The Short Answer
LangSmith is an observability and evaluation platform — it helps you see what your agent did, trace execution paths, and run evaluations. Kayba is a learning layer — it analyzes what your agent did and automatically improves how it behaves next time.
LangSmith tells you what failed. Kayba teaches your agent not to fail again.
They solve different problems and work well together: use LangSmith to observe, use Kayba to learn and improve.
What Each Tool Does
LangSmith
LangSmith, built by the LangChain team, provides:
- Tracing: Visualize every step of your agent's execution (LLM calls, tool use, retrieval)
- Evaluation: Run automated evals against datasets, compare prompt versions
- Monitoring: Track latency, cost, and error rates in production
- Datasets: Create and manage test datasets for regression testing
- Playground: Test prompt variations interactively
It's the industry standard for understanding what your agent is doing. The traces are detailed, the UI is polished, and the LangChain ecosystem integration is seamless.
Kayba
Kayba provides:
- Trace analysis: The Recursive Reflector programmatically analyzes agent execution traces via REPL-based code execution — not just visualizing them, but extracting actionable insights
- Skill extraction: Failures and successes are distilled into atomic, reusable skills with helpful/harmful counters
- Skillbook: A persistent, transparent collection of everything the agent has learned — organized, auditable, with provenance tracking
- Prompt generation: Approved skills are compiled into optimized system prompts
- Continuous learning: Delta updates refine the Skillbook incrementally over time
The Key Difference
The distinction is observe vs. act.
| Capability | LangSmith | Kayba |
|---|---|---|
| See what happened | Detailed traces, execution visualization | Trace analysis with pattern extraction |
| Understand why it failed | Manual inspection of traces | Automated failure analysis via Recursive Reflector |
| Fix the behavior | You manually edit prompts based on what you observed | Skills extracted automatically, prompts generated from Skillbook |
| Remember the fix | In your head, docs, or prompt changelog | Skillbook with provenance — every skill links to its source trace |
| Prevent recurrence | Run evals to catch regressions | Continuous learning — the Skillbook grows with each analysis cycle |
With LangSmith alone, the workflow is:
- Agent fails → 2. Check LangSmith traces → 3. Spot the pattern → 4. Manually edit system prompt → 5. Hope it doesn't break something else → 6. Repeat
With Kayba added:
- Agent fails → 2. Kayba analyzes traces → 3. Skills extracted automatically → 4. Review and approve → 5. New prompt generated → 6. Agent improves
Comparison
| Dimension | LangSmith | Kayba |
|---|---|---|
| Primary function | Observability & evaluation | Learning & prompt improvement |
| Trace handling | Visualize and search | Analyze and extract skills |
| Framework dependency | Strongest with LangChain (works with others via SDK) | Framework-agnostic (any trace format) |
| Eval approach | Dataset-based automated evals | Trace-based skill extraction with helpful/harmful tracking |
| Output | Dashboards, metrics, trace views | Skillbook + generated system prompts |
| Learning mechanism | None (observability only) | Recursive Reflector + Skillbook + delta updates |
| Open source | Partially (tracing client is OSS, platform is proprietary) | Fully open-source (MIT, 2k+ stars) |
| Pricing | Free tier + usage-based (from $39/seat/month) | Free (OSS) / $29/month (hosted dashboard) |
Using Them Together
LangSmith and Kayba are complementary. A practical setup:
- LangSmith traces every agent execution in production — you get monitoring, alerting, and the ability to inspect individual conversations
- Export traces from LangSmith (or collect them directly from your agent)
- Kayba analyzes those traces, extracts skills, and generates improved prompts
- LangSmith evals verify that the new prompts actually improve agent performance before deployment
LangSmith gives you visibility. Kayba gives you improvement. Together, you have a closed loop: observe → learn → improve → verify.
When to Use LangSmith Alone
LangSmith is sufficient if:
- You mainly need production monitoring (latency, costs, error rates)
- Your team has bandwidth to manually review traces and edit prompts
- You're in early development and need to debug agent behavior interactively
- You're deeply invested in the LangChain ecosystem and want tight integration
When to Add Kayba
Add Kayba when:
- You're tired of manually reading traces to find failure patterns
- Your agent is in production with enough volume that manual review doesn't scale
- You want a systematic record of what the agent has learned (not scattered prompt edits)
- You need framework flexibility — Kayba works with any agent, not just LangChain
- You want the improvement step automated, not just the observation step
Getting Started
Kayba is open-source and analyzes traces from any source — including LangSmith exports.
pip install ace-framework
- Documentation — Setup guides and API reference
- GitHub — Source code and examples
- Dashboard — Hosted version with visual Skillbook management