diff --git a/packages/core/src/context/contextManager.ts b/packages/core/src/context/contextManager.ts
index 25cec4d93c..ca3115d4ec 100644
--- a/packages/core/src/context/contextManager.ts
+++ b/packages/core/src/context/contextManager.ts
@@ -139,7 +139,11 @@ export class ContextManager {
         this.hasPerformedHotStart = true;
         if (this.buffer.nodes.length > 0) {
           const nodesForHotStart = [...this.buffer.nodes, ...previewNodes];
-          await this.performHotStartCalibration(nodesForHotStart, abortSignal);
+          await this.performHotStartCalibration(
+            nodesForHotStart,
+            this.env.model,
+            abortSignal,
+          );
         }
       }
     })();
@@ -468,6 +472,7 @@ export class ContextManager {
 
   private async performHotStartCalibration(
     nodes: readonly ConcreteNode[],
+    model: string,
     abortSignal?: AbortSignal,
   ) {
     const history = this.env.graphMapper.fromGraph(nodes);
@@ -475,7 +480,7 @@ export class ContextManager {
 
     try {
       const { totalTokens } = await this.env.llmClient.countTokens({
-        modelConfigKey: { model: 'context-calibrator' },
+        modelConfigKey: { model },
         contents,
         abortSignal,
       });
diff --git a/packages/core/src/context/initializer.ts b/packages/core/src/context/initializer.ts
index dc19c127e1..0804f06509 100644
--- a/packages/core/src/context/initializer.ts
+++ b/packages/core/src/context/initializer.ts
@@ -116,6 +116,7 @@ export async function initializeContextManager(
 
   const env = new ContextEnvironmentImpl(
     () => config.getBaseLlmClient(),
+    () => config.getActiveModel(),
     config.getSessionId(),
     lastPromptId,
     logDir,
diff --git a/packages/core/src/context/pipeline/environment.ts b/packages/core/src/context/pipeline/environment.ts
index b57466638a..df4f2b6887 100644
--- a/packages/core/src/context/pipeline/environment.ts
+++ b/packages/core/src/context/pipeline/environment.ts
@@ -19,6 +19,7 @@ export interface RenderOptions {
 
 export interface ContextEnvironment {
   readonly llmClient: BaseLlmClient;
+  readonly model: string;
   readonly promptId: string;
   readonly sessionId: string;
   readonly traceDir: string;
diff --git a/packages/core/src/context/pipeline/environmentImpl.test.ts b/packages/core/src/context/pipeline/environmentImpl.test.ts
index d6f2835b89..7f52f1217b 100644
--- a/packages/core/src/context/pipeline/environmentImpl.test.ts
+++ b/packages/core/src/context/pipeline/environmentImpl.test.ts
@@ -21,6 +21,7 @@ describe('ContextEnvironmentImpl', () => {
 
     const env = new ContextEnvironmentImpl(
       () => mockLlmClient,
+      () => 'mock-model',
       'mock-session',
       'mock-prompt',
       '/tmp/trace',
diff --git a/packages/core/src/context/pipeline/environmentImpl.ts b/packages/core/src/context/pipeline/environmentImpl.ts
index 78f1b3dda5..405448807b 100644
--- a/packages/core/src/context/pipeline/environmentImpl.ts
+++ b/packages/core/src/context/pipeline/environmentImpl.ts
@@ -19,6 +19,7 @@ export class ContextEnvironmentImpl implements ContextEnvironment {
 
   constructor(
     private readonly llmClientProvider: () => BaseLlmClient,
+    private readonly activeModel: () => string,
     readonly sessionId: string,
     readonly promptId: string,
     readonly traceDir: string,
@@ -37,4 +38,8 @@ export class ContextEnvironmentImpl implements ContextEnvironment {
   get llmClient(): BaseLlmClient {
     return this.llmClientProvider();
   }
+
+  get model(): string {
+    return this.activeModel();
+  }
 }
diff --git a/packages/core/src/context/system-tests/simulationHarness.ts b/packages/core/src/context/system-tests/simulationHarness.ts
index f177b6ec7b..8f0d1290ea 100644
--- a/packages/core/src/context/system-tests/simulationHarness.ts
+++ b/packages/core/src/context/system-tests/simulationHarness.ts
@@ -68,6 +68,7 @@ export class SimulationHarness {
 
     this.env = new ContextEnvironmentImpl(
       () => mockLlmClient,
+      () => 'mock-model',
       'sim-prompt',
       'sim-session',
       mockTempDir,
diff --git a/packages/core/src/context/testing/contextTestUtils.ts b/packages/core/src/context/testing/contextTestUtils.ts
index fed08e2a82..389e33df52 100644
--- a/packages/core/src/context/testing/contextTestUtils.ts
+++ b/packages/core/src/context/testing/contextTestUtils.ts
@@ -181,7 +181,8 @@ export function createMockEnvironment(
 
   let env = new ContextEnvironmentImpl(
     () => llmClient as BaseLlmClient,
-    'mock-session',
+    () => 'mock-session',
+    'mock-model',
     'mock-prompt-id',
     '/tmp/.gemini/trace',
     '/tmp/.gemini/tool-outputs',
@@ -196,6 +197,7 @@ export function createMockEnvironment(
     if (overrides.llmClient) {
       env = new ContextEnvironmentImpl(
         () => overrides.llmClient!,
+        () => overrides.model!,
         env.sessionId,
         env.promptId,
         env.traceDir,
@@ -276,6 +278,7 @@ export function createMockContextConfig(
     getTargetDir: vi.fn().mockReturnValue('/tmp'),
     getSessionId: vi.fn().mockReturnValue('test-session'),
     getExperimentalContextManagementConfig: vi.fn().mockReturnValue(undefined),
+    getActiveModel: vi.fn().mockReturnValue('mock-model'),
   };
 
   // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
@@ -303,6 +306,7 @@ export function setupContextComponentTest(
 
   const env = new ContextEnvironmentImpl(
     () => config.getBaseLlmClient(),
+    () => config.getActiveModel(),
     'test prompt-id',
     'test-session',
     '/tmp',