An Anthropic blog post by Michael Segner, dated 2026-09-24, about how Claude Code sessions changed between March and September 2026 and how Claude Opus 5.5 is priced and tuned for them.
Caveat: this is vendor marketing. Every number is Anthropic-reported, with no method, sample, or workload definition given; “typical workloads” is not defined. The post does not list absolute prices.1
Headline numbers
| Claim | Figure |
|---|---|
| Cost to run versus Opus 5, typical token-billed workloads | about 40% less |
| Input and output token price | 20% lower |
| Cached token read price | 60% lower |
| Input missing the cache | down more than 50% |
| Output speed versus Opus 5 | over 30% faster |
As reported in the post.1
Takeaways
- Sessions got longer and heavier on context, so cached reads now dominate agentic cost. See Claude Code session cost.
- Savings come from lower prices, fewer cache misses, and fewer turns. See Where the savings come from.
- Subagents now start from the parent’s cache. See Subagents.
- Watch cached reads with
/usage, pick the model at session start, and use a one-hour cache for long API sessions.1 See Keeping the cache warm.