
+            Engine::new(NoopClient),
+            store,
+            WorkerWorkspaceContext::no_workspace(),
+            WorkerFilesystemAuthority::local(cwd.clone(), cwd.clone()),
+            Scope::writable(&cwd).unwrap(),
+        )
+        .await
+        .unwrap();
+        worker.set_system_prompt_template(
+            SystemPromptTemplate::parse(
+                "default",
+                crate::prompt::source::PromptCatalogSource::builtins_only(),
+            )
+            .unwrap(),
+        );
+        worker.ensure_system_prompt_materialized().await.unwrap();
+        let prompt = worker.engine().get_system_prompt().unwrap();
+        assert!(prompt.contains("`language`: `Japanese`"));
+        assert!(!prompt.contains("`language`: `English`"));
+    }
+
     async fn render_system_prompt_with_summary(
         summary_doc: Option<&str>,
         memory_config: Option<manifest::MemoryConfig>,
@@ -7358,6 +7597,9 @@ mod build_summary_prompt_tests {
         let mut manifest = minimal_manifest();
         manifest.memory = Some(manifest::MemoryConfig {
             extract_threshold: Some(1),
+            workspace_id: Some("workspace-test".to_string()),
+            settings_revision: Some(1),
+            language: Some("English".to_string()),
             ..Default::default()
         });
         let memory_config = manifest.memory.clone().unwrap();
@@ -7454,6 +7696,14 @@ mod build_summary_prompt_tests {
         assert_eq!(audits.len(), 2);
         assert_eq!(audits[0].run_id, audits[1].run_id);
         assert_eq!(audits[0].worker, memory::audit::AuditWorker::MemoryExtract);
+        assert!(audits.iter().all(|audit| {
+            audit.memory_settings
+                == Some(memory::audit::MemorySettingsAudit {
+                    workspace_id: "workspace-test".to_string(),
+                    settings_revision: 1,
+                    language: "English".to_string(),
+                })
+        }));
         assert_eq!(
             audits.iter().map(|audit| audit.status).collect::<Vec<_>>(),
             vec![

crates/workspace-api/src/lib.rs

@@ -169,6 +169,23 @@ pub struct WorkerRestoreResponse {
     pub result: WorkerRestoreResult,
 }
 
+/// Workspace-owned Memory settings returned by the shared Server API.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(deny_unknown_fields)]
+pub struct WorkspaceMemorySettings {
+    pub workspace_id: String,
+    pub settings_revision: u64,
+    pub language: String,
+}
+
+/// Compare-and-swap update for Workspace-owned Memory settings.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(deny_unknown_fields)]
+pub struct UpdateWorkspaceMemorySettingsRequest {
+    pub expected_revision: u64,
+    pub language: String,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/workspace-server/src/hosts.rs

@@ -518,6 +518,9 @@ pub struct WorkerSpawnRequest {
     pub resolved_config_bundle: Option<ConfigBundle>,
     #[serde(skip, default)]
     pub resolved_workspace_api: Option<WorkspaceApiRef>,
+    /// Backend-authored immutable Workspace Memory settings snapshot.
+    #[serde(skip, default)]
+    pub resolved_memory_settings: Option<manifest::WorkspaceMemorySettingsSnapshot>,
     /// Backend-owned feature enablement; client input cannot set it.
     #[serde(skip, default)]
     pub resolved_worker_observation_enabled: bool,
@@ -2184,6 +2187,7 @@ impl WorkspaceWorkerRuntime for EmbeddedWorkerRuntime {
             worker_observation_enabled: request.resolved_worker_observation_enabled,
             worker_observation_grants: request.resolved_worker_observation_grants.clone(),
             workspace_api: Some(workspace_api),
+            memory_settings: request.resolved_memory_settings.clone(),
         };
         let workspace_scope = RuntimeWorkspaceScope::new(workspace_id, "embedded-backend");
         match self
@@ -3331,6 +3335,7 @@ impl WorkspaceWorkerRuntime for RemoteWorkerRuntime {
             worker_observation_enabled: request.resolved_worker_observation_enabled,
             worker_observation_grants: request.resolved_worker_observation_grants.clone(),
             workspace_api: Some(workspace_api),
+            memory_settings: request.resolved_memory_settings.clone(),
         };
         match self.post_json::<_, RuntimeHttpWorkerResponse>("/v1/workers", &create) {
             Ok(response) => WorkerSpawnResult {
@@ -4408,6 +4413,14 @@ mod tests {
         }
     }
 
+    fn test_memory_settings() -> manifest::WorkspaceMemorySettingsSnapshot {
+        manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: "workspace-test".to_string(),
+            settings_revision: 1,
+            language: "English".to_string(),
+        }
+    }
+
     #[test]
     fn worker_summary_keeps_flat_wire_identity_while_using_structured_internal_identity() {
         let summary = placeholder_worker("placeholder");
@@ -5007,6 +5020,7 @@ mod tests {
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: Some(test_workspace_api()),
+            resolved_memory_settings: Some(test_memory_settings()),
         }
     }
 
@@ -5246,6 +5260,7 @@ mod tests {
                     resolved_worker_observation_grants: Vec::new(),
                     resolved_control_operation: None,
                     resolved_workspace_api: Some(test_workspace_api()),
+                    resolved_memory_settings: Some(test_memory_settings()),
                 },
             )
             .unwrap();
@@ -5345,6 +5360,7 @@ mod tests {
                     resolved_worker_observation_grants: Vec::new(),
                     resolved_control_operation: None,
                     resolved_workspace_api: Some(test_workspace_api()),
+                    resolved_memory_settings: Some(test_memory_settings()),
                 },
             )
             .unwrap();
@@ -5383,6 +5399,7 @@ mod tests {
                     resolved_worker_observation_grants: Vec::new(),
                     resolved_control_operation: None,
                     resolved_workspace_api: Some(test_workspace_api()),
+                    resolved_memory_settings: Some(test_memory_settings()),
                 },
             )
             .unwrap();

