diff --git a/.changeset/fix-anthropic-profile-undefined-model.md b/.changeset/fix-anthropic-profile-undefined-model.md
new file mode 100644
index 0000000000..5db03cac00
--- /dev/null
+++ b/.changeset/fix-anthropic-profile-undefined-model.md
@@ -0,0 +1,5 @@
+---
+"@moonshot-ai/kosong": patch
+---
+
+Fix a crash when a model config entry lacks the `model` field (e.g. from a malformed TOML key like `[models.kimi-k2.7-code]`): the Anthropic profile matchers now tolerate `undefined` model names and return no profile instead of throwing `TypeError: Cannot read properties of undefined (reading 'toLowerCase')`.
diff --git a/packages/kosong/src/providers/anthropic-profile.ts b/packages/kosong/src/providers/anthropic-profile.ts
index b5d05934ea..c2c61a3f1a 100644
--- a/packages/kosong/src/providers/anthropic-profile.ts
+++ b/packages/kosong/src/providers/anthropic-profile.ts
@@ -74,9 +74,10 @@ const VERSION_FIRST_RE = /(\d{1,2})[-._](\d{1,2})[-._](opus|sonnet|haiku)/;
 const BARE_FAMILY_RE = /(\d{1,2})[-._](opus|sonnet|haiku)/;
 
 export function parseAnthropicModelVersion(
-  model: string,
+  model: string | undefined,
   requireClaudeMarker = false,
 ): AnthropicModelVersion | null {
+  if (model === undefined) return null;
   const normalized = model.toLowerCase();
   if (requireClaudeMarker && !normalized.includes('claude')) return null;
 
@@ -111,8 +112,9 @@ export function parseAnthropicModelVersion(
 }
 
 export function matchKnownAnthropicModelProfile(
-  model: string,
+  model: string | undefined,
 ): AnthropicModelProfile | undefined {
+  if (model === undefined) return undefined;
   const normalized = model.toLowerCase();
   if (/mythos[-._]preview/.test(normalized)) return ALWAYS_ADAPTIVE_MAX_PROFILE;
 
@@ -164,7 +166,10 @@ export function inferAnthropicModelProfile(model: string): AnthropicModelProfile
  * fallback: an Anthropic-protocol endpoint still needs some profile to shape
  * requests.
  */
-export function matchUnknownClaudeProfile(model: string): AnthropicModelProfile | undefined {
+export function matchUnknownClaudeProfile(
+  model: string | undefined,
+): AnthropicModelProfile | undefined {
+  if (model === undefined) return undefined;
   const normalized = model.toLowerCase();
   return normalized.includes('claude') || CLAUDE_FAMILY_WORD_RE.test(normalized)
     ? LATEST_OPUS_PROFILE
diff --git a/packages/kosong/test/anthropic.test.ts b/packages/kosong/test/anthropic.test.ts
index 6b079a75a6..75e8941c12 100644
--- a/packages/kosong/test/anthropic.test.ts
+++ b/packages/kosong/test/anthropic.test.ts
@@ -98,6 +98,16 @@ describe('Anthropic model profile matching', () => {
       expect(matchUnknownClaudeProfile(model)).toBeUndefined();
     },
   );
+
+  // A malformed config entry (e.g. an unquoted dotted TOML key like
+  // `[models.kimi-k2.7-code]`) parses into a nested object that lacks the
+  // top-level `model` field. The v2 config schema marks `model` optional, so
+  // the entry reaches profile matching with `undefined` — the matcher must
+  // degrade to "no profile" instead of crashing the whole getModels call.
+  it('tolerates an undefined model name from a malformed config entry', () => {
+    expect(matchKnownAnthropicModelProfile(undefined as unknown as string)).toBeUndefined();
+    expect(matchUnknownClaudeProfile(undefined as unknown as string)).toBeUndefined();
+  });
 });
 
 type AnthropicGenerationState = {