feat: eliminate Azure OpenAI API version duplication

- Add URL parsing utility to extract API version from Base URL
- Modify OpenAI provider to use extracted API version when azureApiVersion field is not set
- Update UI to show helpful message when API version is detected in URL
- Add comprehensive tests for URL parsing functionality

Fixes #5805

src/api/providers/openai.ts

@@ -13,6 +13,7 @@ import {
 import type { ApiHandlerOptions } from "../../shared/api"
 
 import { XmlMatcher } from "../../utils/xml-matcher"
+import { extractApiVersionFromUrl, isAzureOpenAiUrl, removeApiVersionFromUrl } from "../../utils/azure-url-parser"
 
 import { convertToOpenAiMessages } from "../transform/openai-format"
 import { convertToR1Format } from "../transform/r1-format"
@@ -35,12 +36,25 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 		super()
 		this.options = options
 
-		const baseURL = this.options.openAiBaseUrl ?? "https://api.openai.com/v1"
+		const originalBaseURL = this.options.openAiBaseUrl ?? "https://api.openai.com/v1"
 		const apiKey = this.options.openAiApiKey ?? "not-provided"
 		const isAzureAiInference = this._isAzureAiInference(this.options.openAiBaseUrl)
 		const urlHost = this._getUrlHost(this.options.openAiBaseUrl)
 		const isAzureOpenAi = urlHost === "azure.com" || urlHost.endsWith(".azure.com") || options.openAiUseAzure
 
+		// Extract API version from URL if present and no explicit azureApiVersion is set
+		let effectiveApiVersion = this.options.azureApiVersion
+		let baseURL = originalBaseURL
+
+		if (isAzureOpenAi && !effectiveApiVersion) {
+			const extractedVersion = extractApiVersionFromUrl(originalBaseURL)
+			if (extractedVersion) {
+				effectiveApiVersion = extractedVersion
+				// For AzureOpenAI client, remove api-version from baseURL since it's passed separately
+				baseURL = removeApiVersionFromUrl(originalBaseURL)
+			}
+		}
+
 		const headers = {
 			...DEFAULT_HEADERS,
 			...(this.options.openAiHeaders || {}),
@@ -49,10 +63,10 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 		if (isAzureAiInference) {
 			// Azure AI Inference Service (e.g., for DeepSeek) uses a different path structure
 			this.client = new OpenAI({
-				baseURL,
+				baseURL: originalBaseURL, // Keep original URL for AI Inference
 				apiKey,
 				defaultHeaders: headers,
-				defaultQuery: { "api-version": this.options.azureApiVersion || "2024-05-01-preview" },
+				defaultQuery: { "api-version": effectiveApiVersion || "2024-05-01-preview" },
 			})
 		} else if (isAzureOpenAi) {
 			// Azure API shape slightly differs from the core API shape:
@@ -60,12 +74,12 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 			this.client = new AzureOpenAI({
 				baseURL,
 				apiKey,
-				apiVersion: this.options.azureApiVersion || azureOpenAiDefaultApiVersion,
+				apiVersion: effectiveApiVersion || azureOpenAiDefaultApiVersion,
 				defaultHeaders: headers,
 			})
 		} else {
 			this.client = new OpenAI({
-				baseURL,
+				baseURL: originalBaseURL,
 				apiKey,
 				defaultHeaders: headers,
 			})