crates/workspace-server/src/runtime_subscription_tests.rs

@@ -86,6 +86,11 @@ fn create_request(name: &str) -> CreateWorkerRequest {
         worker_observation_enabled: false,
         worker_observation_grants: Vec::new(),
         workspace_api: None,
+        memory_settings: Some(manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: "local".to_string(),
+            settings_revision: 1,
+            language: "English".to_string(),
+        }),
     }
 }
 

crates/workspace-server/src/server.rs

@@ -1182,8 +1182,11 @@ impl WorkspaceApi {
                 &now_registry_timestamp(),
             )?;
         }
-        let create_fingerprint = worker_spawn_create_fingerprint(&request)
+        let request_fingerprint = worker_spawn_create_fingerprint(&request)
             .map_err(|message| Error::Config(message.to_string()))?;
+        let current_memory_settings = self
+            .config_store
+            .get_workspace_memory_settings(&self.config.workspace_id)?;
         let allocation_key = request
             .resolved_control_operation
             .as_ref()
@@ -1195,22 +1198,25 @@ impl WorkspaceApi {
                     .map(|assignment| assignment.operation_id.clone())
             })
             .unwrap_or_else(|| format!("manual:{}", WorkerId::now_v7()));
-        let worker_id = self
+        let reservation = self
             .config_store
             .reserve_worker_create(
                 &self.config.workspace_id,
                 runtime_id,
                 &allocation_key,
-                &create_fingerprint,
+                &request_fingerprint,
+                &current_memory_settings,
             )
             .map_err(|error| Error::RuntimeOperationFailed {
                 runtime_id: runtime_id.to_string(),
                 code: "workspace_worker_allocation_conflict".to_string(),
                 message: error.to_string(),
             })?;
+        let worker_id = reservation.worker_id;
+        request.resolved_memory_settings = Some(reservation.memory_settings);
         let create_binding = WorkerCreateBinding {
             worker_id,
-            create_fingerprint,
+            create_fingerprint: reservation.create_fingerprint,
         };
         let result = match self
             .runtime
@@ -1601,6 +1607,11 @@ pub fn build_router(api: WorkspaceApi) -> Router {
             "/api/w/{workspace_id}/settings/workspace",
             get(scoped_get_workspace_settings).put(scoped_update_workspace_settings),
         )
+        .route(
+            "/api/w/{workspace_id}/settings/memory",
+            get(scoped_get_workspace_memory_settings)
+                .put(scoped_update_workspace_memory_settings),
+        )
         .route(
             "/api/w/{workspace_id}/config/source-tree",
             get(scoped_get_workspace_config_tree),
@@ -2998,6 +3009,43 @@ struct WorkspaceConfigTreeResponse {
     projection_digest: String,
 }
 
+async fn scoped_get_workspace_memory_settings(
+    State(api): State<WorkspaceApi>,
+    AxumPath(workspace_id): AxumPath<String>,
+) -> ApiResult<Json<workspace_api::WorkspaceMemorySettings>> {
+    validate_workspace_scope(&api, &workspace_id)?;
+    let settings = api
+        .config_store
+        .get_workspace_memory_settings(&workspace_id)
+        .map_err(ApiError::from)?;
+    Ok(Json(workspace_api::WorkspaceMemorySettings {
+        workspace_id: settings.workspace_id,
+        settings_revision: settings.settings_revision,
+        language: settings.language,
+    }))
+}
+
+async fn scoped_update_workspace_memory_settings(
+    State(api): State<WorkspaceApi>,
+    AxumPath(workspace_id): AxumPath<String>,
+    Json(request): Json<workspace_api::UpdateWorkspaceMemorySettingsRequest>,
+) -> ApiResult<Json<workspace_api::WorkspaceMemorySettings>> {
+    validate_workspace_scope(&api, &workspace_id)?;
+    let settings = api
+        .config_store
+        .update_workspace_memory_settings(
+            &workspace_id,
+            request.expected_revision,
+            &request.language,
+        )
+        .map_err(ApiError::from)?;
+    Ok(Json(workspace_api::WorkspaceMemorySettings {
+        workspace_id: settings.workspace_id,
+        settings_revision: settings.settings_revision,
+        language: settings.language,
+    }))
+}
+
 async fn scoped_get_workspace_config_tree(
     State(api): State<WorkspaceApi>,
     AxumPath(path): AxumPath<ScopedWorkspacePath>,
@@ -6126,6 +6174,7 @@ fn start_memory_staging_consolidation(
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: None,
+            resolved_memory_settings: None,
         },
     )?;
     if result.state != WorkerOperationState::Accepted {
@@ -7192,6 +7241,7 @@ async fn scoped_start_workspace_orchestrator(
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: None,
+            resolved_memory_settings: None,
         },
     )?;
     if result.state != WorkerOperationState::Accepted || result.worker.is_none() {
@@ -9736,6 +9786,7 @@ async fn create_workspace_worker(
         resolved_worker_observation_grants: Vec::new(),
         resolved_control_operation,
         resolved_workspace_api: None,
+        resolved_memory_settings: None,
     };
     validate_ticket_assignment_spawn(&api, &runtime_id, &request)?;
     let assignment = request.ticket_assignment.clone();
@@ -13164,6 +13215,14 @@ mod tests {
         }
     }
 
+    fn test_worker_memory_settings() -> manifest::WorkspaceMemorySettingsSnapshot {
+        manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: TEST_WORKSPACE_ID.to_string(),
+            settings_revision: 1,
+            language: "English".to_string(),
+        }
+    }
+
     #[test]
     fn ticket_api_errors_preserve_http_status() {
         let not_found = ApiError::from(Error::Ticket(ticket::TicketError::NotFound(
@@ -13432,6 +13491,7 @@ mod tests {
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: None,
+            resolved_memory_settings: None,
         };
         assert!(
             api.validate_worker_spawn_repository_scope(&workdir_flow_launch)
@@ -13604,6 +13664,7 @@ mod tests {
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: None,
+            resolved_memory_settings: None,
         };
 
