Add Anthropic (Claude) as a model provider

.gitignore

@@ -26,6 +26,7 @@ report.[0-9]_.[0-9]_.[0-9]_.[0-9]_.json
 .eslintcache
 .cache
 *.tsbuildinfo
+.bun-cache/
 
 # IntelliJ based IDEs
 .idea

package.json

@@ -58,6 +58,7 @@
     "typescript": "^5"
   },
   "dependencies": {
+    "@anthropic-ai/sdk": "^0.87.0",
     "commander": "^14.0.3",
     "gray-matter": "^4.0.3",
     "ink": "^6.8.0",

src/cli/bootstrap/model-wizard.tsx

@@ -9,11 +9,12 @@ import { currentTheme } from "../tui/themes";
 
 type Step = "provider" | "apiKey" | "modelName" | "baseURL" | "confirm";
 
-function buildModelEntry(baseURL: string, apiKey: string, modelName: string): ModelEntry {
+function buildModelEntry(baseURL: string, apiKey: string, modelName: string, provider: ModelEntry["provider"]): ModelEntry {
   return {
     name: modelName.trim(),
     baseURL: baseURL.trim(),
     APIKey: apiKey.trim(),
+    provider,
   };
 }
 
@@ -75,7 +76,7 @@ function ModelWizard({ onComplete, onAbort }: ModelWizardProps) {
 
   const finishWithBaseURL = (url: string) => {
     setCustomBaseURL(url);
-    const entry = buildModelEntry(url, apiKey, modelName);
+    const entry = buildModelEntry(url, apiKey, modelName, selectedProvider.providerType);
     setPendingEntry(entry);
     setStep("confirm");
   };
@@ -84,7 +85,7 @@ function ModelWizard({ onComplete, onAbort }: ModelWizardProps) {
     if (!selectedProvider.baseURL) {
       setStep("baseURL");
     } else {
-      const entry = buildModelEntry(selectedProvider.baseURL, apiKey, modelName);
+      const entry = buildModelEntry(selectedProvider.baseURL, apiKey, modelName, selectedProvider.providerType);
       setPendingEntry(entry);
       setStep("confirm");
     }

src/cli/config/schema.ts

@@ -4,6 +4,8 @@ export const modelEntrySchema = z.object({
   name: z.string().min(1),
   baseURL: z.string().min(1),
   APIKey: z.string().min(1),
+  /** Provider type: "openai" (default) or "anthropic". */
+  provider: z.enum(["openai", "anthropic"]).optional().default("openai"),
 });
 
 export const helixentConfigSchema = z.object({

src/cli/index.tsx

@@ -7,7 +7,9 @@ import { validateIntegrity } from "@/cli/bootstrap";
 import { registerCommands } from "@/cli/commands";
 import { loadConfig } from "@/cli/config";
 import { createCodingAgent, globalApprovalManager } from "@/coding";
+import { AnthropicModelProvider } from "@/community/anthropic";
 import { OpenAIModelProvider } from "@/community/openai";
+import type { ModelProvider } from "@/foundation";
 import { Model } from "@/foundation";
 
 import { App } from "./tui";
@@ -38,10 +40,18 @@ if (args.length > 0) {
     throw new Error("No models configured. Run `helixent config model add` to add one.");
   }
 
-  const provider = new OpenAIModelProvider({
-    baseURL: entry.baseURL,
-    apiKey: entry.APIKey,
-  });
+  let provider: ModelProvider;
+  if (entry.provider === "anthropic") {
+    provider = new AnthropicModelProvider({
+      baseURL: entry.baseURL,
+      apiKey: entry.APIKey,
+    });
+  } else {
+    provider = new OpenAIModelProvider({
+      baseURL: entry.baseURL,
+      apiKey: entry.APIKey,
+    });
+  }
 
   const model = new Model(entry.name, provider, {
     max_tokens: 16 * 1024,

src/cli/model-providers.ts

@@ -1,22 +1,27 @@
+export type ProviderType = "openai" | "anthropic";
+
 export type ModelProviderConfig = {
   label: string;
   id: string;
   baseURL: string;
+  providerType: ProviderType;
 };
 
