diff --git a/src/renderer/src/pages/home/Inputbar/AgentSessionInputbar.tsx b/src/renderer/src/pages/home/Inputbar/AgentSessionInputbar.tsx
index 850be7f727..2aedab0b21 100644
--- a/src/renderer/src/pages/home/Inputbar/AgentSessionInputbar.tsx
+++ b/src/renderer/src/pages/home/Inputbar/AgentSessionInputbar.tsx
@@ -23,6 +23,7 @@ import { abortCompletion } from '@renderer/utils/abortController'
 import { buildAgentSessionTopicId } from '@renderer/utils/agentSession'
 import { getSendMessageShortcutLabel } from '@renderer/utils/input'
 import { createMainTextBlock, createMessage } from '@renderer/utils/messageUtils/create'
+import { parseModelId } from '@renderer/utils/model'
 import { documentExts, imageExts, textExts } from '@shared/config/constant'
 import type { FC } from 'react'
 import React, { useCallback, useEffect, useMemo, useRef } from 'react'
@@ -67,8 +68,9 @@ const AgentSessionInputbar: FC<Props> = ({ agentId, sessionId }) => {
     if (!session) return null
 
     // Extract model info
-    const [providerId, actualModelId] = session.model?.split(':') ?? [undefined, undefined]
-    const actualModel = actualModelId ? getModel(actualModelId, providerId) : undefined
+    // Use parseModelId to handle model IDs with colons (e.g., "openrouter:anthropic/claude:free")
+    const parsed = parseModelId(session.model)
+    const actualModel = parsed ? getModel(parsed.modelId, parsed.providerId) : undefined
 
     const model: Model | undefined = actualModel
       ? {
diff --git a/src/renderer/src/utils/__tests__/model.test.ts b/src/renderer/src/utils/__tests__/model.test.ts
index fe1697e3ed..79f7948fb1 100644
--- a/src/renderer/src/utils/__tests__/model.test.ts
+++ b/src/renderer/src/utils/__tests__/model.test.ts
@@ -1,7 +1,7 @@
 import type { Model, ModelTag } from '@renderer/types'
 import { describe, expect, it, vi } from 'vitest'
 
-import { getModelTags, isFreeModel } from '../model'
+import { getModelTags, isFreeModel, parseModelId } from '../model'
 
 // Mock the model checking functions from @renderer/config/models
 vi.mock('@renderer/config/models', () => ({
@@ -92,4 +92,56 @@ describe('model', () => {
       expect(getModelTags(models_2)).toStrictEqual(expected_2)
     })
   })
+
+  describe('parseModelId', () => {
+    it('should parse model identifiers with single colon', () => {
+      expect(parseModelId('anthropic:claude-3-sonnet')).toEqual({
+        providerId: 'anthropic',
+        modelId: 'claude-3-sonnet'
+      })
+
+      expect(parseModelId('openai:gpt-4')).toEqual({
+        providerId: 'openai',
+        modelId: 'gpt-4'
+      })
+    })
+
+    it('should parse model identifiers with multiple colons', () => {
+      expect(parseModelId('openrouter:anthropic/claude-3.5-sonnet:free')).toEqual({
+        providerId: 'openrouter',
+        modelId: 'anthropic/claude-3.5-sonnet:free'
+      })
+
+      expect(parseModelId('provider:model:suffix:extra')).toEqual({
+        providerId: 'provider',
+        modelId: 'model:suffix:extra'
+      })
+    })
+
+    it('should return undefined for invalid inputs', () => {
+      expect(parseModelId(undefined)).toBeUndefined()
+      expect(parseModelId('')).toBeUndefined()
+      expect(parseModelId('no-colon')).toBeUndefined()
+      expect(parseModelId(':missing-provider')).toBeUndefined()
+      expect(parseModelId('missing-model:')).toBeUndefined()
+      expect(parseModelId(':')).toBeUndefined()
+    })
+
+    it('should handle edge cases', () => {
+      expect(parseModelId('a:b')).toEqual({
+        providerId: 'a',
+        modelId: 'b'
+      })
+
+      expect(parseModelId('provider:model-with-dashes')).toEqual({
+        providerId: 'provider',
+        modelId: 'model-with-dashes'
+      })
+
+      expect(parseModelId('provider:model/with/slashes')).toEqual({
+        providerId: 'provider',
+        modelId: 'model/with/slashes'
+      })
+    })
+  })
 })
diff --git a/src/renderer/src/utils/model.ts b/src/renderer/src/utils/model.ts
index a74ffab25f..23e955eff3 100644
--- a/src/renderer/src/utils/model.ts
+++ b/src/renderer/src/utils/model.ts
@@ -81,3 +81,39 @@ export const apiModelAdapter = (model: ApiModel): AdaptedApiModel => {
     origin: model
   }
 }
+
+/**
+ * Parse a model identifier in the format "provider:modelId"
+ * where modelId may contain additional colons (e.g., "openrouter:anthropic/claude-3.5-sonnet:free")
+ *
+ * @param modelIdentifier - The full model identifier string
+ * @returns Object with providerId and modelId, or undefined if invalid
+ *
+ * @example
+ * parseModelId("openrouter:anthropic/claude-3.5-sonnet:free")
+ * // => { providerId: "openrouter", modelId: "anthropic/claude-3.5-sonnet:free" }
+ *
+ * @example
+ * parseModelId("anthropic:claude-3-sonnet")
+ * // => { providerId: "anthropic", modelId: "claude-3-sonnet" }
+ *
+ * @example
+ * parseModelId("invalid") // => undefined
+ */
+export function parseModelId(modelIdentifier: string | undefined): { providerId: string; modelId: string } | undefined {
+  if (!modelIdentifier || typeof modelIdentifier !== 'string') {
+    return undefined
+  }
+
+  const colonIndex = modelIdentifier.indexOf(':')
+
+  // Must contain at least one colon and have content on both sides
+  if (colonIndex <= 0 || colonIndex >= modelIdentifier.length - 1) {
+    return undefined
+  }
+
+  return {
+    providerId: modelIdentifier.substring(0, colonIndex),
+    modelId: modelIdentifier.substring(colonIndex + 1)
+  }
+}