Claude Mythos Preview
Claude Mythos Preview is worth evaluating for coding, rag, and agents when its provider route and context window match the workload.
Use it for
- Teams evaluating coding, rag, and agents
- Workloads that can use a 1m context window
- Buyers comparing 2 tracked provider routes
Do not use it for
- Workloads where another current model has stronger sourced task evidence
- Family
- Claude Mythos
- Released
- 2026-05-01
- Context
- 1m
- Architecture
- Decoder Only
- Knowledge cutoff
- 2025-12
- Specialization
- security
- Openness
- Proprietary
- License
- ProprietaryCommercial use: conditional
- Weights
- Not released
- Code
- Unknown
- Training
- Pretrained
Cheapest of 2 routes · Anthropic
About
Anthropic's cybersecurity-focused frontier model, offered as an invitation-only research preview under Project Glasswing. Succeeded by Claude Mythos 5 (API ID: claude-mythos-5) as of June 9, 2026. Anthropic has indicated that Claude Mythos Preview will be retired after Claude Mythos 5 becomes available; no formal retirement date was published as of 2026-06-09. For current access and the migration path, see the Anthropic migration guide.
Claude Mythos Preview is a proprietary model in the Claude Mythos family. The structured metadata tracks a 1m-token context window, multimodal input, reasoning, function calling, tool use, structured outputs, and code execution. This page tracks provider routes through Anthropic and Microsoft Foundry, with the cheapest tracked route listed at $25 input and $125 output per 1M tokens. Headline tracked benchmarks include SWE-bench Verified 93.9, τ-bench 89.2, and Google-Proof Q&A 94.6.
Top use-case fit: coding, agents, and build tasks
Coding
Q/$ D1 relevant benchmark in the decision map.
RAG
Included by capability and metadata signals in the decision map.
Agents
Q/$ D2 relevant benchmarks in the decision map.
Provider price ladder
Compare all 2Compare API pricing across 2 providers for input and output tokens, batch, and cached reads when available.
| Provider | Input / 1M | Output / 1M | Route |
|---|---|---|---|
| Anthropic | $25.00 | $125.00 | Serverless |
| Microsoft Foundry | - | - | ServerlessPartial |
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 400+ models from 60+ providers via a single OpenAI-compatible API, with optional auto-routing that selects the best model per prompt.
Portkey
GatewayProduction AI gateway routing to 1,600+ LLMs with failover, load balancing, semantic caching, and guardrails; Apache 2.0 core is fully self-hostable with the complete feature set.
AIRouter
RouterCommercial LLM router that analyzes incoming requests and routes to the optimal model for cost/quality/latency via a drop-in OpenAI-compatible API, with a privacy-preserving embedding mode that avoids sending prompt content.
Azure AI Foundry Model Router
RouterMicrosoft Azure AI Foundry's native model router that uses a trained ML model to route each prompt in real time to the optimal Azure-hosted model, with Balanced/Cost/Quality mode selection and automatic failover.
Helicone
GatewayObservability-first AI gateway with routing, caching, rate limiting, and request tracing; Apache 2.0 open-source core with a managed hosted tier for logging and analytics.
Capabilities
Benchmark peer barsfor Coding
Benchmark scores(3)
| Benchmark | Score | Version | Source |
|---|---|---|---|
| SWE-bench Verified | 93.9 | SWE-bench Verified | https://anthropic.com/glasswing |
| τ-bench | 89.2 | τ-bench | https://benchlm.ai/benchmarks/tauBench |
| Google-Proof Q&A | 94.6 | diamond | https://epoch.ai/benchmarks/gpqa-diamond; https://intuitionlabs.ai/articles/gpqa-diamond-ai-benchmark |
Migration checks
No linked migration route is available for this model yet.
Rankings & picks(2)
Compare Claude Mythos Preview with other models
- Claude Mythos Preview vs Grok 41K
- Claude Mythos Preview vs GPT-5.5537
- Claude Mythos Preview vs DeepSeek V4 Pro360
- Claude Mythos Preview vs ByteDance Doubao Seed 2.0 Pro340
- Claude Mythos Preview vs Grok 4.3315
- Claude Mythos Preview vs ByteDance Doubao Seed 2.0 Code191
- Claude Mythos Preview vs GPT-5.5 Pro189
- Claude Mythos Preview vs DeepSeek V4 Flash166
Comparison and alternatives
Browse all comparisons →Show all 19 popular comparisonssorted by 7-day search impressions
Frequently asked questions
What is the context window of Claude Mythos Preview?
Claude Mythos Preview has a context window of 1m tokens.
How much does Claude Mythos Preview cost?
Claude Mythos Preview is available at $25.00/1M input tokens through Anthropic.
When was Claude Mythos Preview released?
Claude Mythos Preview was released on 2026-05-01.
Which providers offer Claude Mythos Preview?
Claude Mythos Preview is available from 2 providers: Anthropic, Microsoft Foundry.
What benchmarks has Claude Mythos Preview been tested on?
Claude Mythos Preview has been evaluated on 3 benchmarks, including SWE-bench Verified, τ-bench, Google-Proof Q&A.
Cheapest of 2 routes · Anthropic