         assert!(
@@ -15069,6 +15130,7 @@ mod tests {
                     resolved_workspace_api: Some(test_worker_workspace_api(
                         EMBEDDED_WORKER_RUNTIME_ID,
                     )),
+                    resolved_memory_settings: Some(test_worker_memory_settings()),
                     resolved_control_operation: None,
                 },
             )
@@ -15282,6 +15344,7 @@ mod tests {
                     resolved_workspace_api: Some(test_worker_workspace_api(
                         EMBEDDED_WORKER_RUNTIME_ID,
                     )),
+                    resolved_memory_settings: Some(test_worker_memory_settings()),
                     resolved_control_operation: None,
                 },
             )
@@ -15492,6 +15555,7 @@ mod tests {
             resolved_worker_observation_enabled: false,
             resolved_worker_observation_grants: Vec::new(),
             resolved_workspace_api: Some(test_worker_workspace_api(EMBEDDED_WORKER_RUNTIME_ID)),
+            resolved_memory_settings: Some(test_worker_memory_settings()),
             resolved_control_operation: None,
         };
         let source_worker = api
@@ -15756,6 +15820,7 @@ mod tests {
                     resolved_workspace_api: Some(test_worker_workspace_api(
                         EMBEDDED_WORKER_RUNTIME_ID,
                     )),
+                    resolved_memory_settings: Some(test_worker_memory_settings()),
                     resolved_control_operation: None,
                 },
             )
@@ -15881,6 +15946,7 @@ mod tests {
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: None,
+            resolved_memory_settings: None,
         };
         let Json(first) = scoped_create_runtime_worker(
             State(api.clone()),
@@ -16045,22 +16111,28 @@ mod tests {
                 TEST_CREATED_AT,
             )
             .unwrap();
-        let reserved_worker_id = api
+        let current_memory_settings = api
+            .config_store
+            .get_workspace_memory_settings(TEST_WORKSPACE_ID)
+            .unwrap();
+        let reservation = api
             .config_store
             .reserve_worker_create(
                 TEST_WORKSPACE_ID,
                 EMBEDDED_WORKER_RUNTIME_ID,
                 "pending-spawn-operation",
                 &pending_fingerprint,
+                &current_memory_settings,
             )
             .unwrap();
+        pending_request.resolved_memory_settings = Some(reservation.memory_settings.clone());
         let spawned_before_backend_failure = api
             .runtime
             .spawn_worker(
                 EMBEDDED_WORKER_RUNTIME_ID,
                 WorkerCreateBinding {
-                    worker_id: reserved_worker_id,
-                    create_fingerprint: pending_fingerprint.clone(),
+                    worker_id: reservation.worker_id,
+                    create_fingerprint: reservation.create_fingerprint,
                 },
                 pending_request.clone(),
             )
@@ -16139,6 +16211,7 @@ mod tests {
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: None,
+            resolved_memory_settings: None,
         };
         let Json(created) = scoped_create_runtime_worker(
             State(api.clone()),
@@ -16504,6 +16577,32 @@ mod tests {
         test_api_with_recording_backend(workspace_root).await.0
     }
 
+    #[tokio::test]
+    async fn memory_settings_handlers_reject_foreign_workspace_path_scope() {
+        let temp = tempfile::tempdir().unwrap();
+        let api = test_api(temp.path()).await;
+        assert!(
+            scoped_get_workspace_memory_settings(
+                State(api.clone()),
+                AxumPath("workspace-foreign".to_string()),
+            )
+            .await
+            .is_err()
+        );
+        assert!(
+            scoped_update_workspace_memory_settings(
+                State(api),
+                AxumPath("workspace-foreign".to_string()),
+                Json(workspace_api::UpdateWorkspaceMemorySettingsRequest {
+                    expected_revision: 1,
+                    language: "English".to_string(),
+                }),
+            )
+            .await
+            .is_err()
+        );
+    }
+
     #[tokio::test]
     async fn destructive_worker_remove_rejects_browser_and_legacy_source_headers() {
         let headers = HeaderMap::new();
@@ -16699,6 +16798,7 @@ mod tests {
                     resolved_worker_observation_enabled: false,
                     resolved_worker_observation_grants: Vec::new(),
                     resolved_workspace_api: None,
+                    resolved_memory_settings: None,
                     resolved_control_operation: None,
                 },
             )
@@ -16755,6 +16855,7 @@ mod tests {
                     resolved_worker_observation_enabled: false,
                     resolved_worker_observation_grants: Vec::new(),
                     resolved_workspace_api: None,
+                    resolved_memory_settings: None,
                     resolved_control_operation: None,
                 },
             )
@@ -17680,6 +17781,7 @@ mod tests {
             worker_observation_enabled: false,
             worker_observation_grants: Vec::new(),
             workspace_api: None,
+            memory_settings: None,
         }
     }
 
@@ -18974,6 +19076,7 @@ mod tests {
                     resolved_workspace_api: Some(test_worker_workspace_api(
                         "embedded-worker-runtime",
                     )),
+                    resolved_memory_settings: Some(test_worker_memory_settings()),
                     resolved_control_operation: None,
                 },
             )
@@ -19493,6 +19596,7 @@ mod tests {
             resolved_worker_observation_grants: Vec::new(),
             resolved_control_operation: None,
             resolved_workspace_api: None,
+            resolved_memory_settings: None,
         };
         let spawned = api
             .spawn_workspace_worker(EMBEDDED_WORKER_RUNTIME_ID, spawn_request)

crates/workspace-server/src/store.rs

@@ -8,6 +8,7 @@ use rusqlite::{
     Connection, OpenFlags, OptionalExtension, TransactionBehavior, backup::Backup, params,
 };
 use serde::{Deserialize, Serialize};
+use sha2::{Digest, Sha256};
 use uuid::Uuid;
 
 use worker_runtime::identity::{
@@ -230,6 +231,11 @@ const MIGRATIONS: &[Migration] = &[
         name: "rename Workspace resource keys",
         apply: verify_workspace_resource_key_schema,
     },
+    Migration {
+        version: 42,
+        name: "create Workspace Memory settings authority",
+        apply: create_workspace_memory_settings_authority,
+    },
 ];
 
 struct Migration {
@@ -261,6 +267,22 @@ pub struct WorkspaceRecord {
     pub updated_at: String,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct WorkspaceMemorySettingsRecord {
+    pub workspace_id: String,
+    pub settings_revision: u64,
+    pub language: String,
+    pub created_at: String,
+    pub updated_at: String,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct WorkerCreateReservation {
+    pub worker_id: WorkerId,
+    pub create_fingerprint: String,
+    pub memory_settings: manifest::WorkspaceMemorySettingsSnapshot,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
 pub struct RepositoryRecord {
     pub workspace_id: String,
@@ -1140,23 +1162,125 @@ impl SqliteWorkspaceStore {
         f(&mut conn)
     }
 
