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Foglamp

Foglamp is an observability layer for AI agents on the Vercel AI SDK. Track cost, latency, traces, eval scores, and alerts for production `generateText` and `streamText` calls.

Foglamp

Overview

Foglamp is an observability layer for AI agents on the Vercel AI SDK. It is designed to show the cost, latency, token usage, traces, eval scores, and alerts for each `generateText` and `streamText` call.

The product focuses on production agent workflows: instrument once, then inspect runs, score sampled traffic, and set alert rules when cost, error rate, latency, or quality drift. The source positions it as a way to understand what AI agents are doing in real time and to catch bad output before users do.

Features

Two-line SDK instrumentation

Wrap the model once and instrument every `generateText` and `streamText` call in two lines. The product is positioned as a lightweight observability layer for AI agent runs.

Agent-level tracing

Track per-agent spans, latency, and spend across the full call flow, including orchestrator and downstream agents. This helps teams see where time and cost accumulate in a workflow.

Production evals

Measure production quality with code checks and LLM judges on live traffic. Evals run on a 0–1 scale with pass thresholds, and the source notes checks such as valid JSON, no PII, tone, and groundedness.

Threshold alerts

Set threshold rules on cost, latency, error rate, and eval scores. Foglamp checks these rules every minute and can scope them to an agent, model, or project.

Cost intelligence

Attribute cost by model, agent, workflow, and individual customer using live provider pricing. The product says it uses real token usage and supports breakdowns that match billed usage more closely.

Trace-to-root-cause workflow

Jump from an alert or failed score directly to the traces behind it. The source also highlights waterfall-style traces with the exact prompt and response per span.

Use Cases

  • Debugging production agent behavior

    Track latency, cost, and trace data for each production agent run so teams can see what changed after a deploy and identify the exact model or step involved.

  • Cost monitoring and regression detection

    Monitor spend by model, agent, workflow, or customer and set daily or threshold-based limits to catch regressions before they show up on a bill.

  • Eval-driven QA for production traffic

    Score live traffic with code checks and LLM judges to measure pass rate, then trend quality over time for specific agents or workflows.

  • On-call alerting and incident triage

    Receive email or Slack alerts when cost, latency, error rate, or eval scores cross a threshold, then inspect linked traces to investigate the spike.

  • Agent chain inspection

    Review waterfall traces with exact prompts and responses per span to understand how an orchestrated agent chain produced an outcome.

Pros and Cons

Pros

  • Shows cost, latency, tokens, traces, evals, and alerts in one place for production agent traffic.
  • Uses real token usage and live provider pricing for cost attribution.
  • Supports both deterministic code checks and LLM judges for quality scoring.
  • Adds minute-by-minute alerting with email and Slack delivery.
  • Lets users drill from alerts or eval failures into the underlying trace.

Cons

  • The source only clearly documents the Vercel AI SDK integration, so support for other SDKs or platforms is not established here.
  • Some plans and limits are usage-based, so teams with high volume may need to compare spans, retention, and alert counts before adopting a plan.

FAQ

What does Foglamp integrate with?

Foglamp is built around the Vercel AI SDK and instruments `generateText` and `streamText` calls. The source does not describe other supported SDKs or frameworks.

Does Foglamp have a free plan?

The pricing page shows a Free plan, a Pro plan, and an Enterprise plan. Free includes 10,000 spans per month and 3 days of retention; Pro is $49 per month; Enterprise is custom pricing.

Can teams route alerts to existing channels?

Yes. The source says alerts can be scoped to an agent, model, or the whole project, and delivered to email and Slack.

How are evals used?

Foglamp scores sampled production traces on a 0–1 scale using code checks and LLM judges, and the source says you can sample a fixed rate or score everything.

Are there limitations to be aware of?

The source emphasizes real-time cost attribution, distributed traces, alerts, and evals for production agent runs, but it does not describe support for unrelated observability stacks or non-Vercel SDKs.

Quick Facts

Category
Developer Tool
Primary focus
AI agent observability
Platform
Built on the Vercel AI SDK
Key metrics
Cost, latency, tokens, distributed traces, evals, alerts
Pricing model
Free, Pro, and Enterprise plans
Source domain
foglamp.dev