diff --git a/src-tauri/Cargo.lock b/src-tauri/Cargo.lock
index 0987505b..f1aed8d7 100644
--- a/src-tauri/Cargo.lock
+++ b/src-tauri/Cargo.lock
@@ -6675,6 +6675,14 @@ dependencies = [
  "wasmparser",
 ]
 
+[[package]]
+name = "worldscript-project"
+version = "0.1.0"
+dependencies = [
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "worldscript-studio"
 version = "1.27.1"
@@ -6699,6 +6707,7 @@ dependencies = [
  "tauri-plugin-updater",
  "tauri-plugin-window-state",
  "tokio",
+ "worldscript-project",
 ]
 
 [[package]]
diff --git a/src-tauri/Cargo.toml b/src-tauri/Cargo.toml
index 5fed8d12..9b1820f3 100644
--- a/src-tauri/Cargo.toml
+++ b/src-tauri/Cargo.toml
@@ -40,6 +40,7 @@ tauri-plugin-process = "2"
 tokio = { version = "1", features = ["sync", "time", "process", "rt-multi-thread"] }
 candle-core = { version = "0.11", optional = true }
 candle-nn = { version = "0.11", optional = true }
+worldscript-project = { path = "../crates/worldscript-project" }
 
 [profile.release]
 # QNBS-v3: Aggressive size + speed optimizations for desktop bundles
diff --git a/src-tauri/src/commands/mod.rs b/src-tauri/src/commands/mod.rs
index 354e8041..02f2cdec 100644
--- a/src-tauri/src/commands/mod.rs
+++ b/src-tauri/src/commands/mod.rs
@@ -3,4 +3,5 @@
 //!          native-compute surface isolated from the flat top-level command files
 //!          (lora.rs / pandoc.rs) so the supervisor can grow its own task registry.
 
+pub mod project_core;
 pub mod task_supervisor;
diff --git a/src-tauri/src/commands/project_core.rs b/src-tauri/src/commands/project_core.rs
new file mode 100644
index 00000000..471e4352
--- /dev/null
+++ b/src-tauri/src/commands/project_core.rs
@@ -0,0 +1,138 @@
+//! Wave 2 PR B — strangler proof point: wires one real Tauri command to the renderer-neutral
+//! `worldscript-project` Rust Core crate (`docs/native/CORE-MIGRATION-LEDGER.md`).
+//!
+//! Backend-only. No frontend call site exists yet — `services/desktopPlatform.ts` and
+//! `services/fs/projectFsStore.ts`/`services/storageService.ts`'s dispatch are untouched by this
+//! PR. The point of this command is proving the Tauri <-> Rust Core boundary compiles, links, and
+//! runs correctly before any UI wiring is attempted.
+//!
+//! **Cannot yet validate a live persisted project as-is.** `worldscript_project::schema` models
+//! `characters`/`worlds` as plain arrays, not the `Character[] | EntityState<Character, string>`
+//! union `types.ts` uses (Redux normalizes to `EntityState` at runtime) — see that module's own
+//! doc comment. A real frontend caller will need a normalization adapter (array <-> EntityState)
+//! before this command can validate what's actually persisted; that adapter is intentionally not
+//! built here, matching this PR's no-frontend-call-site scope.
+
+use serde::Serialize;
+use worldscript_project::{migrate_to_latest, parse_envelope, validate};
+
+/// Structured verdict for a project envelope JSON string, mirroring the pipeline a future
+/// desktop load path would run: parse -> migrate to current schema -> validate.
+#[derive(Debug, Serialize, PartialEq)]
+#[serde(rename_all = "camelCase")]
+pub struct ProjectValidationResult {
+    pub valid: bool,
+    /// The schema version after migration, when parsing succeeded. Absent on parse failure.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub schema_version: Option<u32>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub error: Option<String>,
+}
+
+/// Parses, migrates, and validates a `ProjectEnvelope` JSON string via the `worldscript-project`
+/// crate. Never returns `Err` — parse/migrate/validate failures are reported as a structured
+/// `ProjectValidationResult { valid: false, error: Some(..) }`, matching the honest-failure
+/// convention `commands::task_supervisor` already established for this codebase.
+#[tauri::command]
+pub fn worldscript_project_validate(project_json: String) -> ProjectValidationResult {
+    let envelope = match parse_envelope(&project_json) {
+        Ok(envelope) => envelope,
+        Err(e) => {
+            return ProjectValidationResult {
+                valid: false,
+                schema_version: None,
+                error: Some(e.to_string()),
+            }
+        }
+    };
+
+    let migrated = match migrate_to_latest(envelope) {
+        Ok(migrated) => migrated,
+        Err(e) => {
+            return ProjectValidationResult {
+                valid: false,
+                schema_version: None,
+                error: Some(e.to_string()),
+            }
+        }
+    };
+
+    match validate(&migrated.project) {
+        Ok(()) => ProjectValidationResult {
+            valid: true,
+            schema_version: Some(migrated.schema_version),
+            error: None,
+        },
+        Err(e) => ProjectValidationResult {
+            valid: false,
+            schema_version: Some(migrated.schema_version),
+            error: Some(e.to_string()),
+        },
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn valid_current_schema_project_passes() {
+        let json = r#"{
+            "schemaVersion": 2,
+            "project": {
+                "title": "T", "logline": "L",
+                "characters": [], "worlds": [], "manuscript": []
+            }
+        }"#;
+        let result = worldscript_project_validate(json.to_string());
+        assert_eq!(
+            result,
+            ProjectValidationResult {
+                valid: true,
+                schema_version: Some(2),
+                error: None,
+            }
+        );
+    }
+
+    #[test]
+    fn v1_project_is_migrated_before_validation() {
+        let json = r#"{
+            "schemaVersion": 1,
+            "project": {
+                "title": "Old", "logline": "L",
+                "characters": [], "worlds": [], "manuscript": []
+            }
+        }"#;
+        let result = worldscript_project_validate(json.to_string());
+        assert!(result.valid);
+        assert_eq!(result.schema_version, Some(2));
+    }
+
+    #[test]
+    fn corrupt_json_reports_structured_failure_not_a_panic() {
+        let result = worldscript_project_validate("{ not json".to_string());
+        assert!(!result.valid);
+        assert_eq!(result.schema_version, None);
+        assert!(result.error.is_some());
+    }
+
+    #[test]
+    fn duplicate_character_ids_fail_validation_with_schema_version_present() {
+        let json = r#"{
+            "schemaVersion": 2,
+            "project": {
+                "title": "T", "logline": "L",
+                "characters": [
+                    {"id": "c1", "name": "A"},
+                    {"id": "c1", "name": "B"}
+                ],
+                "worlds": [], "manuscript": []
+            }
+        }"#;
+        let result = worldscript_project_validate(json.to_string());
+        assert!(!result.valid);
+        assert_eq!(result.schema_version, Some(2));
+        assert!(result.error.unwrap().contains("c1"));
+    }
+}
diff --git a/src-tauri/src/lib.rs b/src-tauri/src/lib.rs
index 1263cbe3..1a116d38 100644
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -166,6 +166,7 @@ pub fn run() {
             lora::set_lora_python_path,
             commands::task_supervisor::worldscript_task_supervisor_ping,
             commands::task_supervisor::worldscript_task_supervisor_submit,
+            commands::project_core::worldscript_project_validate,
         ])
         .setup(|app| {
             if cfg!(debug_assertions) {