diff --git a/sdk/typescript/src/api.ts b/sdk/typescript/src/api.ts
index cb90e089..b7a90921 100644
--- a/sdk/typescript/src/api.ts
+++ b/sdk/typescript/src/api.ts
@@ -637,15 +637,6 @@ export class CodexSecurity {
           `Shell-visible plugin root must be outside CODEX_HOME: ${canonicalShellPluginRoot}`,
         );
       }
-      const basePrompt = await scanPrompt(
-        shellPluginRoot,
-        normalized,
-        mode,
-        runtime.configPath !== undefined,
-        knowledgeBase !== null,
-        options.scanPrompt,
-      );
-      checkOpen();
       const expectation: ScanExpectation = {
         repository: repo,
         repositoryRevision: await (
@@ -840,6 +831,16 @@ export class CodexSecurity {
       }
       activeScan = { id: scanId, options: workbenchOptions };
       checkOpen();
+      const basePrompt = await scanPrompt(
+        shellPluginRoot,
+        normalized,
+        mode,
+        scanId,
+        runtime.configPath !== undefined,
+        knowledgeBase !== null,
+        options.scanPrompt,
+      );
+      checkOpen();
       const feedback = await workbench(
         {
           ...workbenchOptions,
@@ -2023,6 +2024,7 @@ async function scanPrompt(
   pluginRoot: string,
   target: NormalizedTarget,
   mode: ScanMode,
+  scanId: string,
   hasConfigPath = false,
   hasKnowledgeBase = false,
   additionalPrompt?: string,
@@ -2040,11 +2042,11 @@ async function scanPrompt(
     "Run this Codex Security scan non-interactively.",
     ...(mode === "deep"
       ? [
-          'The SDK has already registered this scan. Call start_codex_security_deep_scan with { scanId: "$CODEX_SECURITY_SCAN_ID" }; never pass targetPath or create another scan.',
+          `The SDK has already registered this scan. Call start_codex_security_deep_scan with { scanId: ${JSON.stringify(scanId)} }; never pass targetPath or create another scan.`,
         ]
       : skillName === "security-scan"
         ? [
-            'The SDK has already registered this scan. Use exactly "$CODEX_SECURITY_SCAN_ID" and "$CODEX_SECURITY_SCAN_DIR"; never call a scan-start or completion tool, and leave finalization to the SDK.',
+            `The SDK has already registered this scan. Use exactly ${JSON.stringify(scanId)} and "$CODEX_SECURITY_SCAN_DIR"; never call a scan-start or completion tool, and leave finalization to the SDK.`,
           ]
         : []),
     ...(skillName === "security-scan"
@@ -2060,7 +2062,7 @@ async function scanPrompt(
     'Use "$PYTHON" as <python_command> for every plugin helper; replace any literal python or python3 helper invocation with this exact interpreter.',
     'Repository root: "$CODEX_SECURITY_REPOSITORY"',
     'Use this exact scan directory for all scan output: "$CODEX_SECURITY_SCAN_DIR"',
-    'Use exactly "$CODEX_SECURITY_SCAN_ID" as the scan ID in the manifest, findings, and coverage.',
+    `Use exactly ${JSON.stringify(scanId)} as the scan ID in the manifest, findings, and coverage.`,
     'Use exactly "$CODEX_SECURITY_TARGET_ID" as scan.target.targetId; do not derive a different target ID.',
     'Use exactly "$CODEX_SECURITY_TARGET_DISPLAY_NAME" as scan.target.displayName; do not infer a display name from the Git remote.',
     'Use exactly "$CODEX_SECURITY_TARGET_KIND" as scan.target.kind; do not infer the target kind from the checkout.',
diff --git a/sdk/typescript/tests-ts/api.test.ts b/sdk/typescript/tests-ts/api.test.ts
index ec8076ae..98d5aa32 100644
--- a/sdk/typescript/tests-ts/api.test.ts
+++ b/sdk/typescript/tests-ts/api.test.ts
@@ -2632,6 +2632,77 @@ describe("CodexSecurity orchestration", () => {
     await client.close();
   });
 
+  test("uses the registered scan ID in standard and deep prompts", async () => {
+    const scanId = "123e4567-e89b-12d3-a456-426614174000";
+
+    for (const mode of ["standard", "deep"] as const) {
+      for (const withFeedback of [false, true]) {
+        const root = await temporaryDirectory();
+        const repository = join(root, "repository");
+        const codexHome = join(root, "codex-home");
+        const scanDir = join(root, "scan");
+        await mkdir(repository);
+        await mkdir(codexHome);
+        await mkdir(scanDir, { mode: 0o700 });
+        let prompt = "";
+        const client = new TestClient(
+          {},
+          {
+            environment: {},
+            prepareRuntime: async () => preparedRuntime(codexHome),
+            resolvePluginPython: async () => "/managed/python",
+            prepareOutputDir: async () => scanDir,
+            repositoryRevision: async () => "deadbeef",
+            runWorkbench: async (
+              _options: unknown,
+              args: readonly string[],
+            ) => {
+              if (args[0] === "register-cli-scan") {
+                return { ...mockScanRegistration(args), scanId };
+              }
+              if (args[0] === "get-scan-feedback") {
+                return {
+                  scanId,
+                  targetId: "target_sha256_example",
+                  falsePositives: withFeedback
+                    ? [{ reason: "The finding is no longer reproducible." }]
+                    : [],
+                };
+              }
+              return {};
+            },
+            createCodex: () => ({
+              startThread: () => ({
+                id: null,
+                async runStreamed(input: string) {
+                  prompt = input;
+                  throw new Error("prompt captured");
+                },
+              }),
+            }),
+          },
+        );
+
+        await expect(client.run(repository, { mode })).rejects.toThrow(
+          "prompt captured",
+        );
+        expect(prompt).toContain(
+          `Use exactly "${scanId}" as the scan ID in the manifest, findings, and coverage.`,
+        );
+        expect(prompt).not.toContain("$CODEX_SECURITY_SCAN_ID");
+        if (mode === "deep") {
+          expect(prompt).toContain(
+            `start_codex_security_deep_scan with { scanId: "${scanId}" }`,
+          );
+        }
+        if (withFeedback) {
+          expect(prompt).toContain("false_positive_feedback.json");
+        }
+        await client.close();
+      }
+    }
+  });
+
   test("rejects feedback from another scan or invalid reviewer feedback", async () => {
     const scanId = "scan_example_001";
     const targetId = "target_sha256_example";
@@ -4319,7 +4390,7 @@ describe("CodexSecurity orchestration", () => {
     );
     expect(prompt).toContain("$codex-security:deep-security-scan");
     expect(prompt).toContain(
-      'start_codex_security_deep_scan with { scanId: "$CODEX_SECURITY_SCAN_ID" }',
+      'start_codex_security_deep_scan with { scanId: "scan_example_001" }',
     );
     expect(prompt).not.toContain(
       "This exhaustive scan authorizes the delegated-worker phases",