+    pub(crate) fn get_workspace_memory_settings(
+        &self,
+        workspace_id: &str,
+    ) -> Result<WorkspaceMemorySettingsRecord> {
+        let record = self.with_conn(|conn| {
+            conn.query_row(
+                "SELECT workspace_id, settings_revision, language, created_at, updated_at \
+                 FROM workspace_memory_settings WHERE workspace_id = ?1",
+                params![workspace_id],
+                |row| {
+                    let revision = row.get::<_, i64>(1)?;
+                    Ok(WorkspaceMemorySettingsRecord {
+                        workspace_id: row.get(0)?,
+                        settings_revision: revision
+                            .try_into()
+                            .map_err(|_| rusqlite::Error::IntegralValueOutOfRange(1, revision))?,
+                        language: row.get(2)?,
+                        created_at: row.get(3)?,
+                        updated_at: row.get(4)?,
+                    })
+                },
+            )
+            .optional()?
+            .ok_or_else(|| Error::Store("Workspace Memory settings are missing".to_string()))
+        })?;
+        validate_workspace_memory_settings_record(&record, workspace_id)?;
+        Ok(record)
+    }
+
+    pub(crate) fn update_workspace_memory_settings(
+        &self,
+        workspace_id: &str,
+        expected_revision: u64,
+        language: &str,
+    ) -> Result<WorkspaceMemorySettingsRecord> {
+        let language = normalize_workspace_memory_language(language)?;
+        self.with_conn_mut(|conn| {
+            let tx = conn.transaction_with_behavior(TransactionBehavior::Immediate)?;
+            let current = tx
+                .query_row(
+                    "SELECT workspace_id, settings_revision, language, created_at, updated_at \
+                     FROM workspace_memory_settings WHERE workspace_id = ?1",
+                    params![workspace_id],
+                    |row| {
+                        let revision = row.get::<_, i64>(1)?;
+                        Ok(WorkspaceMemorySettingsRecord {
+                            workspace_id: row.get(0)?,
+                            settings_revision: revision.try_into().map_err(|_| {
+                                rusqlite::Error::IntegralValueOutOfRange(1, revision)
+                            })?,
+                            language: row.get(2)?,
+                            created_at: row.get(3)?,
+                            updated_at: row.get(4)?,
+                        })
+                    },
+                )
+                .optional()?
+                .ok_or_else(|| Error::Store("Workspace Memory settings are missing".to_string()))?;
+            validate_workspace_memory_settings_record(&current, workspace_id)?;
+            let current_revision = current.settings_revision;
+            if current_revision != expected_revision {
+                return Err(Error::WorkspaceConfigConflict(format!(
+                    "Workspace Memory settings revision changed: expected {expected_revision}, current {current_revision}"
+                )));
+            }
+            if current.language == language {
+                tx.commit()?;
+                return Ok(current);
+            }
+            let next_revision = current_revision.checked_add(1).ok_or_else(|| {
+                Error::InvalidInput("Workspace Memory settings revision overflow".to_string())
+            })?;
+            let now = chrono::Utc::now().to_rfc3339();
+            tx.execute(
+                "UPDATE workspace_memory_settings \
+                 SET settings_revision = ?2, language = ?3, updated_at = ?4 \
+                 WHERE workspace_id = ?1",
+                params![workspace_id, next_revision as i64, language, now],
+            )?;
+            let record = tx.query_row(
+                "SELECT workspace_id, settings_revision, language, created_at, updated_at \
+                 FROM workspace_memory_settings WHERE workspace_id = ?1",
+                params![workspace_id],
+                |row| {
+                    let revision = row.get::<_, i64>(1)?;
+                    Ok(WorkspaceMemorySettingsRecord {
+                        workspace_id: row.get(0)?,
+                        settings_revision: revision as u64,
+                        language: row.get(2)?,
+                        created_at: row.get(3)?,
+                        updated_at: row.get(4)?,
+                    })
+                },
+            )?;
+            tx.commit()?;
+            Ok(record)
+        })
+    }
+
     pub(crate) fn reserve_worker_create(
         &self,
         workspace_id: &str,
         runtime_id: &str,
         allocation_key: &str,
-        create_fingerprint: &str,
-    ) -> Result<WorkerId> {
-        if allocation_key.trim().is_empty() || create_fingerprint.trim().is_empty() {
+        request_fingerprint: &str,
+        current_memory_settings: &WorkspaceMemorySettingsRecord,
+    ) -> Result<WorkerCreateReservation> {
+        if allocation_key.trim().is_empty() || request_fingerprint.trim().is_empty() {
             return Err(Error::InvalidInput(
                 "Worker create allocation key and fingerprint must be non-empty".to_string(),
             ));
         }
+        validate_workspace_memory_settings_record(current_memory_settings, workspace_id)?;
         self.with_conn_mut(|conn| {
             let tx = conn.transaction_with_behavior(TransactionBehavior::Immediate)?;
             let existing = tx
                 .query_row(
-                    "SELECT worker_id, runtime_id, create_fingerprint \
+                    "SELECT worker_id, runtime_id, request_fingerprint, create_fingerprint, \
+                            memory_settings_revision, memory_language \
                      FROM worker_create_reservations \
                      WHERE workspace_id = ?1 AND allocation_key = ?2",
                     params![workspace_id, allocation_key],
@@ -1164,24 +1288,80 @@ impl SqliteWorkspaceStore {
                         Ok((
                             row.get::<_, String>(0)?,
                             row.get::<_, String>(1)?,
-                            row.get::<_, String>(2)?,
+                            row.get::<_, Option<String>>(2)?,
+                            row.get::<_, String>(3)?,
+                            row.get::<_, Option<i64>>(4)?,
+                            row.get::<_, Option<String>>(5)?,
                         ))
                     },
                 )
                 .optional()?;
-            if let Some((worker_id, reserved_runtime_id, reserved_fingerprint)) = existing {
-                if reserved_runtime_id != runtime_id || reserved_fingerprint != create_fingerprint {
+            if let Some((worker_id, reserved_runtime_id, stored_request_fingerprint, create_fingerprint, revision, language)) = existing {
+                if reserved_runtime_id != runtime_id
+                    || stored_request_fingerprint.as_deref() != Some(request_fingerprint)
+                {
                     return Err(Error::InvalidInput(format!(
-                        "Worker create allocation `{allocation_key}` was already used with different input"
+                        "Worker create allocation {allocation_key} was already used with different input"
                     )));
                 }
-                return worker_id.parse::<WorkerId>().map_err(|_| {
-                    Error::Store(format!(
-                        "Worker create allocation `{allocation_key}` has a non-UUIDv7 worker id"
+                let revision = revision.ok_or_else(|| {
+                    Error::InvalidInput(format!(
+                        "Worker create allocation {allocation_key} has no persisted Memory settings snapshot"
                     ))
+                })?;
+                let language = language.ok_or_else(|| {
+                    Error::InvalidInput(format!(
+                        "Worker create allocation {allocation_key} has no persisted Memory language"
+                    ))
+                })?;
+                let worker_id = worker_id.parse::<WorkerId>().map_err(|_| {
+                    Error::Store(format!(
+                        "Worker create allocation {allocation_key} has a non-UUIDv7 worker id"
+                    ))
+                })?;
+                let snapshot = manifest::WorkspaceMemorySettingsSnapshot {
+                    workspace_id: workspace_id.to_string(),
+                    settings_revision: revision.try_into().map_err(|_| {
+                        rusqlite::Error::IntegralValueOutOfRange(4, revision)
+                    })?,
+                    language,
+                };
+                validate_workspace_memory_settings_snapshot(&snapshot, workspace_id)?;
+                return Ok(WorkerCreateReservation {
+                    worker_id,
+                    create_fingerprint,
+                    memory_settings: snapshot,
                 });
             }
 
