--- title: "Finding Slow Tool Calls in Vercel AI SDK v7 Telemetry" description: "When an agent takes ten seconds to respond, you need to know why. I used the new OpenTelemetry support in Vercel AI SDK v7 to track down a slow API call." image: "https://foundrysoft.co/api/og?type=article&title=Finding+Slow+Tool+Calls+in+Vercel+AI+SDK+v7+Telemetry&cat=AI+Engineering&rt=6+min+read&au=Varun+Raj+Manoharan&dt=2026-07-05" url: "https://foundrysoft.co/blog/vercel-ai-sdk-v7-telemetry-tracing" --- AI Engineering 2026-07-05 6 min read # Finding Slow Tool Calls in Vercel AI SDK v7 Telemetry When an agent takes ten seconds to respond, you need to know why. I used the new OpenTelemetry support in Vercel AI SDK v7 to track down a slow API call. ![Varun Raj Manoharan](https://foundrysoft.co/images/about/founder.webp) Varun Raj Manoharan Vercel AI SDK v7 Observability OpenTelemetry A lot of AI demos look incredibly fast until you run them in production. My weather-checking agent worked perfectly locally, but users complained it was freezing for ten seconds before typing a response. Before Vercel AI SDK v7, debugging latency meant littering my code with `console.time()`. The new `@ai-sdk/otel` package fixes this by hooking directly into Node.js tracing channels. ### Wiring up OpenTelemetry You have to configure an OpenTelemetry provider first. I exported my traces to a local Jaeger instance to visualize them. The SDK handles the rest automatically once you import the instrumentation module. TypeScript Copy ```typescript // instrumentation.ts import { registerOTel } from '@vercel/otel'; import { AISDKExporter } from '@ai-sdk/otel'; export function register() { registerOTel({ serviceName: 'weather-agent', traceExporter: new AISDKExporter(), }); } ``` TypeScript Copy ```typescript // agent.ts import { streamText } from 'ai'; import { openai } from '@ai-sdk/openai'; import { z } from 'zod'; export async function POST(req: Request) { return streamText({ model: openai('gpt-4o'), prompt: 'What is the weather in London?', tools: { getWeather: { description: 'Get current weather', parameters: z.object({ city: z.string() }), execute: async ({ city }) => { // This API call was the culprit const res = await fetch(`https://api.slow-weather.com/v1/${city}`); return res.json(); }, }, }, }); } ``` ### Reading the Traces When I checked the Jaeger dashboard, the problem was obvious. The trace showed the initial LLM call took 800 milliseconds. Then there was a massive eight-second block labeled `tool-execution: getWeather`. The final LLM call to format the response took another 600 milliseconds. The model was not slow. The external weather API I was using had terrible latency. The v7 observability features give you a granular breakdown of every step: how long the model thought, how long the tool ran, and how long the stream took to close. If you are building agents that rely on third-party APIs, this level of tracing is not optional. You have to know what is actually slowing you down. #### Related reading [Teaching an Agent Our Client Reporting Playbook with Vercel AI SDK v7 Skills Our monthly client reports followed a 40-line prompt nobody dared touch. I moved the whole playbook into an uploaded skill using the new uploadSkill API in Vercel AI SDK v7. Vercel AI SDK v7 ](https://foundrysoft.co/blog/vercel-ai-sdk-v7-agent-skills)[Building a Realtime Voice Support Agent with Vercel AI SDK v7 Voice agents used to mean marrying one provider's WebSocket event format. I used the new experimental realtime API in Vercel AI SDK v7 to build an order-status voice agent I can move between providers. Vercel AI SDK v7 ](https://foundrysoft.co/blog/vercel-ai-sdk-v7-realtime-voice-agent)[Letting an Agent Run Shell Commands Safely with Vercel AI SDK v7 Sandboxes I built a dependency-audit agent that runs npm commands on real projects. The new experimental sandbox support in Vercel AI SDK v7 is what made me comfortable shipping it. Vercel AI SDK v7 ](https://foundrysoft.co/blog/vercel-ai-sdk-v7-sandboxed-command-execution) #### Next Article [ The ROI of AI in 2026: Stop Building Demos ](https://foundrysoft.co/blog/roi-of-ai-2026-beyond-hype) Available for new projects ## Let's build something great. Have a project in mind? We are an elite software and AI development studio ready to bring your ideas to production. Let's talk about your roadmap. Start a Project [See our work](https://foundrysoft.co/work) ```json { "@context": "https://schema.org", "@type": "Organization", "name": "FoundrySoft", "url": "https://foundrysoft.co", "logo": "https://foundrysoft.co/logo.svg", "description": "FoundrySoft builds production-grade software and AI systems for US companies, from an India-based team of senior engineers.", "sameAs": [ "https://github.com/foundrysofthq", "https://www.linkedin.com/company/foundrysoft", "https://www.instagram.com/foundrysoft/" ] } ``` ```json { "@context": "https://schema.org", "@type": "WebSite", "name": "FoundrySoft", "url": "https://foundrysoft.co" } ``` ```json { "@context": "https://schema.org", "@type": "TechArticle", "headline": "Finding Slow Tool Calls in Vercel AI SDK v7 Telemetry", "description": "When an agent takes ten seconds to respond, you need to know why. I used the new OpenTelemetry support in Vercel AI SDK v7 to track down a slow API call.", "url": "https://foundrysoft.co/blog/vercel-ai-sdk-v7-telemetry-tracing", "mainEntityOfPage": "https://foundrysoft.co/blog/vercel-ai-sdk-v7-telemetry-tracing", "image": [ "https://foundrysoft.co/images/blog/vercel-ai-sdk-v7-telemetry.jpg" ], "datePublished": "2026-07-05", "dateModified": "2026-07-05", "keywords": "Vercel, AI, SDK v7, Observability, OpenTelemetry", "author": { "@type": "Person", "name": "Varun Raj Manoharan" }, "publisher": { "@type": "Organization", "name": "FoundrySoft", "logo": { "@type": "ImageObject", "url": "https://foundrysoft.co/logo.svg" } } } ``` ```json { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "https://foundrysoft.co/" }, { "@type": "ListItem", "position": 2, "name": "Blog", "item": "https://foundrysoft.co/blog" }, { "@type": "ListItem", "position": 3, "name": "Finding Slow Tool Calls in Vercel AI SDK v7 Telemetry", "item": "https://foundrysoft.co/blog/vercel-ai-sdk-v7-telemetry-tracing" } ] } ```