Support editTools configuration for BYOK models in copilot chat extension

[yuezhang030]

We would like to propose adding editTools to the Copilot Chat model selection configuration, as shown below:

customModels:
  customoai:
    vscModelB-oswe-omai-d36-mix1-r3-rl2-s105-0216:
      name: "vscModelB-oswe-omai-d36-mix1-r3-rl2-s105-0216"
      url: "https://github-research-aoai-eastus2.openai.azure.com/openai/responses?api-version=2025-04-01-preview"
      toolCalling: true
      vision: false
      thinking: true
      maxInputTokens: 200000
      maxOutputTokens: 64000
      requiresAPIKey: true
      editTools:
        - "find-replace"
        - "multi-find-replace"

We expect the editTools configuration to work for custom models. However, it is currently not functioning as intended.

We have identified a viable fix, as demonstrated in the following code patch:

diff --git a/src/extension/byok/common/byokProvider.ts b/src/extension/byok/common/byokProvider.ts
index 23413e39..01aa3ab7 100644
--- a/src/extension/byok/common/byokProvider.ts
+++ b/src/extension/byok/common/byokProvider.ts
@@ -146,6 +146,9 @@ export function resolveModelInfo(modelId: string, providerName: string, knownMod
 	if (knownModelInfo?.requestHeaders && Object.keys(knownModelInfo.requestHeaders).length > 0) {
 		modelInfo.requestHeaders = { ...knownModelInfo.requestHeaders };
 	}
+	if (knownModelInfo?.editTools && knownModelInfo.editTools.length > 0) {
+		modelInfo.editTools = knownModelInfo.editTools;
+	}
 	return modelInfo;
 }
 
diff --git a/src/extension/byok/vscode-node/customOAIProvider.ts b/src/extension/byok/vscode-node/customOAIProvider.ts
index 772e2cf4..b3d705d1 100644
--- a/src/extension/byok/vscode-node/customOAIProvider.ts
+++ b/src/extension/byok/vscode-node/customOAIProvider.ts
@@ -142,7 +142,8 @@ export abstract class AbstractCustomOAIBYOKModelProvider extends AbstractOpenAIC
 			thinking: modelConfiguration?.thinking ?? false,
 			streaming: modelConfiguration?.streaming,
 			requestHeaders: modelConfiguration?.requestHeaders,
-			zeroDataRetentionEnabled: modelConfiguration?.zeroDataRetentionEnabled
+			zeroDataRetentionEnabled: modelConfiguration?.zeroDataRetentionEnabled,
+			editTools: modelConfiguration?.editTools
 		};
 		const modelInfo = resolveModelInfo(model.id, this._name, undefined, modelCapabilities);
 		if (modelCapabilities?.url?.includes('/responses')) {
diff --git a/src/platform/endpoint/common/endpointProvider.ts b/src/platform/endpoint/common/endpointProvider.ts
index e903a2b6..470d3512 100644
--- a/src/platform/endpoint/common/endpointProvider.ts
+++ b/src/platform/endpoint/common/endpointProvider.ts
@@ -96,6 +96,7 @@ export type IChatModelInformation = IModelAPIResponse & {
 	urlOrRequestMetadata?: string | RequestMetadata;
 	requestHeaders?: Readonly<Record<string, string>>;
 	zeroDataRetentionEnabled?: boolean;
+	editTools?: readonly EndpointEditToolName[];
 };
 
 export function isChatModelInformation(model: IModelAPIResponse): model is IChatModelInformation {
diff --git a/src/platform/endpoint/node/chatEndpoint.ts b/src/platform/endpoint/node/chatEndpoint.ts
index e0f9eb49..77bf5db0 100644
--- a/src/platform/endpoint/node/chatEndpoint.ts
+++ b/src/platform/endpoint/node/chatEndpoint.ts
@@ -31,7 +31,7 @@ import { ITokenizerProvider } from '../../tokenizer/node/tokenizer';
 import { ICAPIClientService } from '../common/capiClient';
 import { isAnthropicFamily, isGeminiFamily } from '../common/chatModelCapabilities';
 import { IDomainService } from '../common/domainService';
-import { CustomModel, IChatModelInformation, ModelSupportedEndpoint } from '../common/endpointProvider';
+import { CustomModel, EndpointEditToolName, IChatModelInformation, ModelSupportedEndpoint } from '../common/endpointProvider';
 import { createMessagesRequestBody, processResponseFromMessagesEndpoint } from './messagesApi';
 import { createResponsesRequestBody, processResponseFromChatEndpoint } from './responsesApi';
 
@@ -131,6 +131,7 @@ export class ChatEndpoint implements IChatEndpoint {
 	public readonly restrictedToSkus?: string[] | undefined;
 	public readonly customModel?: CustomModel | undefined;
 	public readonly maxPromptImages?: number | undefined;
+	public readonly supportedEditTools?: readonly EndpointEditToolName[] | undefined;
 
 	private readonly _supportsStreaming: boolean;
 
@@ -167,6 +168,7 @@ export class ChatEndpoint implements IChatEndpoint {
 		this._supportsStreaming = !!modelMetadata.capabilities.supports.streaming;
 		this.customModel = modelMetadata.custom_model;
 		this.maxPromptImages = modelMetadata.capabilities.limits?.vision?.max_prompt_images;
+		this.supportedEditTools = modelMetadata.editTools;
 	}
 
 	public getExtraHeaders(location?: ChatLocation): Record<string, string> {

I built a local extension incorporating this code fix, and it works as expected.

Therefore, we would like to request an official fix to properly support the editTools configuration for custom models.

[yuezhang030]

I created a code change PR here: microsoft/vscode-copilot-chat#4317