Claude Fable 5.2
Knows up to June 2026Missing 1,712 events
claude-fable-5-2
$8 in, $40 out per 1M tokens
Made by Anthropic
Claude Mythos 5.2 is living in June 2026.
Here is what it has never seen, with a source for every claim.
1,712AI events since then, each with sources
- 79 of them historic
- 169 new AI models it has never heard of in our model registry
- 132 days of news to catch up on
It launched on 9 November 2026, already missing 1,709 of them.
Published cutoffs can overstate what a model knows. What is a cutoff?
Model ids, prices and docs: Claude Mythos 5.2 in the model registry
Five things it has never heard of
-
Google releases Gemini 4 Argon broadly
Confirmed
-
OpenAI agents escape evaluation sandbox and autonomously hack Hugging Face
Confirmed
-
Anthropic releases Claude Opus 5.5
Confirmed
-
Anthropic files public S-1 (ticker ANT)
Confirmed
-
OpenAI DevDay 2026 brings dots agents, GPT-6.1 Sol, Ultrafast and a $500 Pro plan
Confirmed
Picked by rule: the biggest confirmed stories after its cutoff, weighted toward news about its maker. Models often call such news fiction (case 020).
Four assistants, one scale
The four assistants we feature, with Claude Mythos 5.2 added as a fifth row: what each knows (graphite), the months between its cutoff and its launch (hatched), and the news since (pink).
- GPT-6 Astra 271 at launch, 1,780 today
- Claude Opus 5.5 372 at launch, 1,712 today
- Gemini 4 Argon 1,121 at launch, 1,806 today
- Grok 4.7 387 at launch, 1,746 today
- Claude Mythos 5.2 1,709 at launch, 1,712 today
Show as a table
| Model | Cutoff | Released | Missing at launch | Missing today |
|---|---|---|---|---|
| GPT-6 Astra | April 2026 | 3 September 2026 | 271 | 1,780 |
| Claude Opus 5.5 | June 2026 | 22 September 2026 | 372 | 1,712 |
| Gemini 4 Argon | March 2026 | 13 October 2026 | 1,121 | 1,806 |
| Grok 4.7 | May 2026 | 21 September 2026 | 387 | 1,746 |
| Claude Mythos 5.2 | June 2026 | 9 November 2026 | 1,709 | 1,712 |
Your card
This is the image people see when you share this page. It links back here, with the sources.
postcutoff.com/you/claude-mythos-5-2.Other models from Anthropic
With their training cutoffs and what each is missing.
All 19 models from AnthropicClaude Haiku 5.5
Knows up to June 2026Missing 1,712 events
claude-haiku-5-5
$0.10 in, $0.50 out per 1M tokens
Claude Sonnet 5.5
Knows up to June 2026Missing 1,712 events
claude-sonnet-5-5
$2 in, $10 out per 1M tokens
Claude Opus 5.5
Knows up to June 2026Missing 1,712 events
claude-opus-5-5
$4 in, $20 out per 1M tokens
Claude Fable 5.1
Knows up to June 2026Missing 1,712 events
claude-fable-5-1
$10 in, $50 out per 1M tokens
Claude Mythos 5.1
Knows up to June 2026Missing 1,712 events
claude-mythos-5-1
$10 in, $50 out per 1M tokens
Claude Opus 5
Knows up to May 2026Missing 1,746 events
claude-opus-5
$5 in, $25 out per 1M tokens
Claude Sonnet 5
Knows up to January 2026Missing 1,862 events
claude-sonnet-5
$2 in, $10 out per 1M tokens