PromptLayer

PromptLayer

PromptLayer by Mosaic provides observability for LLM apps, tracing requests, monitoring token usage and cost, and debugging multi-step AI workflows from a single dashboard.

What is PromptLayer?

PromptLayer is an observability platform for LLM applications, built by Mosaic. It gives you a single timeline to trace every request your AI system makes—including prompts, responses, retries, tool calls, token usage, latency, and cost. You inspect the full execution waterfall without manually defining spans. It’s designed to help developers understand, debug, and optimize AI workflows in production.

Application scenarios

  • Debugging AI failures

    Identify silent retry storms, stalled tool calls, and cost spikes that standard monitoring misses.

  • Multi-step agent workflows

    Follow end-to-end execution across agents, tools, and providers with nested spans and sub-agents.

  • Cost tracking and optimization

    Monitor token usage and spend by model, provider, project, or individual request.

  • Performance monitoring

    View p50/p95 latency alongside cost to catch regressions before they hit your invoice.

  • Production incident response

    Replay specific traces and create alerts for failing requests or unexpected behavior.

Core Features

  • Traces

    Inspect prompts, responses, retries, tool calls, latency, token usage, and failures in one timeline. Filter by tag, user, model, or status. 14-day retention with 4ms overhead via async batching.

  • Workflow tracing

    Follow multi-step executions across agents, tools, and providers. Parent and child spans are ordered, showing the code path at a glance.

  • Cost breakdown

    Track spend by model, provider, project, or request. See p50/p95 latency next to cost so regressions don’t surprise you on the invoice.

  • Waterfall graph

    Visualize the full execution timeline with duration, cost, and span relationships—LLM calls, tool calls, and root spans.

  • Replay and alerts

    Replay individual traces and create alerts for specific conditions (e.g., failures, cost spikes).

  • Provider-agnostic instrumentation

    Works with any LLM provider or orchestration framework. Create traces and spans in a few lines of code.

  • Raw spans and logs

    Access raw span data and logs for deep debugging, including status, model calls, and timestamps.

Target users

PromptLayer is built for AI engineers, ML ops teams, and developers building production LLM applications. It’s especially useful for teams running multi-step agent workflows, using multiple providers (e.g., GPT-4o, Claude 3.5), or needing to track cost and performance across many requests.

How to use PromptLayer?

Start by signing up for free at promptlayer.app. Install the JavaScript SDK (@promptlayer/js) and instrument your workflow with a few lines of code. Create traces and spans to capture every provider call. Then view the complete execution waterfall in the PromptLayer dashboard—filter by tag, user, model, or status, and replay or set alerts on specific traces.

Pricing and free trial

The website text does not include any pricing details or free trial tiers. You’ll need to visit promptlayer.app for current pricing information.

Effect review

PromptLayer fills a clear gap in the LLM ops space: it shows you what actually happens inside your AI system, not just what your app logs. The waterfall graph and cost-per-request tracking are practical for debugging production issues like silent retry storms or cost spikes. The low overhead (4ms) and provider-agnostic design make it easy to add to existing stacks. While the product is still in beta and lacks detailed pricing, the feature set already looks solid for teams that need observability beyond basic logging.

Frequently Asked Questions

What is PromptLayer?
PromptLayer is an observability platform for LLM applications, providing request tracing, token usage and cost monitoring, and debugging for multi-step AI workflows from a single dashboard.
How does PromptLayer help debug AI workflows?
It traces each request in multi-step workflows, allowing you to inspect inputs, outputs, and intermediate steps to identify issues and optimize performance.
Can PromptLayer track token usage and costs?
Yes, it monitors token consumption and associated costs across all LLM calls, helping you manage budgets and optimize resource usage.
Is PromptLayer compatible with any LLM provider?
PromptLayer is designed to work with major LLM providers like OpenAI, Anthropic, and others, supporting integration via SDKs or API wrappers.
Does PromptLayer require code changes to integrate?
Minimal code changes are needed; you can wrap existing LLM calls with PromptLayer's SDK or use middleware to automatically log requests.
Is PromptLayer suitable for production environments?
Yes, it is built for production use, offering real-time monitoring, scalable logging, and secure data handling for enterprise applications.

PromptLayer - AI Tool Detail

PromptLayer by Mosaic provides observability for LLM apps, tracing requests, monitoring token usage and cost, and debugging multi-step AI workflows from a single dashboard.

Category:Prompt tool

Visit Link:https://promptlayer.app/

Tags:LLM observability、token cost tracking、prompt debugging、AI workflow monitoring、Mosaic