+            let (authoritative_revision, authoritative_language) = tx
+                .query_row(
+                    "SELECT settings_revision, language FROM workspace_memory_settings WHERE workspace_id = ?1",
+                    params![workspace_id],
+                    |row| Ok((row.get::<_, i64>(0)?, row.get::<_, String>(1)?)),
+                )
+                .optional()?
+                .ok_or_else(|| Error::Store("Workspace Memory settings are missing".to_string()))?;
+            let authoritative_revision: u64 = authoritative_revision.try_into().map_err(|_| {
+                rusqlite::Error::IntegralValueOutOfRange(0, authoritative_revision)
+            })?;
+            if authoritative_revision != current_memory_settings.settings_revision
+                || authoritative_language != current_memory_settings.language
+            {
+                return Err(Error::WorkspaceConfigConflict(
+                    "Workspace Memory settings changed while the Worker create reservation was being accepted"
+                        .to_string(),
+                ));
+            }
+
+            let snapshot = manifest::WorkspaceMemorySettingsSnapshot {
+                workspace_id: workspace_id.to_string(),
+                settings_revision: authoritative_revision,
+                language: authoritative_language,
+            };
+            validate_workspace_memory_settings_snapshot(&snapshot, workspace_id)?;
+            let create_fingerprint =
+                bound_worker_create_fingerprint(request_fingerprint, &snapshot);
             let worker_id = WorkerId::now_v7();
             let now = chrono::Utc::now().to_rfc3339();
             allocate_resource_key(
@@ -1194,19 +1374,27 @@ impl SqliteWorkspaceStore {
             tx.execute(
                 "INSERT INTO worker_create_reservations(\
                     workspace_id, allocation_key, worker_id, runtime_id, create_fingerprint,\
-                    state, created_at, updated_at\
-                 ) VALUES (?1, ?2, ?3, ?4, ?5, 'reserved', ?6, ?6)",
+                    state, created_at, updated_at, request_fingerprint,\
+                    memory_settings_revision, memory_language\
+                 ) VALUES (?1, ?2, ?3, ?4, ?5, 'reserved', ?6, ?6, ?7, ?8, ?9)",
                 params![
                     workspace_id,
                     allocation_key,
                     worker_id.to_string(),
                     runtime_id,
                     create_fingerprint,
-                    now
+                    now,
+                    request_fingerprint,
+                    snapshot.settings_revision as i64,
+                    snapshot.language,
                 ],
             )?;
             tx.commit()?;
-            Ok(worker_id)
+            Ok(WorkerCreateReservation {
+                worker_id,
+                create_fingerprint,
+                memory_settings: snapshot,
+            })
         })
     }
 
@@ -1375,8 +1563,9 @@ impl ControlPlaneStore for SqliteWorkspaceStore {
     }
 
     async fn upsert_workspace(&self, record: &WorkspaceRecord) -> Result<()> {
-        self.with_conn(|conn| {
-            conn.execute(
+        self.with_conn_mut(|conn| {
+            let tx = conn.transaction_with_behavior(TransactionBehavior::Immediate)?;
+            tx.execute(
                 r#"INSERT INTO workspaces (
                     workspace_id, owner_account_id, display_name, state, created_at, updated_at
                 ) VALUES (?1, ?2, ?3, ?4, ?5, ?6)
@@ -1394,6 +1583,13 @@ impl ControlPlaneStore for SqliteWorkspaceStore {
                     record.updated_at,
                 ],
             )?;
+            tx.execute(
+                r#"INSERT OR IGNORE INTO workspace_memory_settings (
+                    workspace_id, settings_revision, language, created_at, updated_at
+                ) VALUES (?1, 1, 'English', ?2, ?3)"#,
+                params![record.workspace_id, record.created_at, record.updated_at],
+            )?;
+            tx.commit()?;
             Ok(())
         })?;
         self.materialize_workspace_config(&record.workspace_id, &record.created_at)
@@ -1518,6 +1714,16 @@ impl ControlPlaneStore for SqliteWorkspaceStore {
                         record.workspace.updated_at,
                     ],
                 )?;
+                tx.execute(
+                    r#"INSERT INTO workspace_memory_settings (
+                        workspace_id, settings_revision, language, created_at, updated_at
+                    ) VALUES (?1, 1, 'English', ?2, ?3)"#,
+                    params![
+                        record.workspace.workspace_id,
+                        record.workspace.created_at,
+                        record.workspace.updated_at,
+                    ],
+                )?;
                 tx.execute(
                     r#"INSERT INTO repositories (
                         workspace_id, repository_id, name, kind, provider, uri, default_ref,
@@ -5730,6 +5936,67 @@ fn collect_reference_diagnostics(
     Ok(())
 }
 
