Claude Mythos Preview
Deprecated invitation-only research-preview model for Project Glasswing defensive-cybersecurity work; still reachable for invited customers (including on Amazon Bedrock) but migrate to Claude Mythos 5/5.1.
Data checked 2026-09-06
Anthropic
deprecated
claude-mythos-preview
- Context window
- 1M tokens in
- Max output
- —
- Input
- $25.00 per 1M tokens
- Output
- $125.00 per 1M tokens
- Blended
- $50.00 3:1 in:out
- Licence
- proprietary
A What it is for
No price, context window or output limit is published on any official Anthropic page - all numeric fields are recorded as unknown rather than guessed. It runs no safety classifiers and rejects non-default temperature/top_p/top_k.
At a three-to-one input-to-output ratio, Claude Mythos Preview costs $50.00 per million tokens blended. A workload of one million input and 330,000 output tokens per day would run about $1987.50 per month at list price, before caching or batch discounts.
B Capabilities
| Input modalities | text, image |
|---|---|
| Output modalities | text |
C Others from Anthropic
| Model | Context | Max out | In $/M | Out $/M | Blended | Status |
|---|---|---|---|---|---|---|
Claude Fable 5.1
claude-fable-5-1
|
1M | 128K | $10.00 | $50.00 | $20.00 | ga |
Claude Mythos 5.1
claude-mythos-5-1
|
1M | 128K | $10.00 | $50.00 | $20.00 | preview |
Claude Fable 5
claude-fable-5
|
1M | 128K | $10.00 | $50.00 | $20.00 | ga |
Claude Mythos 5
claude-mythos-5
|
1M | 128K | $10.00 | $50.00 | $20.00 | preview |
Claude Opus 5
claude-opus-5
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.8
claude-opus-4-8
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.7
claude-opus-4-7
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.6
claude-opus-4-6
|
1M | 128K | $5.00 | $25.00 | $10.00 | ga |
Claude Opus 4.5
claude-opus-4-5-20251101
|
200K | 64K | $5.00 | $25.00 | $10.00 | ga |
Claude Sonnet 5
claude-sonnet-5
|
1M | 128K | $2.00 | $10.00 | $4.00 | ga |
Claude Sonnet 4.6
claude-sonnet-4-6
|
1M | 128K | $3.00 | $15.00 | $6.00 | ga |
Claude Sonnet 4.5
claude-sonnet-4-5-20250929
|
200K | 64K | $3.00 | $15.00 | $6.00 | ga |
How this model is billed. Claude Mythos Preview does have a published per-token rate, but it is NOT on the platform.claude.com pricing table. The pricing table lists only 'Claude Mythos 5' and 'Claude Mythos 5.1' (both $10/$50 per MTok, marked limited availability and linking to anthropic.com/glasswing); 'Claude Mythos Preview' appears in that page only in two prose notes (the newer-tokenizer note and the long-context note
D Verify before you commit
Model pricing changes without notice and this page is a snapshot. Confirm against the vendor's own page before you build a budget on it.
Source: anthropic.com · checked 2026-09-06 · Anthropic pricing · API docs