feat(M3-002): implement AnthropicAdapter for Claude Sonnet 4.6, Opus 4.6, and Haiku 4.5 (#309)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/gateway/package.json

@@ -12,18 +12,19 @@
     "test": "vitest run --passWithNoTests"
   },
   "dependencies": {
+    "@anthropic-ai/sdk": "^0.80.0",
     "@fastify/helmet": "^13.0.2",
     "@mariozechner/pi-ai": "~0.57.1",
     "@mariozechner/pi-coding-agent": "~0.57.1",
     "@modelcontextprotocol/sdk": "^1.27.1",
     "@mosaic/auth": "workspace:^",
-    "@mosaic/queue": "workspace:^",
     "@mosaic/brain": "workspace:^",
     "@mosaic/coord": "workspace:^",
     "@mosaic/db": "workspace:^",
     "@mosaic/discord-plugin": "workspace:^",
     "@mosaic/log": "workspace:^",
     "@mosaic/memory": "workspace:^",
+    "@mosaic/queue": "workspace:^",
     "@mosaic/telegram-plugin": "workspace:^",
     "@mosaic/types": "workspace:^",
     "@nestjs/common": "^11.0.0",

apps/gateway/src/agent/adapters/anthropic.adapter.ts

@@ -0,0 +1,191 @@
+import { Logger } from '@nestjs/common';
+import Anthropic from '@anthropic-ai/sdk';
+import type { ModelRegistry } from '@mariozechner/pi-coding-agent';
+import type {
+  CompletionEvent,
+  CompletionParams,
+  IProviderAdapter,
+  ModelInfo,
+  ProviderHealth,
+} from '@mosaic/types';
+
+/**
+ * Anthropic provider adapter.
+ *
+ * Registers Claude models with the Pi ModelRegistry via the Anthropic SDK.
+ * Configuration is driven by environment variables:
+ *   ANTHROPIC_API_KEY — Anthropic API key (required)
+ */
+export class AnthropicAdapter implements IProviderAdapter {
+  readonly name = 'anthropic';
+
+  private readonly logger = new Logger(AnthropicAdapter.name);
+  private client: Anthropic | null = null;
+  private registeredModels: ModelInfo[] = [];
+
+  constructor(private readonly registry: ModelRegistry) {}
+
+  async register(): Promise<void> {
+    const apiKey = process.env['ANTHROPIC_API_KEY'];
+    if (!apiKey) {
+      this.logger.warn('Skipping Anthropic provider registration: ANTHROPIC_API_KEY not set');
+      return;
+    }
+
+    this.client = new Anthropic({ apiKey });
+
+    const models: ModelInfo[] = [
+      {
+        id: 'claude-opus-4-6',
+        provider: 'anthropic',
+        name: 'Claude Opus 4.6',
+        reasoning: true,
+        contextWindow: 200000,
+        maxTokens: 32000,
+        inputTypes: ['text', 'image'],
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+      },
+      {
+        id: 'claude-sonnet-4-6',
+        provider: 'anthropic',
+        name: 'Claude Sonnet 4.6',
+        reasoning: true,
+        contextWindow: 200000,
+        maxTokens: 16000,
+        inputTypes: ['text', 'image'],
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+      },
+      {
+        id: 'claude-haiku-4-5',
+        provider: 'anthropic',
+        name: 'Claude Haiku 4.5',
+        reasoning: false,
+        contextWindow: 200000,
+        maxTokens: 8192,
+        inputTypes: ['text', 'image'],
+        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+      },
+    ];
+
+    this.registry.registerProvider('anthropic', {
+      apiKey,
+      baseUrl: 'https://api.anthropic.com',
+      api: 'anthropic' as never,
+      models: models.map((m) => ({
+        id: m.id,
+        name: m.name,
+        reasoning: m.reasoning,
+        input: m.inputTypes as ('text' | 'image')[],
+        cost: m.cost,
+        contextWindow: m.contextWindow,
+        maxTokens: m.maxTokens,
+      })),
+    });
+
+    this.registeredModels = models;
+
+    this.logger.log(
+      `Anthropic provider registered with models: ${models.map((m) => m.id).join(', ')}`,
+    );
+  }
+
+  listModels(): ModelInfo[] {
+    return this.registeredModels;
+  }
+
+  async healthCheck(): Promise<ProviderHealth> {
+    const apiKey = process.env['ANTHROPIC_API_KEY'];
+    if (!apiKey) {
+      return {
+        status: 'down',
+        lastChecked: new Date().toISOString(),
+        error: 'ANTHROPIC_API_KEY not configured',
+      };
+    }
+
+    const start = Date.now();
+
+    try {
+      const client = this.client ?? new Anthropic({ apiKey });
+      await client.models.list({ limit: 1 });
+      const latencyMs = Date.now() - start;
+      return { status: 'healthy', latencyMs, lastChecked: new Date().toISOString() };
+    } catch (err) {
+      const latencyMs = Date.now() - start;
+      const error = err instanceof Error ? err.message : String(err);
+      const status = error.includes('401') || error.includes('403') ? 'degraded' : 'down';
+      return { status, latencyMs, lastChecked: new Date().toISOString(), error };
+    }
+  }
+
+  /**
+   * Stream a completion from Anthropic using the messages API.
+   * Maps Anthropic streaming events to the CompletionEvent format.
+   *
+   * Note: Currently reserved for future direct-completion use. The Pi SDK
+   * integration routes completions through ModelRegistry / AgentSession.
+   */
+  async *createCompletion(params: CompletionParams): AsyncIterable<CompletionEvent> {
+    const apiKey = process.env['ANTHROPIC_API_KEY'];
+    if (!apiKey) {
+      throw new Error('AnthropicAdapter: ANTHROPIC_API_KEY not configured');
+    }
+
+    const client = this.client ?? new Anthropic({ apiKey });
+
+    // Separate system messages from user/assistant messages
+    const systemMessages = params.messages.filter((m) => m.role === 'system');
+    const conversationMessages = params.messages.filter((m) => m.role !== 'system');
+
+    const systemPrompt =
+      systemMessages.length > 0 ? systemMessages.map((m) => m.content).join('\n') : undefined;
+
+    const stream = await client.messages.stream({
+      model: params.model,
+      max_tokens: params.maxTokens ?? 1024,
+      ...(systemPrompt !== undefined ? { system: systemPrompt } : {}),
+      messages: conversationMessages.map((m) => ({
+        role: m.role as 'user' | 'assistant',
+        content: m.content,
+      })),
+      ...(params.temperature !== undefined ? { temperature: params.temperature } : {}),
+      ...(params.tools && params.tools.length > 0
+        ? {
+            tools: params.tools.map((t) => ({
+              name: t.name,
+              description: t.description,
+              input_schema: t.parameters as Anthropic.Tool['input_schema'],
+            })),
+          }
+        : {}),
+    });
+
+    for await (const event of stream) {
+      if (event.type === 'content_block_delta' && event.delta.type === 'text_delta') {
+        yield { type: 'text_delta', content: event.delta.text };
+      } else if (event.type === 'content_block_delta' && event.delta.type === 'input_json_delta') {
+        yield { type: 'tool_call', name: '', arguments: event.delta.partial_json };
+      } else if (event.type === 'message_delta' && event.usage) {
+        yield {
+          type: 'done',
+          usage: {
+            inputTokens:
+              (event as { usage: { input_tokens?: number; output_tokens: number } }).usage
+                .input_tokens ?? 0,
+            outputTokens: event.usage.output_tokens,
+          },
+        };
+      }
+    }
+
+    // Emit final done event with full usage from the completed message
+    const finalMessage = await stream.finalMessage();
+    yield {
+      type: 'done',
+      usage: {
+        inputTokens: finalMessage.usage.input_tokens,
+        outputTokens: finalMessage.usage.output_tokens,
+      },
+    };
+  }
+}

