Example prompts
Things to ask your coding agent once OptBench is connected. The agent picks the tools; you don't need their names.
Start
- "Scan this repo with OptBench." Finds the LLM calls and sets up a use case for each, with metrics and test cases. In Claude Code you can also run
/mcp__optbench__scan_repo. - "Which LLM calls in this repo cost the most? Use OptBench's cost ranking." Free, no model calls.
Benchmark
- "Estimate a benchmark run for the invoice extraction use case." Free. Shows the models, cases and the cost.
- "Start that run." The agent asks you to confirm the cost first.
- "How is the run going? Which model does OptBench recommend?"
- "Add Qwen and DeepSeek to the finished run instead of starting over."
Test cases
- "Add the fixtures in tests/fixtures/support as test cases for the support chat use case."
- "Generate 20 more test cases for the summarizer."
- "Import last week's traces from PostHog as test cases." The agent checks your data rules first and shows a preview before importing.
- "Write the expected answers for the imported cases that have none."
Workflows
- "Before we launch, benchmark the new summarizer: write 3 cases with me, generate the rest up to 30, then estimate a pilot and the full run." See Benchmark before launch.
- "Add OptBench as a second OpenTelemetry exporter in this app. Read the ingest key from OPTBENCH_INGEST_KEY and keep our existing exporter." See Connect traces.
- "Refresh the support chat sample from PostHog and tell me how many requests are new." The agent shows the preview before importing.
- "Write gold for the imported support chat cases from the traces and our code. Checks only, no final answers." Free. See Write gold.
- "Estimate what it costs to have OptBench draft gold for the support chat cases that have none. Don't start it." Shows the cost; nothing runs until you confirm.
- "Is the last summarizer run a Decision or a Shortlist? What would it take to get a Decision?" For what comes after launch, see Monitor in production.
Keep it current
- "I changed the prompt in src/llm/summarize.ts. Check OptBench for drift."
- "Re-select the metrics for the support chat use case and show me the diff."
Settings
- "Which models may see our prompts under our model rules?"
- "Only use EU-hosted models for this project."