Zespan is an AI agent observability and engineering platform. It traces every agent decision, tool call, handoff, and delegation in production. It also provides prompt versioning, built-in LLM-as-judge evaluations, guardrails, cost optimization, and an AI ops assistant called ZespanPilot.

How do I instrument my AI agent with Zespan?

Zespan requires 2 lines of code. Import zespan and call zespan.init({ apiKey: process.env.LT_KEY }). This auto-patches OpenAI, Anthropic, Gemini, Bedrock, and Mistral. For framework-level tracing, add one handler: ZespanCallbackHandler for LangChain, ZespanCrewAIListener for CrewAI, or ZespanADKHandler for Google ADK.

Does Zespan support prompt versioning?

Yes. Zespan includes prompt management with versioning, a playground for iteration, and A/B testing to compare prompt versions against each other in production.

What evaluations does Zespan support?

Zespan ships 12 built-in LLM-as-judge evaluation templates including faithfulness, relevance, toxicity, groundedness, and more. Evaluations run automatically on every trace with no custom scoring functions required.

How does Zespan compare to Langfuse?

Zespan is agent-native: every span carries agent identity, delegations are first-class trace events, and an agent map is built automatically. Langfuse was built for LLM pipelines and extended to agents later. Zespan also ships 12 built-in eval templates (Langfuse has none), includes an AI cost optimizer, and ZespanPilot for AI ops. Langfuse has open-source self-hosting; Zespan does not.

What is the free tier for Zespan?

The free tier includes 10,000 traces per month, 14-day retention, 2 projects, and 1 seat. No credit card required.

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AI Agent Observability
Guides & Tutorials

Deep dives on observability, cost optimization, and production engineering for teams building AI agents.

observabilityLangfuse

5 Best Langfuse Alternatives in 2026 (Ranked & Compared)

Langfuse self-hosting costs $200–800/mo in ClickHouse infra and has no built-in evals. We ranked the top 5 alternatives on pricing, agent support, and eval capabilities — with a clear winner for agent teams.

Jun 12, 2026·8 min read

observabilitycomparison

Best AI Agent Observability Tools in 2026: Zespan vs Langfuse vs LangSmith vs Helicone

The top AI agent observability tools compared: Zespan, Langfuse, LangSmith, and Helicone. Feature tables, pricing, and how to pick the right tool.

May 15, 2026·15 min read

observabilityalternatives

Helicone Alternatives in 2026: Best Options for AI Agent Observability

Top Helicone alternatives for AI agent observability in 2026. Agent support, eval capabilities, pricing, and proxy-free architectures compared.

May 8, 2026·13 min read

Google ADKGemini

Google ADK Observability: Monitor Gemini Agents in Production

Monitor Google ADK agents in production: delegation traces, Gemini model cost attribution, built-in evals. Zespan auto-patches Gemini API in two lines.

Apr 29, 2026·9 min read

CrewAItutorial

CrewAI Observability: How to Monitor Crews in Production

Full observability for CrewAI crews in production: traces per agent, delegation visibility, cost per task, and eval templates. 3-line setup with Zespan.

Apr 16, 2026·10 min read

OpenAItutorial

How to Monitor OpenAI Agents SDK in Production (2026 Guide)

Monitor OpenAI Agents SDK in production with Zespan: agentic traces, multi-agent handoff spans, cost alerts, and ZespanPilot. Auto-instrumented, no config.

Apr 8, 2026·10 min read

observabilityLangSmith

LangSmith Alternatives in 2026: Observability Tools for Teams Beyond LangChain

Evaluating LangSmith alternatives for AI agent observability? We compare Zespan, Langfuse, Helicone, and Braintrust on features, pricing, and multi-framework support.

Mar 27, 2026·8 min read

observabilitycomparison

LangSmith vs Langfuse vs Zespan: Which Agent Observability Tool Is Right for You?

A direct comparison of LangSmith, Langfuse, and Zespan for AI agent observability in 2026. Features, pricing, setup time, and which tool wins for production agent teams.

Mar 10, 2026·10 min read

LangChaintutorial

How to Monitor LangChain Agents in Production (2026 Guide)

Monitor LangChain agents in production with Zespan: agentic traces, delegation spans, cost alerts, and ZespanPilot. One callback handler to start.

Feb 25, 2026·8 min read

observabilityagents

What is AI Agent Observability? A Practical Guide for Engineering Teams

AI agent observability is not LLM monitoring. This guide explains the difference, what agent observability actually covers, and what to look for in a tool.

Feb 11, 2026·8 min read

AI Agent ObservabilityGuides & Tutorials