apps/gateway/src/agent/adapters/index.ts

@@ -1 +1,2 @@
 export { OllamaAdapter } from './ollama.adapter.js';
+export { AnthropicAdapter } from './anthropic.adapter.js';

apps/gateway/src/agent/provider.service.ts

@@ -8,7 +8,7 @@ import type {
   ProviderHealth,
   ProviderInfo,
 } from '@mosaic/types';
-import { AnthropicAdapter, OllamaAdapter, OpenAIAdapter } from './adapters/index.js';
+import { AnthropicAdapter, OllamaAdapter } from './adapters/index.js';
 import type { TestConnectionResultDto } from './provider.dto.js';
 
 /** Default health check interval in seconds */
@@ -42,11 +42,7 @@ export class ProviderService implements OnModuleInit, OnModuleDestroy {
     this.registry = new ModelRegistry(authStorage);
 
     // Build the default set of adapters that rely on the registry
-    this.adapters = [
-      new OllamaAdapter(this.registry),
-      new AnthropicAdapter(this.registry),
-      new OpenAIAdapter(this.registry),
-    ];
+    this.adapters = [new OllamaAdapter(this.registry), new AnthropicAdapter(this.registry)];
 
     // Run all adapter registrations first (Ollama, Anthropic, and any future adapters)
     await this.registerAll();