Release facts and lifecycle
- Release announced
- September 28, 2026
- Model ID
- claude-sonnet-5-5
- Announced access
- Claude API and supported AWS, Google Cloud and Microsoft platforms
- Latest lifecycle note
- Cache-read price update announced October 7, 2026
Original provider sources checked . These are source facts, not a benchmark of Flonno's deployment.
Open the live model record, benchmarks and release journal →Where to start
Replay complete coding and tool loops through the native Messages API. Track the patch, tests, retries and all reported usage. Benchmark evidence remains attached to the exact Radar artifact.
- Coding workflows
- Tool use
- Knowledge work
What to check before deployment
Use the exact Claude endpoint and current model documentation for limits and prices. Cache-read pricing changed on October 7, 2026; a launch-era estimate can be stale.
Confirm the exact model ID, checkpoint revision and endpoint in your test record. A base model name does not establish a provider's quantization, accepted inputs, context limit or current availability.
Measure useful results
Build a small evaluation from the workflow you already run. Define the expected answer before testing. Track correct results, formatting errors, retries, complete request time and reported input and output usage.
Count rejected answers and manual corrections. A low token rate can still produce a high cost per accepted result when the workflow needs retries or repair.
Estimate your token budget →Sources and scope
This page is an editorial evaluation guide, not a benchmark result or a claim that this model is served by Flonno.
Official model announcement ↗License / access: Provider service terms. Read the linked license or service terms for the full conditions. Original release and lifecycle sources checked 2026-10-10.