Support BYOK endpoints for Inline suggestions (fix #318545)

extensions/copilot/package.json

@@ -1869,6 +1869,12 @@
               "title": "API Key",
               "markdownDeprecationMessage": "**Deprecated.** Use the `customendpoint` provider (\"Custom Endpoint\") instead. It supports the Chat Completions API, the Responses API, and the Messages API — selectable per model via the `apiType` property."
             },
+            "completionsUrl": {
+              "type": "string",
+              "pattern": "^https?://.+",
+              "patternErrorMessage": "URL must start with http:// or https://",
+              "markdownDescription": "Default full URL used **verbatim** for inline code completions (FIM) requests for models in this group, e.g. DeepSeek: `https://api.deepseek.com/beta/completions`, or SiliconFlow: `https://api.siliconflow.cn/v1/completions` / `https://api.siliconflow.com/v1/completions`. Individual models can override this with their own `completionsUrl` property. When neither is set, the group's models are only available for chat."
+            },
             "models": {
               "type": "array",
               "markdownDeprecationMessage": "**Deprecated.** Use the `customendpoint` provider (\"Custom Endpoint\") instead. It supports the Chat Completions API, the Responses API, and the Messages API — selectable per model via the `apiType` property.",
@@ -1904,6 +1910,12 @@
                     "type": "string",
                     "markdownDescription": "URL endpoint for the custom OpenAI-compatible model.\n\n**Important:** Base URLs default to Chat Completions API. Explicit API paths including `/responses` or `/chat/completions` are respected."
                   },
+                  "completionsUrl": {
+                    "type": "string",
+                    "pattern": "^https?://.+",
+                    "patternErrorMessage": "URL must start with http:// or https://",
+                    "markdownDescription": "Full URL used **verbatim** for inline code completions (FIM) requests, e.g. DeepSeek: `https://api.deepseek.com/beta/completions`, or SiliconFlow: `https://api.siliconflow.cn/v1/completions` / `https://api.siliconflow.com/v1/completions`. When omitted, the group-level `completionsUrl` is used; if neither is set, this model is only available for chat, not for inline code completions."
+                  },
                   "toolCalling": {
                     "type": "boolean",
                     "description": "Whether the model supports tool calling"
@@ -2035,6 +2047,12 @@
               "title": "API Type",
               "markdownDescription": "Default request/response format for models in this group. Individual models can override this with their own `apiType` property; when both are unset the type is inferred from the URL path."
             },
+            "completionsUrl": {
+              "type": "string",
+              "pattern": "^https?://.+",
+              "patternErrorMessage": "URL must start with http:// or https://",
+              "markdownDescription": "Default full URL used **verbatim** for inline code completions (FIM) requests for models in this group, e.g. DeepSeek: `https://api.deepseek.com/beta/completions`, or SiliconFlow: `https://api.siliconflow.cn/v1/completions` / `https://api.siliconflow.com/v1/completions`. Individual models can override this with their own `completionsUrl` property. When neither is set, the group's models are only available for chat."
+            },
             "models": {
               "type": "array",
               "defaultSnippets": [
@@ -2071,6 +2089,12 @@
                     "patternErrorMessage": "URL must start with http:// or https://",
                     "markdownDescription": "URL endpoint for the model.\n\n**Important:** Base URLs default to Chat Completions API. Explicit API paths are respected: `/chat/completions`, `/responses`, and `/v1/messages` (Anthropic-compatible). Use the `apiType` property to override the request/response format independently of the URL."
                   },
+                  "completionsUrl": {
+                    "type": "string",
+                    "pattern": "^https?://.+",
+                    "patternErrorMessage": "URL must start with http:// or https://",
+                    "markdownDescription": "Full URL used **verbatim** for inline code completions (FIM) requests, e.g. DeepSeek: `https://api.deepseek.com/beta/completions`, or SiliconFlow: `https://api.siliconflow.cn/v1/completions` / `https://api.siliconflow.com/v1/completions`. When omitted, the group-level `completionsUrl` is used; if neither is set, this model is only available for chat, not for inline code completions."
