Rumors: Anthropic quietly testing Opus 5.5, possible surprise Tuesday launch

According to leaks aggregated by multiple bloggers and media outlets, Anthropic is secretly testing a new model under the codename claude-opus-5-5 (internally known as claude-wafer-eap), i.e. Claude Opus 5.5, which would skip 5.1/5.2 and launch directly — possibly as early as Tuesday. As of publication, Anthropic has not officially confirmed anything.

Confirmed

• No official information; everything in this cluster is third-party leaks, unverified by Anthropic

Unconfirmed

• Launch timing: @airesearch12 and @量子位 say Tuesday; @markk cites an X user lyraxana claiming next Monday or Tuesday, saying Anthropic internally labeled it "imminent" and partners were given only 24 hours of access
• Naming and version skip: @新智元 and @量子位 report a direct jump over 5.2 (or 5.1/5.2) to release Opus 5.5
• Pricing: rumored prices compiled by @xeophon are $4 per million input tokens, $20 per million output tokens, $5 cache write, and $0.2 cache read; commenters noted this would be a major win if true, since cache reads make up the bulk of real token spending. @量子位 says overall pricing is roughly 60% of OpenAI Astra; @新智元 mentions input dropping to 4 USD per million tokens
• Performance: @danielmac8 says it's rumored to outperform and undercut Google's Astra on price; @量子位 claims capabilities beat OpenAI's GPT-6 Sol/Astra; @新智元 cites beta testers highlighting standout problem-solving intuition, deep code refactoring, and long-horizon task performance

Why it matters

• If the pricing rumors hold, the ultra-low cache-read price would significantly cut costs for high-frequency usage, directly benefiting Claude-dependent developers
• A version-skipping release positioned against GPT-6 Astra would intensify head-to-head flagship competition among Anthropic, OpenAI, and Google — though before an official launch, naming, timing, and pricing should all await Anthropic's official announcement

2026-09-20 ~ 2026-09-21 · 6 related posts

• Leak: Anthropic stealth-testing Opus 5.5 as claude-wafer-eap, release tipped for Tuesday — airesearch12 · 2026-09-20
• [source] Leaked Claude Opus 5.5 Pricing Shows $0.20/Mtok Cache Read, Sparking Hype — xeophon · 2026-09-20
• Rumor: Anthropic's Opus 5.5 landing this week, said to beat Astra on price and quality — daniel_mac8 · 2026-09-21
• [source] Leaked Claude Opus 5.5 skips to testing with $4/M input tokens, undercutting Opus 5 by ~20% — 新智元 · 2026-09-21
• Leaked: Anthropic to skip versions and launch Claude Opus 5.5 this Tuesday, undercutting GPT-6 Astra — 量子位 · 2026-09-21
• [source] Leak: Anthropic Opus 5.5 may land Monday or Tuesday, with always-on adaptive thinking — mark_k · 2026-09-21