src/utils/__tests__/azure-url-parser.test.ts

@@ -0,0 +1,124 @@
+import { describe, it, expect } from 'vitest'
+import { extractApiVersionFromUrl, isAzureOpenAiUrl, removeApiVersionFromUrl } from '../azure-url-parser'
+
+describe('azure-url-parser', () => {
+	describe('extractApiVersionFromUrl', () => {
+		it('should extract API version from Azure OpenAI URL', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions?api-version=2024-05-01-preview'
+			const result = extractApiVersionFromUrl(url)
+			expect(result).toBe('2024-05-01-preview')
+		})
+
+		it('should extract API version from URL with multiple query parameters', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions?foo=bar&api-version=2024-12-01-preview&baz=qux'
+			const result = extractApiVersionFromUrl(url)
+			expect(result).toBe('2024-12-01-preview')
+		})
+
+		it('should return null when no api-version parameter exists', () => {
+			const url = 'https://api.openai.com/v1/chat/completions'
+			const result = extractApiVersionFromUrl(url)
+			expect(result).toBeNull()
+		})
+
+		it('should return null for invalid URLs', () => {
+			const invalidUrl = 'not-a-valid-url'
+			const result = extractApiVersionFromUrl(invalidUrl)
+			expect(result).toBeNull()
+		})
+
+		it('should handle empty api-version parameter', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions?api-version='
+			const result = extractApiVersionFromUrl(url)
+			expect(result).toBe('')
+		})
+
+		it('should handle URL without query parameters', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions'
+			const result = extractApiVersionFromUrl(url)
+			expect(result).toBeNull()
+		})
+	})
+
+	describe('isAzureOpenAiUrl', () => {
+		it('should return true for Azure OpenAI URLs with .openai.azure.com', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions'
+			const result = isAzureOpenAiUrl(url)
+			expect(result).toBe(true)
+		})
+
+		it('should return true for Azure URLs ending with .azure.com', () => {
+			const url = 'https://myservice.azure.com/api/v1'
+			const result = isAzureOpenAiUrl(url)
+			expect(result).toBe(true)
+		})
+
+		it('should return true for URLs with /openai/deployments/ path', () => {
+			const url = 'https://custom-domain.com/openai/deployments/mymodel/chat/completions'
+			const result = isAzureOpenAiUrl(url)
+			expect(result).toBe(true)
+		})
+
+		it('should return false for regular OpenAI URLs', () => {
+			const url = 'https://api.openai.com/v1/chat/completions'
+			const result = isAzureOpenAiUrl(url)
+			expect(result).toBe(false)
+		})
+
+		it('should return false for other API URLs', () => {
+			const url = 'https://api.anthropic.com/v1/messages'
+			const result = isAzureOpenAiUrl(url)
+			expect(result).toBe(false)
+		})
+
+		it('should return false for invalid URLs', () => {
+			const invalidUrl = 'not-a-valid-url'
+			const result = isAzureOpenAiUrl(invalidUrl)
+			expect(result).toBe(false)
+		})
+
+		it('should handle case insensitive hostname matching', () => {
+			const url = 'https://MYRESOURCE.OPENAI.AZURE.COM/openai/deployments/mymodel'
+			const result = isAzureOpenAiUrl(url)
+			expect(result).toBe(true)
+		})
+	})
+
+	describe('removeApiVersionFromUrl', () => {
+		it('should remove api-version parameter from URL', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions?api-version=2024-05-01-preview'
+			const result = removeApiVersionFromUrl(url)
+			expect(result).toBe('https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions')
+		})
+
+		it('should remove api-version parameter while preserving other parameters', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions?foo=bar&api-version=2024-05-01-preview&baz=qux'
+			const result = removeApiVersionFromUrl(url)
+			expect(result).toBe('https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions?foo=bar&baz=qux')
+		})
+
+		it('should return original URL when no api-version parameter exists', () => {
+			const url = 'https://api.openai.com/v1/chat/completions?foo=bar'
+			const result = removeApiVersionFromUrl(url)
+			expect(result).toBe(url)
+		})
+
+		it('should return original URL for invalid URLs', () => {
+			const invalidUrl = 'not-a-valid-url'
+			const result = removeApiVersionFromUrl(invalidUrl)
+			expect(result).toBe(invalidUrl)
+		})
+
+		it('should handle URL with only api-version parameter', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions?api-version=2024-05-01-preview'
+			const result = removeApiVersionFromUrl(url)
+			expect(result).toBe('https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions')
+		})
+
+		it('should handle URL without query parameters', () => {
+			const url = 'https://myresource.openai.azure.com/openai/deployments/mymodel/chat/completions'
+			const result = removeApiVersionFromUrl(url)
+			expect(result).toBe(url)
+		})
+	})
+})

src/utils/azure-url-parser.ts

@@ -0,0 +1,53 @@
+/**
+ * Utility functions for parsing Azure OpenAI URLs and extracting API versions
+ */
+
+/**
+ * Extracts the API version from an Azure OpenAI URL query parameter
+ * @param url The Azure OpenAI URL that may contain an api-version query parameter
+ * @returns The extracted API version string, or null if not found
+ */
+export function extractApiVersionFromUrl(url: string): string | null {
+	try {
+		const urlObj = new URL(url)
+		return urlObj.searchParams.get('api-version')
+	} catch (error) {
+		// Invalid URL format
+		return null
+	}
+}
+
+/**
+ * Checks if a URL appears to be an Azure OpenAI URL
+ * @param url The URL to check
+ * @returns True if the URL appears to be an Azure OpenAI URL
+ */
+export function isAzureOpenAiUrl(url: string): boolean {
+	try {
+		const urlObj = new URL(url)
+		const host = urlObj.host.toLowerCase()
+		
+		// Check for Azure OpenAI hostname patterns
+		return host.includes('.openai.azure.com') || 
+		       host.endsWith('.azure.com') ||
+		       urlObj.pathname.includes('/openai/deployments/')
+	} catch (error) {
+		return false
+	}
+}
+
+/**
+ * Removes the api-version query parameter from a URL
+ * @param url The URL to clean
+ * @returns The URL without the api-version parameter
+ */
+export function removeApiVersionFromUrl(url: string): string {
+	try {
+		const urlObj = new URL(url)
+		urlObj.searchParams.delete('api-version')
+		return urlObj.toString()
+	} catch (error) {
+		// Return original URL if parsing fails
+		return url
+	}
+}

webview-ui/src/components/settings/providers/OpenAICompatible.tsx

@@ -12,6 +12,8 @@ import {
 	openAiModelInfoSaneDefaults,
 } from "@roo-code/types"
 
+import { extractApiVersionFromUrl, isAzureOpenAiUrl } from "../../../../../src/utils/azure-url-parser"
+
 import { ExtensionMessage } from "@roo/ExtensionMessage"
 
 import { useAppTranslation } from "@src/i18n/TranslationContext"
@@ -41,6 +43,12 @@ export const OpenAICompatible = ({
 	const [azureApiVersionSelected, setAzureApiVersionSelected] = useState(!!apiConfiguration?.azureApiVersion)
 	const [openAiLegacyFormatSelected, setOpenAiLegacyFormatSelected] = useState(!!apiConfiguration?.openAiLegacyFormat)
 
+	// Check if API version can be extracted from the base URL
+	const baseUrl = apiConfiguration?.openAiBaseUrl || ""
+	const extractedApiVersion = extractApiVersionFromUrl(baseUrl)
+	const isAzureUrl = isAzureOpenAiUrl(baseUrl)
+	const showApiVersionExtraction = isAzureUrl && extractedApiVersion && !azureApiVersionSelected
+
 	const [openAiModels, setOpenAiModels] = useState<Record<string, ModelInfo> | null>(null)
 
 	const [customHeaders, setCustomHeaders] = useState<[string, string][]>(() => {