+                  },
                   "apiType": {
                     "type": "string",
                     "enum": [

extensions/copilot/src/extension/byok/common/byokCompletionModels.ts

@@ -0,0 +1,193 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { IStringDictionary } from '../../../util/vs/base/common/collections';
+import { Emitter, Event } from '../../../util/vs/base/common/event';
+
+/**
+ * Vendors whose `chatLanguageModels.json` groups can back inline code completions
+ * via OpenAI-compatible FIM endpoints.
+ */
+export const BYOK_COMPLETION_VENDORS = ['customendpoint', 'customoai'];
+
+/**
+ * A custom OpenAI-compatible model usable for inline code completions (FIM).
+ * The FIM request is POSTed verbatim to {@link ByokCompletionModel.completionsUrl}.
+ */
+export interface ByokCompletionModel {
+	/** Identifier usable in `github.copilot.selectedCompletionModel`. */
+	readonly id: string;
+	/** Display name for the model picker. */
+	readonly label: string;
+	/** Vendor id ('customendpoint' | 'customoai'). */
+	readonly vendor: string;
+	/** The chatLanguageModels.json group name the model comes from. */
+	readonly groupName: string;
+	/** Full URL the FIM request is POSTed to. Used verbatim — no path derivation. */
+	readonly completionsUrl: string;
+	/** API key resolved from secret storage by the language models service. */
+	readonly apiKey?: string;
+	/** Model identifier sent in the request body `model` field. */
+	readonly model: string;
+	/** Custom headers from the model configuration. */
+	readonly requestHeaders?: Record<string, string>;
+}
+
+interface RegisteredGroupConfig {
+	readonly vendor: string;
+	readonly groupName: string;
+	readonly configuration: IStringDictionary<unknown> | undefined;
+}
+
+const registeredGroupConfigs = new Map<string, RegisteredGroupConfig>();
+let completionModels: ByokCompletionModel[] = [];
+
+const _onDidChange = new Emitter<void>();
+export const onDidChangeByokCompletionModels: Event<void> = _onDidChange.event;
+
+/**
+ * Called by the BYOK language model chat providers (see
+ * `AbstractLanguageModelChatProvider.provideLanguageModelChatInformation`) once the
+ * language models service has resolved a `chatLanguageModels.json` group. At that
+ * point secrets such as `${input:...}` api keys are already decoded, so this is the
+ * only place where the completion pipeline can obtain them.
+ *
+ * `groupName === undefined` marks the start of a new resolution pass: the language
+ * models service invokes the provider once without a group before the per-group
+ * calls, so every group previously seen for this vendor is dropped and then
+ * re-added from the groups that still exist. This keeps the registry in sync when
+ * a group is deleted from the file while the extension is running (hot swap).
+ */
+export function updateByokCompletionModelConfig(vendor: string, groupName: string | undefined, configuration: IStringDictionary<unknown> | undefined): void {
+	if (groupName === undefined) {
+		// Start of a new resolution pass for this vendor: drop its stale groups so
+		// deleted groups do not linger in the registry and in the model picker.
+		for (const [key, config] of registeredGroupConfigs) {
+			if (config.vendor === vendor) {
+				registeredGroupConfigs.delete(key);
+			}
+		}
+		recomputeCompletionModels();
+		return;
+	}
+	const key = `${vendor}/${groupName}`;
+	if (!configuration) {
+		registeredGroupConfigs.delete(key);
+	} else {
+		registeredGroupConfigs.set(key, { vendor, groupName, configuration });
+	}
+	recomputeCompletionModels();
+}
+
+/** Clears all registered group configs, e.g. when BYOK is disabled by enterprise policy. */
+export function clearByokCompletionModelConfigs(): void {
+	registeredGroupConfigs.clear();
+	recomputeCompletionModels();
+}
+
+export function getByokCompletionModels(): readonly ByokCompletionModel[] {
+	return completionModels;
+}
+
+export function getByokCompletionModelById(id: string): ByokCompletionModel | undefined {
+	// Exact match on the generated identifier first, then fall back to the
+	// `group/id` and `vendor/group/id` forms used by the chat model picker
+	// (`toModelIdentifier`), so user-entered values like
+	// `customendpoint/DS-oss/deepseek-v4-flash` also resolve.
