feat(ai) - add observability (#20850)

**AI Chat - Tool Executions (counters, tagged with model)**
ai-chat/tool-execution-succeeded: number of tool calls invoked by the AI
that completed without error
ai-chat/tool-execution-failed: number of tool calls invoked by the AI
that threw an error
**AI Chat - Token Usage (counters, tagged with model)**
ai-chat/input-tokens: total input tokens sent to the model across all
turns
ai-chat/output-tokens: total output tokens generated by the model
ai-chat/cache-read-tokens: input tokens served from the model's prompt
cache (cheaper)
ai-chat/cache-write-tokens: input tokens written into the prompt cache
for future reuse
**AI Chat - Latency (histograms in ms, tagged with model)**
ai-chat/turn-latency-ms: total duration of a full chat turn (from stream
start to stream end)
ai-chat/step-latency-ms: duration of a single reasoning/tool-call step
within a turn
ai-chat/ttft-ms: time-to-first-token, i.e. how long until the model
starts streaming output
**MCP - Tool Executions (counters)**
mcp/tool-execution-succeeded: number of MCP tool calls that completed
successfully
mcp/tool-execution-failed: number of MCP tool calls that threw an error

packages/twenty-server/src/engine/api/common/common-query-runners/common-base-query-runner.service.ts

@@ -385,7 +385,7 @@ export abstract class CommonBaseQueryRunnerService<
         longConfig.timeWindow,
       );
     } catch (error) {
-      await this.metricsService.incrementCounter({
+      await this.metricsService.incrementCounterForEvent({
         key: MetricsKeys.CommonApiQueryRateLimited,
         shouldStoreInCache: false,
       });

packages/twenty-server/src/engine/api/mcp/mcp.module.ts

@@ -5,6 +5,7 @@ import { McpAuthGuard } from 'src/engine/api/mcp/guards/mcp-auth.guard';
 import { McpProtocolService } from 'src/engine/api/mcp/services/mcp-protocol.service';
 import { McpToolExecutorService } from 'src/engine/api/mcp/services/mcp-tool-executor.service';
 import { ApiKeyModule } from 'src/engine/core-modules/api-key/api-key.module';
+import { MetricsModule } from 'src/engine/core-modules/metrics/metrics.module';
 import { TokenModule } from 'src/engine/core-modules/auth/token/token.module';
 import { TwentyConfigModule } from 'src/engine/core-modules/twenty-config/twenty-config.module';
 import { ToolProviderModule } from 'src/engine/core-modules/tool-provider/tool-provider.module';
@@ -17,6 +18,7 @@ import { WorkspaceCacheStorageModule } from 'src/engine/workspace-cache-storage/
 @Module({
   imports: [
     ApiKeyModule,
+    MetricsModule,
     TokenModule,
     WorkspaceCacheStorageModule,
     UserRoleModule,

packages/twenty-server/src/engine/api/mcp/services/__tests__/mcp-tool-executor.service.spec.ts

@@ -4,13 +4,18 @@ import {
   MCP_PROGRESS_NOTIFICATION_METHOD,
   TOOL_CALL_PROGRESS_TOKEN_PREFIX,
 } from 'src/engine/api/mcp/constants/mcp-progress-notification.const';
+import { MetricsService } from 'src/engine/core-modules/metrics/metrics.service';
 import { McpToolExecutorService } from 'src/engine/api/mcp/services/mcp-tool-executor.service';
 
 describe('McpToolExecutorService', () => {
   let service: McpToolExecutorService;
 
   beforeEach(() => {
-    service = new McpToolExecutorService();
+    const metricsService = {
+      incrementCounterBy: jest.fn().mockResolvedValue(undefined),
+    } as unknown as MetricsService;
+
+    service = new McpToolExecutorService(metricsService);
   });
 
   describe('handleToolsListing', () => {

packages/twenty-server/src/engine/api/mcp/services/mcp-tool-executor.service.ts

@@ -3,6 +3,9 @@ import { Injectable } from '@nestjs/common';
 import { type ToolSet } from 'ai';
 import { isDefined } from 'twenty-shared/utils';
 
+import { MetricsKeys } from 'src/engine/core-modules/metrics/types/metrics-keys.type';
+import { MetricsService } from 'src/engine/core-modules/metrics/metrics.service';
+
 import { JSON_RPC_ERROR_CODE } from 'src/engine/api/mcp/constants/json-rpc-error-code.const';
 import {
   MCP_PROGRESS_NOTIFICATION_METHOD,
@@ -22,6 +25,8 @@ const unwrapJsonSchema = (schema: unknown) =>
 
 @Injectable()
 export class McpToolExecutorService {
+  constructor(private readonly metricsService: MetricsService) {}
+
   async handleToolCall(
     id: string | number,
     toolSet: ToolSet,
@@ -58,6 +63,11 @@ export class McpToolExecutorService {
         messages: [],
       });
 
+      void this.metricsService.incrementCounterBy({
+        key: MetricsKeys.McpToolExecutionSucceeded,
+        amount: 1,
+      });
+
       return wrapJsonRpcResponse(id, {
         result: {
           content: [{ type: 'text', text: JSON.stringify(result) }],
@@ -65,6 +75,11 @@ export class McpToolExecutorService {
         },
       });
     } catch (executionError) {
+      void this.metricsService.incrementCounterBy({
+        key: MetricsKeys.McpToolExecutionFailed,
+        amount: 1,
+      });
+
       return wrapJsonRpcResponse(id, {
         result: {
           content: [