Compare cost between two models - Narev Docs

Model shopping fails when you change the prompt and the model at the same time. Fix the usage block first, then compare totals.

Set a fixed usage block

{
  "prompt_tokens": 450,
  "completion_tokens": 25
}

Price the baseline

curl -X POST 'https://api.narev.ai/v1/traces/cost' \
  -H 'Content-Type: application/json' \
  -d '{
    "model_id": "gpt-4",
    "provider_id": "openai",
    "usage": {
      "prompt_tokens": 450,
      "completion_tokens": 25
    }
  }'

Price the candidate

Repeat with the cheaper model and the provider that lists it. Search first when you do not know which host carries the model:

curl -G 'https://api.narev.ai/v1/prices/search' \
  --data-urlencode 'q=gpt-oss-20b'

Then call POST /v1/traces/cost with the same usage block.

Compare totals

Model	Provider	`cost_breakdown.total`
gpt-4	openai	baseline
gpt-oss-20b	llmgateway	candidate

If the candidate total is lower, pull live rates confirmed the savings before you switch.

Full case study

For accuracy and latency tradeoffs on a real routing workload, see Reduce LLM spend by switching models.