Track AI usage

apps/web/src/app/api/ai/journl-agent/route.ts

@@ -1,5 +1,6 @@
 import { journlAgent } from "~/ai/mastra/agents/journl-agent";
 import { getSession } from "~/auth/server";
+import { api } from "~/trpc/server";
 
 export const maxDuration = 30; // Allow streaming responses up to 30 seconds
 
@@ -13,7 +14,32 @@ export async function POST(req: Request) {
       return new Response("Unauthorized", { status: 401 });
     }
 
-    const result = await journlAgent.stream(messages);
+    const result = await journlAgent.stream(messages, {
+      onFinish: async (result) => {
+        const modelData = await journlAgent.getModel();
+
+        const provider = modelData.provider;
+        const model = modelData.modelId;
+
+        if (result.usage && session.user?.id) {
+          await api.usage.trackAiModelUsage({
+            metrics: [
+              {
+                quantity: result.usage.promptTokens,
+                unit: "input_tokens",
+              },
+              {
+                quantity: result.usage.completionTokens,
+                unit: "output_tokens",
+              },
+            ],
+            model_id: model,
+            model_provider: provider,
+            user_id: session.user.id,
+          });
+        }
+      },
+    });
 
     return result.toDataStreamResponse({
       getErrorMessage(error) {

apps/web/src/app/api/supabase/embed-document/route.ts

@@ -10,7 +10,7 @@ import removeMarkdown from "remove-markdown";
 import type { z } from "zod/v4";
 import { model } from "~/ai/providers/openai/embedding";
 import { schema } from "~/components/editor/block-schema";
-import { embedder } from "~/trpc/server";
+import { api, embedder } from "~/trpc/server";
 import { handler } from "../_lib/webhook-handler";
 
 const CHUNK_PARAMS: ChunkParams = {
@@ -102,14 +102,23 @@ export const POST = handler(zDocumentEmbeddingTask, async (payload) => {
     const mDocument =
       await MDocument.fromMarkdown(markdown).chunk(CHUNK_PARAMS);
 
-    // ! TODO: Here's where we get the usage tokens, we must process these in a different transaction
-    // ! To guarantee that the usage is tracked regardless of the success of the embedding.
-    const { embeddings, usage: _usage } = await embedMany({
+    const { embeddings, usage } = await embedMany({
       maxRetries: 5,
       model,
       values: mDocument.map((chunk) => chunk.text),
     });
 
+    await api.usage.trackAiModelUsage({
+      metadata: {
+        document_id: document.id,
+        model_version: model.specificationVersion,
+      },
+      metrics: [{ quantity: usage.tokens, unit: "tokens" }],
+      model_id: model.modelId,
+      model_provider: model.provider,
+      user_id: document.user_id,
+    });
+
     const insertions: z.infer<typeof zInsertDocumentEmbedding>[] = [];
 
     for (const [index, embedding] of embeddings.entries()) {

packages/api/src/api-router/index.ts

@@ -5,6 +5,7 @@ import { documentRouter } from "./document.js";
 import { journalRouter } from "./journal.js";
 import { notesRouter } from "./notes.js";
 import { pagesRouter } from "./pages.js";
+import { usageRouter } from "./usage.js";
 
 export const apiRouter = createTRPCRouter({
   auth: authRouter,
@@ -13,6 +14,7 @@ export const apiRouter = createTRPCRouter({
   journal: journalRouter,
   notes: notesRouter,
   pages: pagesRouter,
+  usage: usageRouter,
 });
 
 export type ApiRouter = typeof apiRouter;

packages/api/src/api-router/usage.ts

@@ -0,0 +1,52 @@
+import { eq } from "@acme/db";
+import { UsageEvent, UsageEventStatus } from "@acme/db/schema";
+import { TRPCError, type TRPCRouterRecord } from "@trpc/server";
+import { z } from "zod/v4";
+import { publicProcedure } from "../trpc.js";
+
+export const usageRouter = {
+  trackAiModelUsage: publicProcedure
+    .input(
+      z.object({
+        metadata: z.record(z.string(), z.string()).optional(),
+        metrics: z.array(z.object({ quantity: z.number(), unit: z.string() })),
+        model_id: z.string(),
+        model_provider: z.string(),
+        user_id: z.string(),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      try {
+        return await ctx.db.insert(UsageEvent).values(input);
+      } catch (error) {
+        console.error("Database error in usage.createUsageEvent:", error);
+        throw new TRPCError({
+          code: "INTERNAL_SERVER_ERROR",
+          message: "Failed to create usage event",
+        });
+      }
+    }),
+  updateUsageEventStatus: publicProcedure
+    .input(
+      z.object({
+        id: z.string(),
+        status: z.enum(UsageEventStatus.enumValues),
+      }),
+    )
+    .mutation(async ({ ctx, input }) => {
+      try {
+        return await ctx.db
+          .update(UsageEvent)
+          .set({
+            status: input.status,
+          })
+          .where(eq(UsageEvent.id, input.id));
+      } catch (error) {
+        console.error("Database error in usage.processUsageEvent:", error);
+        throw new TRPCError({
+          code: "INTERNAL_SERVER_ERROR",
+          message: "Failed to process usage event",
+        });
+      }
+    }),
+} satisfies TRPCRouterRecord;

packages/db/src/schema.ts

@@ -9,3 +9,4 @@ export * from "./core/document-embedding.schema.js";
 export * from "./core/document-embedding-task.schema.js";
 export * from "./core/journal-entry.schema.js";
 export * from "./core/page.schema.js";
+export * from "./usage/usage-event.schema.js";

packages/db/src/usage/usage-event.schema.ts

@@ -0,0 +1,31 @@
+import { jsonb, pgEnum, pgTable, text, timestamp } from "drizzle-orm/pg-core";
+import { user } from "../schema.js";
+
+type UsageEventMetrics = {
+  unit: string;
+  quantity: number;
+};
+
+export const UsageEventStatus = pgEnum("usage_event_status", [
+  "pending",
+  "processed",
+  "failed",
+]);
+
+export const UsageEvent = pgTable("usage_event", (t) => ({
+  id: t.uuid().notNull().primaryKey().defaultRandom(),
+  created_at: timestamp().defaultNow(),
+  updated_at: timestamp()
+    .defaultNow()
+    .$onUpdateFn(() => new Date()),
+  user_id: text()
+    .notNull()
+    .references(() => user.id),
+  model_id: text().notNull(),
+  model_provider: text().notNull(),
+  metadata: jsonb(),
+  metrics: jsonb().$type<UsageEventMetrics[]>().notNull(),
+  status: UsageEventStatus().notNull().default("pending"),
+}));
+
+export type UsageEvent = typeof UsageEvent.$inferSelect;