Culpa vs Traceloop

These two barely overlap, and saying so is more useful than manufacturing a fight. Traceloop is about quality: faithfulness, relevance and safety checks on real traffic, drift detection, and custom evaluators trained on your own examples. Nothing in its published feature set claims cost tracking, and its pricing page meters SPANS rather than dollars. Its FAQ defines a span as every call to an LLM and every call to a vector database, which is the detail worth pausing on. A retrieval request spends one model call and several vector queries, so a Traceloop meter climbs with retrieval fan-out while a provider bill climbs with tokens. Those are two curves and neither predicts the other. Traceloop was acquired by ServiceNow in March 2026 and says it will continue to sell the Traceloop functionality, so this is a comparison rather than a migration. The reason to run both is that a good answer which loses money is still a problem, and neither tool sees the other half.

• You know your evaluation scores and you can't name what a passing answer costs to produce.
• Your observability bill grew when you added retrieval, and your model bill didn't move.
• A quality regression and a cost regression look identical on your dashboards, which is to say invisible.
• You can say which prompt version scores best and not which one earns most.
• Retention on your free tier is measured in hours and nobody chose that number.

1. Count the spans one typical request produces, model calls and vector queries together.
2. Multiply that by monthly requests and compare it to the tier you're on.
3. Ask your evals tool what your best-scoring prompt version costs per call.
4. Check your retention in hours, then ask which cost question needs more than that.
5. Whatever goes unanswered is the gap, and the gap is the whole comparison.

Traceloop's free tier publishes 50,000 spans a month, and its FAQ counts every model call and every vector database call as a span. Take a retrieval request that makes 1 model call and 5 vector queries, so 6 spans, and price the same traffic on Claude Haiku 4.5 at $1.00 and $5.00 per million from the price book, effective 2026-07-02. Request shape is modelled. The rates and the allowance are published.

$37.50 of provider spend exhausts a 50,000-span allowance. Drop the retrieval step and the same $37.50 uses a sixth of it. The meter tracks your architecture rather than your bill, which is exactly why a span count can't answer a spend question.

Traceloop is the clearest case in this cluster of a tool Culpa sits beside rather than replaces, and the honest comparison says so. It self-hosts, including air-gapped, so privacy separates nothing here. It publishes SOC 2 and HIPAA compliance. OpenLLMetry is Apache-2.0 and feeds 25 or more platforms, so there isn't even a capture fight. What Traceloop never claims is a price. It meters spans rather than dollars and it holds no revenue, so it can't tell you that your best-scoring prompt version is also your least profitable one. Culpa prices each call from a versioned price book, carries what the customer pays you, and forecasts next month with a range. Run the evaluator for whether the answer was right and the ledger for whether it was worth producing.

• Batch Processing Cost Optimization: 50%, and How to Lose It
• Culpa vs LangSmith: Both Run in Your VPC, Only One Holds Revenue
• Culpa vs Polarity: One Changes the Bill, One Reads It
• Culpa vs Raindrop: Why It Broke and What It Cost