+	return completionModels.find(model =>
+		model.id === id
+		|| `${model.groupName}/${model.model}` === id
+		|| `${model.vendor}/${model.groupName}/${model.model}` === id
+	);
+}
+
+function recomputeCompletionModels(): void {
+	const models: ByokCompletionModel[] = [];
+	const usedIds = new Set<string>();
+
+	for (const { vendor, groupName, configuration } of registeredGroupConfigs.values()) {
+		if (!BYOK_COMPLETION_VENDORS.includes(vendor)) {
+			continue;
+		}
+		parseGroupConfiguration(models, usedIds, vendor, groupName, configuration);
+	}
+
+	if (JSON.stringify(models) !== JSON.stringify(completionModels)) {
+		completionModels = models;
+		_onDidChange.fire();
+	}
+}
+
+function parseGroupConfiguration(models: ByokCompletionModel[], usedIds: Set<string>, vendor: string, groupName: string, configuration: IStringDictionary<unknown> | undefined): void {
+	if (!configuration || typeof configuration !== 'object') {
+		return;
+	}
+	const groupCompletionsUrl = asOptionalString(configuration.completionsUrl);
+	const apiKey = asOptionalString(configuration.apiKey);
+	const configuredModels = configuration.models;
+	if (!Array.isArray(configuredModels)) {
+		return;
+	}
+	for (const entry of configuredModels) {
+		if (!entry || typeof entry !== 'object') {
+			continue;
+		}
+		const model = entry as IStringDictionary<unknown>;
+		const modelId = asOptionalString(model.id);
+		const url = asOptionalString(model.url);
+		if (!modelId || !url) {
+			// The model must have an id and a chat URL to be usable at all.
+			continue;
+		}
+		const completionsUrl = asOptionalString(model.completionsUrl) ?? groupCompletionsUrl;
+		if (!completionsUrl || !/^https?:\/\//.test(completionsUrl)) {
+			// No (valid) completions URL configured: the model is chat-only.
+			continue;
+		}
+		const id = computeUniqueId(modelId, groupName, vendor, usedIds);
+		usedIds.add(id);
+		models.push({
+			id,
+			label: asOptionalString(model.name) ?? modelId,
+			vendor,
+			groupName,
+			completionsUrl,
+			...(apiKey ? { apiKey } : {}),
+			model: modelId,
+			...(toStringRecord(model.requestHeaders) ? { requestHeaders: toStringRecord(model.requestHeaders) } : {}),
+		});
+	}
+}
+
+/**
+ * The raw model id is the primary identifier; when multiple groups define models
+ * with the same id, they are disambiguated by group name and vendor.
+ */
+function computeUniqueId(modelId: string, groupName: string, vendor: string, usedIds: Set<string>): string {
+	const candidates = [modelId, `${groupName}/${modelId}`, `${vendor}/${groupName}/${modelId}`];
+	for (const candidate of candidates) {
+		if (!usedIds.has(candidate)) {
+			return candidate;
+		}
+	}
+	return `${vendor}/${groupName}/${modelId}/${usedIds.size}`;
+}
+
+function asOptionalString(value: unknown): string | undefined {
+	return typeof value === 'string' && value.length > 0 ? value : undefined;
+}
+
+function toStringRecord(value: unknown): Record<string, string> | undefined {
+	if (!value || typeof value !== 'object') {
+		return undefined;
+	}
+	const record: Record<string, string> = {};
+	for (const [key, entry] of Object.entries(value)) {
+		if (typeof entry === 'string') {
+			record[key] = entry;
+		}
+	}
+	return Object.keys(record).length > 0 ? record : undefined;
+}