Best AI Agent Observability with a Free Plan or Free Trial

What is Langfuse?

Langfuse is an open-source LLM engineering platform for tracing, evaluation, prompt management, and metrics. It provides detailed traces of LLM application executions — capturing every LLM call, tool use, retrieval step, and agent action — and links traces to user sessions for production ...

What is LangSmith?

LangSmith is the LLMOps observability and evaluation platform built by LangChain for teams developing production LLM applications. It provides tracing, debugging, and evaluation for any LLM application — not just LangChain ones. Developers use LangSmith to trace every LLM call and tool ...

What is Arize AI?

Arize AI is a revolutionary Machine Learning Observability Platform to quickly identify and address model and data issues. With a comprehensive analytics suite and no restrictions on model framework, platform, or environment, Arize ensures companies can monitor the performance of their products ...

What is AgentOps?

AgentOps records what an agent did on every run and lets an engineer rewind through it afterwards. Each model call, each action the agent took and each handoff between agents is captured as an event with its input, its output and its cost, so a run that went wrong can be opened and read back in ...

What is Laminar?

Laminar is an Apache 2.0 agent observability platform that records every run and then groups the failures it finds across all of them. Laminar Signals reads each run, extracts the task the agent was given, and reports the distribution of behaviours and failure modes rather than one trace at a ...

What is Pydantic Logfire?

Pydantic Logfire records agent runs as OpenTelemetry spans and keeps them beside the traces from the rest of the application, so an agent step and the database query it triggered sit in the same timeline. It reads instrumentation from 26 or more agent frameworks, and because the query language ...

What is Future AGI?

Future AGI runs agents against realistic multi-turn conversations, edge cases and adversarial inputs at volume, then scores what each run did. The interface is built around the agent graph: nodes for each step, the path a run actually took, pass and fail counts per flow, and latency measured at ...

What is OpenLIT?

OpenLIT is an open-source platform for watching the whole harness an agent runs inside: the agent framework, the models it calls, the MCP servers it reaches, the vector databases it reads and the GPUs underneath. Everything is emitted as OpenTelemetry, so the same traces can be read in OpenLIT ...

What is Judgment Labs?

Judgment is built for agents whose runs are long rather than short, where a single task can span hundreds of steps and the stored trace runs to a very large amount of text. Storage and indexing are shaped around that, so a billion tokens of agent data stay searchable. Background agents read the ...

What is Scorecard?

Scorecard runs an agent through large numbers of realistic scenarios and returns scores in minutes, so a prompt, model or logic change is judged on measured results rather than a few manual checks. Test sets are managed in the platform and prompts can be edited and compared in a playground, ...

What is Datadog Agent Observability?

Datadog Agent Observability traces every step of an agent in production with span-level inputs, outputs and metadata across prompts, retrieval, the actions the agent takes and the decisions it makes, then correlates that with the backend services, infrastructure and real user sessions already ...

What is Braintrust (AI Observability)?

Braintrust is an evaluation and observability platform for teams building production LLM applications and agents. It lets engineers log and trace LLM calls with latency, token, and cost metrics, run structured evals against datasets to score output quality, and replay logged production traces ...