Langfuse vs Harny
A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.
Langfuse compared with Harny
| Detail | L
Langfuse | 
Harny |
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| What it does | Open Source Agent Evals & Observability
| Agent harness infrastructure that gives AI agents memory for each user, connected accounts, action limits and an audit record.
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| Stage | Established
| Not given
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| Founded | Not given
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| Based in | DE
| CA
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| Pricing model | Freemium
| Freemium
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| Pricing | Not given
| Free: first 500 monthly-active end users per month, free forever. Paid: $0.30 per monthly-active end user above 500, billed monthly.
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| Key features | - Hierarchical traces capture every LLM call, tool invocation, and retrieval step
- LLM-as-a-judge, heuristic functions, or human review evaluations
- Prompt management with one-click deployments and rollbacks
- Playground to test prompts on real production inputs and compare models
- Experiments with test cases and side-by-side comparison
- Human annotation and collaborative human-in-the-loop workflows
- Cost and latency monitoring with dashboards and alerts
- REST APIs and Query SDK for data access
- Langfuse Assistant to automate the AI engineering loop
| - Timestamped memory ingestion with backdating capability
- Per-user data isolation and privacy scoping
- Ranked memory recall with dated evidence
- Connected accounts integration per user
- Long-running agent jobs with folder-level operations
- Configurable token ceiling per API call
- Enforced action limits on agent operations
- Complete action audit trail with hash chaining
- MCP server integration for Claude and other clients
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| What makes it different | - MIT licensed open source platform with no data lock-in
- Enterprise scale architecture handling billions of monthly events
- Works with any language and framework with no framework lock-in
- Async by default so tracing never blocks your application
| - Highest published BEAM benchmark score at 128K tokens: 85.1, compared to competing memory systems
- 98% fewer tokens required than raw tool output, making responses 4× cheaper
- Works with 20+ agent frameworks including LangChain, LangGraph and LlamaIndex
- First 500 monthly-active end users free forever
- Per-person billing model scales with user growth, not API calls
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| Free plan | Not given
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| Open source | Not given
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| Platforms | Not given
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| Public API | Not given
| Not given
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| Community votes | 0 | 0 |
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| DR (Domain Rating by Ahrefs) | 80 ▲ +1 (up) since last check | Not checked yet ● no change since last check |
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| Trust Flow (Majestic) | 35 | 0 |
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| Citation Flow (Majestic) | 54 | 0 |
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| Referring domains (Majestic) | 6114 | 1 |
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5 details filled in for both companies.
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