 export const MODEL_PROVIDERS: ModelProviderConfig[] = [
-  { label: "OpenAI", id: "openai", baseURL: "https://api.openai.com/v1" },
-  { label: "Volcengine - General", id: "volcengine", baseURL: "https://ark.cn-beijing.volces.com/api/v3" },
+  { label: "Anthropic (Claude)", id: "anthropic", baseURL: "https://api.anthropic.com", providerType: "anthropic" },
+  { label: "OpenAI", id: "openai", baseURL: "https://api.openai.com/v1", providerType: "openai" },
+  { label: "Volcengine - General", id: "volcengine", baseURL: "https://ark.cn-beijing.volces.com/api/v3", providerType: "openai" },
   {
     label: "Volcengine - Coding Plan",
     id: "volcengine_coding_plan",
     baseURL: "https://ark.cn-beijing.volces.com/api/coding/v3",
+    providerType: "openai",
   },
-  { label: "Qwen (Aliyun)", id: "qwen", baseURL: "https://dashscope.aliyuncs.com/compatible-mode/v1" },
-  { label: "Minimax (Domestic)", id: "minimax_cn", baseURL: "https://api.minimaxi.com/v1" },
-  { label: "Minimax (Global)", id: "minimax_global", baseURL: "https://api.minimax.io/v1" },
-  { label: "GLM (Zhipu AI)", id: "glm", baseURL: "https://open.bigmodel.cn/api/paas/v4" },
-  { label: "Kimi (Moonshot)", id: "kimi", baseURL: "https://api.moonshot.cn/v1" },
-  { label: "DeepSeek (OpenAI compatible)", id: "deepseek", baseURL: "https://api.deepseek.com/v1" },
-  { label: "Other", id: "other", baseURL: "" },
+  { label: "Qwen (Aliyun)", id: "qwen", baseURL: "https://dashscope.aliyuncs.com/compatible-mode/v1", providerType: "openai" },
+  { label: "Minimax (Domestic)", id: "minimax_cn", baseURL: "https://api.minimaxi.com/v1", providerType: "openai" },
+  { label: "Minimax (Global)", id: "minimax_global", baseURL: "https://api.minimax.io/v1", providerType: "openai" },
+  { label: "GLM (Zhipu AI)", id: "glm", baseURL: "https://open.bigmodel.cn/api/paas/v4", providerType: "openai" },
+  { label: "Kimi (Moonshot)", id: "kimi", baseURL: "https://api.moonshot.cn/v1", providerType: "openai" },
+  { label: "DeepSeek (OpenAI compatible)", id: "deepseek", baseURL: "https://api.deepseek.com/v1", providerType: "openai" },
+  { label: "Other", id: "other", baseURL: "", providerType: "openai" },
 ];

src/community/anthropic/index.ts

@@ -0,0 +1 @@
+export * from "./model-provider";

src/community/anthropic/model-provider.ts

@@ -0,0 +1,88 @@
+import Anthropic from "@anthropic-ai/sdk";
+
+import type { AssistantMessage, ModelProvider, ModelProviderInvokeParams, TokenUsage } from "@/foundation";
+
+import { StreamAccumulator } from "./stream-utils";
+import {
+  convertToAnthropicMessages,
+  convertToAnthropicTools,
+  extractSystemPrompt,
+  parseAssistantMessage,
+} from "./utils";
+
+/**
+ * A provider for the Anthropic API (Claude models).
+ */
+export class AnthropicModelProvider implements ModelProvider {
+  _client: Anthropic;
+
+  constructor({ baseURL, apiKey }: { baseURL?: string; apiKey?: string } = {}) {
+    // Only pass baseURL if it differs from the SDK default, so the SDK's
+    // own URL construction logic is used for the standard Anthropic endpoint.
+    const isDefaultURL = !baseURL || baseURL === "https://api.anthropic.com";
+    this._client = new Anthropic({
+      ...(isDefaultURL ? {} : { baseURL }),
+      apiKey,
+    });
+  }
+
+  async invoke(params: ModelProviderInvokeParams) {
+    const response = await this._client.messages.create(this._baseMessageParams(params), {
+      signal: params.signal,
+    });
+    return parseAssistantMessage(response, toTokenUsage(response.usage));
+  }
+
+  async *stream(params: ModelProviderInvokeParams): AsyncGenerator<AssistantMessage> {
+    const response = await this._client.messages.create(
+      { ...this._baseMessageParams(params), stream: true },
+      { signal: params.signal },
+    );
+
+    const acc = new StreamAccumulator();
+    for await (const event of response) {
+      acc.push(event);
+      yield acc.snapshot();
+    }
+  }
+
+  private _baseMessageParams({
+    model,
+    messages,
+    tools,
+    options,
+  }: ModelProviderInvokeParams): Anthropic.MessageCreateParamsNonStreaming {
+    const system = extractSystemPrompt(messages);
+    const anthropicMessages = convertToAnthropicMessages(messages);
+    const anthropicTools = tools ? convertToAnthropicTools(tools) : undefined;
+
+    // Normalize options for Anthropic's API.
+    // When thinking is enabled, Anthropic requires `budget_tokens`.
+    // Default the budget to max_tokens minus a small buffer for the response.
+    const normalizedOptions = { ...options };
+    const thinking = normalizedOptions.thinking as { type: string; budget_tokens?: number } | undefined;
+    if (thinking?.type === "enabled" && !thinking.budget_tokens) {
+      const maxTokens = (normalizedOptions.max_tokens as number | undefined) ?? 8192;
+      thinking.budget_tokens = Math.floor(maxTokens * 0.8);
+      normalizedOptions.thinking = thinking;
+    }
+
+    return {
+      model,
+      max_tokens: 8192,
+      messages: anthropicMessages,
+      ...(system ? { system } : {}),
+      ...(anthropicTools && anthropicTools.length > 0 ? { tools: anthropicTools } : {}),
+      ...normalizedOptions,
+    };
+  }
+}
+
+function toTokenUsage(usage?: Anthropic.Usage): TokenUsage | undefined {
+  if (!usage) return undefined;
+  return {
+    promptTokens: usage.input_tokens ?? 0,
+    completionTokens: usage.output_tokens ?? 0,
+    totalTokens: (usage.input_tokens ?? 0) + (usage.output_tokens ?? 0),
+  };
+}