Claude Mythos 5
Claude Mythos 5 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 3 tracked provider routes
Do not use it for
- Workloads where another current model has stronger sourced task evidence
- Family
- Claude Mythos
- Released
- 2026-06-09
- Context
- 1m
- Max output
- 128,000
- Architecture
- Decoder Only
- Specialization
- security
- Openness
- Proprietary
- License
- ProprietaryCommercial use with conditions
- Training
- pretrained
Cheapest of 3 routes · Anthropic
About
Anthropic's access-gated frontier model, available exclusively through Project Glasswing to approved cybersecurity defenders and biomedical research organizations. Shares the same underlying architecture as Claude Fable 5 but operates with safety classifiers lifted in specific domains: cybersecurity safeguards are removed for all Glasswing participants, while biology safeguards are additionally removed for approved biology-track participants. Succeeds Claude Mythos Preview with significantly reduced pricing ($10/$50 per MTok input/output vs. $25/$125 for Mythos Preview), a 1M-token context window, 128k max output tokens, adaptive thinking always on (raw chain of thought never returned), vision, tool use, structured outputs, and the effort parameter for controlling thinking depth. Extended thinking with manual budget_tokens is not supported. For general-availability access to Mythos-class capability, see Claude Fable 5.
Claude Mythos 5 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, AWS Bedrock, and GCP Vertex AI, with the cheapest tracked route listed at $10 input and $50 output per 1M tokens. Headline tracked benchmarks include Terminal-Bench 2.1 88.0 and Humanity's Last Exam 64.5.
Top use-case fit: coding, agents, and build tasks
Coding
Included by capability and metadata signals in the decision map.
RAG
Included by capability and metadata signals in the decision map.
Agents
Included by capability and metadata signals in the decision map.
Provider price ladder
Compare all 3Compare API pricing across 3 providers for input and output tokens, batch, and cached reads when available.
| Provider | Input / 1M | Output / 1M | Route |
|---|---|---|---|
| Anthropic | $10.00 | $50.00 | Serverless |
| AWS Bedrock | - | - | ServerlessPartial |
| GCP Vertex AI | - | - | ServerlessPartial |
Available via routers & gateways(15)
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.
Amazon Bedrock Intelligent Prompt Routing
RouterAWS Bedrock's native intelligent prompt router that routes prompts between Anthropic Claude model tiers (Haiku/Sonnet) based on predicted task complexity, with no extra per-routing charge.
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.
Kong AI Gateway
GatewayMulti-LLM AI gateway built on Kong Gateway 3.x, adding semantic routing, load balancing, guardrails, and MCP traffic analytics as plugins over Kong's existing API management platform.
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.
Martian
RouterAI-powered LLM router that analyzes each prompt in real-time to select the optimal model, targeting 20–97% cost reduction while maintaining quality; San Francisco startup reportedly nearing $1.3B valuation.
Capabilities
Benchmark peer barsfor Coding
No task-mapped benchmark peers are available for this model yet.
Benchmark scores(2)
| Benchmark | Score | Version | Source |
|---|---|---|---|
| Terminal-Bench 2.1 | 88.0 | Terminal-Bench 2.1 | https://www.anthropic.com/news/claude-fable-5-mythos-5 |
| Humanity's Last Exam | 64.5 | HLE (with tools) | https://www.anthropic.com/news/claude-fable-5-mythos-5 |
Migration checks
No linked migration route is available for this model yet.
Rankings & picks(2)
Comparison and alternatives
Browse all comparisons →Cheapest of 3 routes · Anthropic