+fn validate_workspace_memory_settings_snapshot(
+    snapshot: &manifest::WorkspaceMemorySettingsSnapshot,
+    expected_workspace_id: &str,
+) -> Result<()> {
+    if snapshot.workspace_id != expected_workspace_id
+        || snapshot.settings_revision == 0
+        || !manifest::is_normalized_workspace_memory_language(&snapshot.language)
+    {
+        return Err(Error::Store(
+            "Workspace Memory settings are corrupt or belong to another Workspace".to_string(),
+        ));
+    }
+    Ok(())
+}
+
+fn validate_workspace_memory_settings_record(
+    record: &WorkspaceMemorySettingsRecord,
+    expected_workspace_id: &str,
+) -> Result<()> {
+    validate_workspace_memory_settings_snapshot(
+        &manifest::WorkspaceMemorySettingsSnapshot {
+            workspace_id: record.workspace_id.clone(),
+            settings_revision: record.settings_revision,
+            language: record.language.clone(),
+        },
+        expected_workspace_id,
+    )
+}
+
+fn normalize_workspace_memory_language(language: &str) -> Result<String> {
+    let language = language.trim();
+    if !manifest::is_normalized_workspace_memory_language(language) {
+        return Err(Error::InvalidInput(format!(
+            "Workspace Memory language must be a non-empty UTF-8 string of at most {} characters without control characters",
+            manifest::MAX_WORKSPACE_MEMORY_LANGUAGE_CHARS
+        )));
+    }
+    Ok(language.to_string())
+}
+
+fn bound_worker_create_fingerprint(
+    request_fingerprint: &str,
+    snapshot: &manifest::WorkspaceMemorySettingsSnapshot,
+) -> String {
+    let mut digest = Sha256::new();
+    digest.update(b"workspace-worker-create-v2\0");
+    digest.update(request_fingerprint.as_bytes());
+    digest.update(b"\0");
+    digest.update(snapshot.workspace_id.as_bytes());
+    digest.update(b"\0");
+    digest.update(snapshot.settings_revision.to_be_bytes());
+    digest.update(b"\0");
+    digest.update(snapshot.language.as_bytes());
+    let encoded = digest
+        .finalize()
+        .iter()
+        .map(|byte| format!("{byte:02x}"))
+        .collect::<String>();
+    format!("sha256:{encoded}")
+}
+
 fn current_schema_version(conn: &Connection) -> Result<i64> {
     conn.query_row(
         "SELECT COALESCE(MAX(version), 0) FROM __yoi_schema_migrations",
@@ -6373,6 +6640,42 @@ fn add_workspace_resource_human_keys(conn: &Connection) -> Result<()> {
     Ok(())
 }
 
+fn create_workspace_memory_settings_authority(conn: &Connection) -> Result<()> {
+    conn.execute_batch(
+        r#"
+        CREATE TABLE workspace_memory_settings (
+            workspace_id TEXT PRIMARY KEY NOT NULL,
+            settings_revision INTEGER NOT NULL CHECK(settings_revision >= 1),
+            language TEXT NOT NULL CHECK(length(trim(language)) > 0),
+            created_at TEXT NOT NULL,
+            updated_at TEXT NOT NULL,
+            FOREIGN KEY (workspace_id) REFERENCES workspaces(workspace_id) ON DELETE CASCADE
+        );
+
+        INSERT INTO workspace_memory_settings (
+            workspace_id,
+            settings_revision,
+            language,
+            created_at,
+            updated_at
+        )
+        SELECT workspace_id, 1, 'English', created_at, updated_at
+        FROM workspaces;
+
+        ALTER TABLE worker_create_reservations
+            ADD COLUMN request_fingerprint TEXT;
+        ALTER TABLE worker_create_reservations
+            ADD COLUMN memory_settings_revision INTEGER;
+        ALTER TABLE worker_create_reservations
+            ADD COLUMN memory_language TEXT;
+
+        UPDATE worker_create_reservations
+        SET request_fingerprint = create_fingerprint;
+        "#,
+    )?;
+    Ok(())
+}
+
 fn verify_workspace_resource_key_schema(conn: &Connection) -> Result<()> {
     ticket::migrate_sqlite_ticket_resource_key_schema_in_transaction(conn).map_err(|error| {
         Error::Store(format!(
@@ -7682,7 +7985,7 @@ mod tests {
         let before = std::fs::read(&path).unwrap();
         let plan = SqliteWorkspaceStore::migration_plan(&path).unwrap();
         assert_eq!(plan.current_schema_version, 36);
-        assert_eq!(plan.target_schema_version, 41);
+        assert_eq!(plan.target_schema_version, 42);
         assert!(plan.migration_required);
         assert_eq!(plan.worker_count, 1);
         assert_eq!(plan.mappings[0].legacy_worker_id, 7);
@@ -7696,7 +7999,7 @@ mod tests {
         store
             .with_conn(|conn| {
                 assert!(table_exists(conn, "worker_diagnostics_archives")?);
-                assert_eq!(current_schema_version(conn)?, 41);
+                assert_eq!(current_schema_version(conn)?, 42);
                 Ok(())
             })
             .unwrap();
@@ -7775,7 +8078,7 @@ mod tests {
                 ),
             ]
         );
-        assert_eq!(current_schema_version(&conn).unwrap(), 41);
+        assert_eq!(current_schema_version(&conn).unwrap(), 42);
         let foreign_key_error: Option<String> = conn
             .query_row("PRAGMA foreign_key_check", [], |row| row.get(0))
             .optional()
@@ -7904,7 +8207,7 @@ INSERT INTO worker_orphan_diagnostics (
 
         apply_migrations(&conn).unwrap();
 
