Claude Mythos 5.2
- Family
- Claude Mythos
- Released
- 2026-11-09
- Context
- 1M
- Max output
- 128K
- Architecture
- Decoder Only
- Knowledge cutoff
- 2026-06
- Specialization
- general
- Openness
- Proprietary
- License
- ProprietaryRestricted
- Weights
- Not released
- Code
- Unknown
- Training
- Pretrained
Restricted · Anthropic · cache read $0.200
About
Claude Mythos 5.2 is Anthropic's restricted Mythos-class model, released November 9, 2026. It is the same underlying model as Claude Fable 5.2 without the cybersecurity and biology safeguards. Access is restricted to organizations verified through Anthropic's Life Sciences and Cyber Verification Programs. Claude API id claude-mythos-5-2. 1M-token context, 128K max output, adaptive thinking always on (default effort high), text and image input to text output. Knowledge cutoff June 2026. For verified organizations, Anthropic documents model IDs for the Claude API, Amazon Bedrock, Claude Models on Google Cloud (Google-managed and Anthropic-managed), Microsoft Foundry and Claude Platform on AWS.
Providers(2)
Compare all 2Compare API pricing across 2 tracked provider routes for input and output tokens, batch, and cached reads when available.
| Provider | Input / 1M | Output / 1M | Batch in / out | Cache | Route |
|---|---|---|---|---|---|
| Anthropic | $8.00 | $40.00 | $4.00 / $20.00 | read $0.200 / 5m $10.00 / 1h $16.00 | RestrictedServerless |
| AWS Bedrock | - | - | - | - | RestrictedServerlessPartial |
Available via routers & gateways(15)
LiteLLM
GatewayOpen-source Python SDK and proxy server that unifies 100+ LLM APIs behind a single OpenAI-compatible interface, with load balancing, cost tracking, and configurable failover.
OpenRouter
HybridUnified hybrid gateway to 500+ models from 80+ providers via a single OpenAI-compatible API, with an optional Auto Router that selects a model per prompt from market spend data.
Portkey
GatewayProduction AI gateway routing to 1,600+ LLMs with failover, load balancing, caching, and guardrails; MIT-licensed open-source core is self-hostable. Now part of Palo Alto Networks as Prisma AIRS AI Gateway.
AIRouter
RouterCommercial LLM router (branded "AI Router" on its site) that picks the best model per request via a Decision API or an OpenAI-compatible Chat Completions endpoint, with a private selection mode that routes on anonymized patterns; sold as BYOK subscription plans priced by routed tokens.
Amazon Bedrock Intelligent Prompt Routing
RouterAWS Bedrock's native prompt router that predicts each model's performance per request and routes between two models of the same family (Anthropic Claude, Meta Llama or Amazon Nova).
Helicone
GatewayObservability-first AI gateway with routing, caching, rate limiting, and request tracing; Apache-2.0 open-source platform with a managed hosted tier for logging and analytics.
Capabilities
Benchmark peer barsfor Coding
No task-mapped benchmark peers are available for this model yet.
Benchmark scores(2)
| Benchmark | Score | Version | Evaluation | Source |
|---|---|---|---|---|
| 70.5 | Terminal-Bench 4.0Observed 2026-11-09 | Configuration: claude-mythos-5-2 (Claude Code --bare, max thinking, no safeguards) Harness: Claude Code --bare mode Evaluator: Anthropic Confidence: self-reported Notes: Anthropic self-reported (lab-published). System card, retrieved 2026-11-09. Does not move /best rankings (self-reported / raon rule). System card §8.5: 70.5% evaluated without safeguards; 660 trials, SE ±1.8 points. Claude Code --bare, max thinking. Separate from the Fable 5.2 safeguards-on 67.6% row. | ||
| 75.3 | Terminal-Bench-Science 0.1Observed 2026-11-09 | Configuration: claude-mythos-5-2 (Claude Code --bare, max thinking, no safeguards) Harness: Claude Code --bare mode, no internet Evaluator: Anthropic Confidence: self-reported Notes: Anthropic self-reported (lab-published). System card + launch table, retrieved 2026-11-09. Does not move /best rankings (self-reported / raon rule). System card §8.6 and launch table (Mythos 5.2 parenthetical): 75.3% without the Fable safeguards. Same 70-task, 10-trial setup. Separate from the Fable 5.2 74.6% row. |
Migration checks
No linked migration route is available for this model yet.
API versions
claude-mythos-5-2Rankings & picks(2)
Restricted · Anthropic · cache read $0.200