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Laminar Lands 3M to Debug Long-Running AI Agents

The big picture: When an AI agent runs for 40 minutes and fails on its 201st decision, traditional logging tools become a liability. Searching through thousands of spans to find a single hallucination is a massive productivity drain. Laminar is building an open-source, Rust-based observability platform specifically designed to handle the massive context and duration of modern “long-running” agents.

Why it matters:

  • The Debugging Wall: Most tools only show what happened; Laminar allows developers to jump to the exact step where an agent failed, tweak the prompt, and rerun execution from that point with the full environment state (DOM, sandbox, memory) restored.
  • Token-Free Replay: By mocking prior LLM calls and replaying original responses, Laminar lets agents “walk” back to their failure state instantly without consuming additional tokens or time.
  • Natural Language Signals: Instead of manual filtering, developers can use natural language queries (e.g., “find where the agent gets stuck in a loop”) to cluster thousands of production traces into recognizable failure patterns.

How it works:

  • Auto-Instrumentation: A single line of code instruments the majority of AI frameworks, including Claude Agent SDK, LiteLLM, and Browser Use.
  • Reader Mode Tracing: Replaces the standard “tree of spans” with a clean, readable feed of an agent’s reasoning and actions, synchronized with full browser session recordings for UI agents.
  • Built-in SQL Engine: All trace data is accessible via a built-in SQL editor and API, allowing teams to bulk-create evaluation datasets directly from production logs.

The catch: Laminar is entering a hyper-competitive field alongside newly funded rivals like Respan and established players like LangSmith. While its “token-free debugger” and Rust-based speed are strong technical moats, the platform’s survival depends on becoming the default “open-source standard” before the major LLM providers bake these specialized debugging features directly into their own developer consoles.

Key Details

  • Funding: $3M (Seed)
  • Lead: Atlantic.vc
  • CEO: Robert Kim
  • Sector: AI Infrastructure / Observability

Martin Kassing, CEO of Upvest

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Bip Thelin, CEO of Noru

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