-        assert_eq!(current_schema_version(&conn).unwrap(), 41);
+        assert_eq!(current_schema_version(&conn).unwrap(), 42);
         assert!(!table_exists(&conn, "worker_control_delegation_operations").unwrap());
         let controller_worker_id: String = conn
             .query_row(
@@ -8022,10 +8325,36 @@ INSERT INTO worker_orphan_diagnostics (
 
         apply_migrations(&conn).unwrap();
 
-        assert_eq!(current_schema_version(&conn).unwrap(), 41);
+        assert_eq!(current_schema_version(&conn).unwrap(), 42);
         assert!(table_exists(&conn, "worker_workdir_attachment_reservations").unwrap());
     }
 
+    #[test]
+    fn schema_v42_initializes_existing_workspaces_with_explicit_english_memory_settings() {
+        let conn = Connection::open_in_memory().unwrap();
+        configure_sqlite(&conn).unwrap();
+        apply_migrations_through(&conn, 41).unwrap();
+        conn.execute(
+            "INSERT INTO workspaces (workspace_id, display_name, state, created_at, updated_at) \
+             VALUES ('workspace-existing', 'Existing', 'active', '1', '1')",
+            [],
+        )
+        .unwrap();
+
+        apply_migrations(&conn).unwrap();
+
+        assert_eq!(current_schema_version(&conn).unwrap(), 42);
+        let settings = conn
+            .query_row(
+                "SELECT settings_revision, language FROM workspace_memory_settings \
+                 WHERE workspace_id = 'workspace-existing'",
+                [],
+                |row| Ok((row.get::<_, i64>(0)?, row.get::<_, String>(1)?)),
+            )
+            .unwrap();
+        assert_eq!(settings, (1, "English".to_string()));
+    }
+
     #[test]
     fn schema_v26_removes_legacy_backend_flow_runtime_tables() {
         let conn = Connection::open_in_memory().unwrap();
@@ -8055,7 +8384,7 @@ CREATE TABLE flow_events (event_id TEXT PRIMARY KEY);
 
         apply_migrations(&conn).unwrap();
 
-        assert_eq!(current_schema_version(&conn).unwrap(), 41);
+        assert_eq!(current_schema_version(&conn).unwrap(), 42);
         assert!(table_exists(&conn, "flow_sources").unwrap());
         assert!(table_exists(&conn, "flow_source_revisions").unwrap());
         assert!(!table_exists(&conn, "flow_instances").unwrap());
@@ -8122,7 +8451,7 @@ INSERT INTO worker_workdir_attachment_reservations (
 
         apply_migrations(&conn).unwrap();
 
-        assert_eq!(current_schema_version(&conn).unwrap(), 41);
+        assert_eq!(current_schema_version(&conn).unwrap(), 42);
         let repositories_sql: String = conn
             .query_row(
                 "SELECT sql FROM sqlite_master WHERE type = 'table' AND name = 'repositories'",
@@ -8300,7 +8629,7 @@ INSERT INTO workdir_registry (
         let db = dir.path().join("control-plane.sqlite");
         let store = SqliteWorkspaceStore::open(&db).unwrap();
 
-        assert_eq!(store.schema_version().await.unwrap(), 41);
+        assert_eq!(store.schema_version().await.unwrap(), 42);
         assert!(
             !store
                 .with_conn(|conn| table_exists(conn, "worker_workspace_credentials"))
@@ -8317,7 +8646,7 @@ INSERT INTO workdir_registry (
         store.upsert_workspace(&record).await.unwrap();
 
         let reopened = SqliteWorkspaceStore::open(&db).unwrap();
-        assert_eq!(reopened.schema_version().await.unwrap(), 41);
+        assert_eq!(reopened.schema_version().await.unwrap(), 42);
         assert_eq!(
             reopened.get_workspace("local-dev").await.unwrap(),
             Some(record)
@@ -8386,22 +8715,54 @@ INSERT INTO workdir_registry (
             .await
             .unwrap();
 
