diff --git a/agent/model_metadata.py b/agent/model_metadata.py
index 3dc3e9e13..758ca0520 100644
--- a/agent/model_metadata.py
+++ b/agent/model_metadata.py
@@ -69,15 +69,15 @@ CONTEXT_PROBE_TIERS = [
 DEFAULT_CONTEXT_LENGTHS = {
     "anthropic/claude-opus-4": 200000,
     "anthropic/claude-opus-4.5": 200000,
-    "anthropic/claude-opus-4.6": 200000,
+    "anthropic/claude-opus-4.6": 1000000,
     "anthropic/claude-sonnet-4": 200000,
     "anthropic/claude-sonnet-4-20250514": 200000,
     "anthropic/claude-sonnet-4.5": 200000,
-    "anthropic/claude-sonnet-4.6": 200000,
+    "anthropic/claude-sonnet-4.6": 1000000,
     "anthropic/claude-haiku-4.5": 200000,
     # Bare Anthropic model IDs (for native API provider)
-    "claude-opus-4-6": 200000,
-    "claude-sonnet-4-6": 200000,
+    "claude-opus-4-6": 1000000,
+    "claude-sonnet-4-6": 1000000,
     "claude-opus-4-5-20251101": 200000,
     "claude-sonnet-4-5-20250929": 200000,
     "claude-opus-4-1-20250805": 200000,
diff --git a/tests/agent/test_model_metadata.py b/tests/agent/test_model_metadata.py
index 75770ce31..dba8f6e13 100644
--- a/tests/agent/test_model_metadata.py
+++ b/tests/agent/test_model_metadata.py
@@ -106,9 +106,14 @@ class TestEstimateMessagesTokensRough:
 # =========================================================================
 
 class TestDefaultContextLengths:
-    def test_claude_models_200k(self):
+    def test_claude_models_context_lengths(self):
         for key, value in DEFAULT_CONTEXT_LENGTHS.items():
-            if "claude" in key:
+            if "claude" not in key:
+                continue
+            # Claude 4.6 models have 1M context
+            if "4.6" in key or "4-6" in key:
+                assert value == 1000000, f"{key} should be 1000000"
+            else:
                 assert value == 200000, f"{key} should be 200000"
 
     def test_gpt4_models_128k_or_1m(self):