+        let memory_settings = store.get_workspace_memory_settings("workspace-a").unwrap();
+        assert_eq!(memory_settings.settings_revision, 1);
+        assert_eq!(memory_settings.language, "English");
         let reserved = store
-            .reserve_worker_create("workspace-a", "arcadia", "operation-1", "sha256:one")
+            .reserve_worker_create(
+                "workspace-a",
+                "arcadia",
+                "operation-1",
+                "sha256:one",
+                &memory_settings,
+            )
             .unwrap();
         assert_eq!(
-            reserved.as_uuid().get_version(),
+            reserved.worker_id.as_uuid().get_version(),
             Some(uuid::Version::SortRand)
         );
+        assert_eq!(reserved.memory_settings.settings_revision, 1);
+        assert_eq!(reserved.memory_settings.language, "English");
+        let unchanged_memory_settings = store
+            .update_workspace_memory_settings("workspace-a", 1, " English ")
+            .unwrap();
+        assert_eq!(unchanged_memory_settings, memory_settings);
+        let updated_memory_settings = store
+            .update_workspace_memory_settings("workspace-a", 1, " Français ")
+            .unwrap();
+        assert_eq!(updated_memory_settings.settings_revision, 2);
+        assert_eq!(updated_memory_settings.language, "Français");
         assert_eq!(
             store
-                .reserve_worker_create("workspace-a", "arcadia", "operation-1", "sha256:one")
+                .reserve_worker_create(
+                    "workspace-a",
+                    "arcadia",
+                    "operation-1",
+                    "sha256:one",
+                    &updated_memory_settings,
+                )
                 .unwrap(),
             reserved
         );
         assert!(
             store
-                .reserve_worker_create("workspace-a", "arcadia", "operation-1", "sha256:different")
+                .reserve_worker_create(
+                    "workspace-a",
+                    "arcadia",
+                    "operation-1",
+                    "sha256:different",
+                    &updated_memory_settings,
+                )
                 .is_err()
         );
         assert_eq!(
@@ -8409,7 +8770,7 @@ INSERT INTO workdir_registry (
                 .resource_key(
                     "workspace-a",
                     WorkspaceResourceKind::Worker,
-                    &reserved.to_string()
+                    &reserved.worker_id.to_string()
                 )
                 .unwrap()
                 .as_deref(),
@@ -8419,37 +8780,85 @@ INSERT INTO workdir_registry (
             store
                 .resolve_resource_reference("workspace-a", WorkspaceResourceKind::Worker, "W-1")
                 .unwrap(),
-            Some(reserved.to_string())
+            Some(reserved.worker_id.to_string())
         );
         let second = store
-            .reserve_worker_create("workspace-a", "arcadia", "operation-2", "sha256:two")
+            .reserve_worker_create(
+                "workspace-a",
+                "arcadia",
+                "operation-2",
+                "sha256:two",
+                &updated_memory_settings,
+            )
             .unwrap();
+        assert_eq!(second.memory_settings.settings_revision, 2);
         assert_eq!(
             store
                 .resource_key(
                     "workspace-a",
                     WorkspaceResourceKind::Worker,
-                    &second.to_string()
+                    &second.worker_id.to_string()
                 )
                 .unwrap()
                 .as_deref(),
             Some("W-2")
         );
         store
-            .complete_worker_create_reservation("workspace-a", reserved)
+            .complete_worker_create_reservation("workspace-a", reserved.worker_id)
             .unwrap();
         let state: String = store
             .with_conn(|conn| {
                 conn.query_row(
                     "SELECT state FROM worker_create_reservations \
                      WHERE workspace_id = 'workspace-a' AND worker_id = ?1",
-                    [reserved.to_string()],
+                    [reserved.worker_id.to_string()],
                     |row| row.get(0),
                 )
                 .map_err(Error::from)
             })
             .unwrap();
         assert_eq!(state, "created");
+
+        store
+            .with_conn(|conn| {
+                conn.execute(
+                    "UPDATE workspace_memory_settings SET language = ' English ' \
+                     WHERE workspace_id = 'workspace-a'",
+                    [],
+                )?;
+                Ok(())
+            })
+            .unwrap();
+        assert!(store.get_workspace_memory_settings("workspace-a").is_err());
+        assert!(
+            store
+                .update_workspace_memory_settings("workspace-a", 2, "Spanish")
+                .is_err()
+        );
+        let mut corrupt = updated_memory_settings.clone();
+        corrupt.language = " English ".to_string();
+        assert!(
+            store
+                .reserve_worker_create(
+                    "workspace-a",
+                    "arcadia",
+                    "operation-corrupt",
+                    "sha256:corrupt",
+                    &corrupt,
+                )
+                .is_err()
+        );
+
+        store
+            .with_conn(|conn| {
+                conn.execute(
+                    "DELETE FROM workspace_memory_settings WHERE workspace_id = 'workspace-a'",
+                    [],
+                )?;
+                Ok(())
+            })
+            .unwrap();
+        assert!(store.get_workspace_memory_settings("workspace-a").is_err());
     }
 
     #[tokio::test]
@@ -8816,13 +9225,13 @@ INSERT INTO worker_registry (
         configure_sqlite(&conn).unwrap();
         apply_migrations(&conn).unwrap();
         conn.execute(
-            "INSERT INTO __yoi_schema_migrations (version, name) VALUES (42, 'future')",
+            "INSERT INTO __yoi_schema_migrations (version, name) VALUES (43, 'future')",
             [],
         )
         .unwrap();
 
         let error = apply_migrations(&conn).unwrap_err().to_string();
-        assert!(error.contains("schema version 42 is newer"), "{error}");
+        assert!(error.contains("schema version 43 is newer"), "{error}");
         assert!(error.contains("refusing to serve"), "{error}");
     }
 
@@ -9043,7 +9452,7 @@ VALUES ('workspace-b', 'ticket-b', 'related', 'ticket-a', NULL, 'tester', '2026-
 
         apply_migrations(&mut conn).unwrap();
 
-        assert_eq!(current_schema_version(&conn).unwrap(), 41);
+        assert_eq!(current_schema_version(&conn).unwrap(), 42);
         let workspace_id: Option<String> = conn
             .query_row(
                 "SELECT workspace_id FROM trusted_runtime_records WHERE runtime_id = 'runtime-a'",
@@ -9660,7 +10069,7 @@ WHERE workspace_id = 'workspace-a'
         .unwrap();
 
         let store = SqliteWorkspaceStore::from_connection(conn).unwrap();
-        assert_eq!(store.schema_version().await.unwrap(), 41);
+        assert_eq!(store.schema_version().await.unwrap(), 42);
 
         store
             .with_conn(|conn| {
@@ -9849,7 +10258,7 @@ CREATE TABLE ticket_assignment_operations (
     #[tokio::test]
     async fn repository_records_round_trip() {
         let store = SqliteWorkspaceStore::in_memory().unwrap();
-        assert_eq!(store.schema_version().await.unwrap(), 41);
+        assert_eq!(store.schema_version().await.unwrap(), 42);
         let workspace = WorkspaceRecord {
             workspace_id: "local-dev".to_string(),
             owner_account_id: None,
@@ -9915,7 +10324,7 @@ CREATE TABLE ticket_assignment_operations (
     #[tokio::test]
     async fn memory_authority_records_round_trip_and_close_staging() {
         let store = SqliteWorkspaceStore::in_memory().unwrap();
-        assert_eq!(store.schema_version().await.unwrap(), 41);
+        assert_eq!(store.schema_version().await.unwrap(), 42);
         let workspace = WorkspaceRecord {
             workspace_id: "local-dev".to_string(),
             owner_account_id: None,
@@ -10317,7 +10726,7 @@ CREATE TABLE ticket_assignment_operations (
     #[tokio::test]
     async fn account_and_login_records_round_trip() {
         let store = SqliteWorkspaceStore::in_memory().unwrap();
-        assert_eq!(store.schema_version().await.unwrap(), 41);
+        assert_eq!(store.schema_version().await.unwrap(), 42);
         let now = "2026-07-22T00:00:00Z".to_string();
         let account = AccountRecord {
             account_id: "acct-user-alice".to_string(),