LLM
Claude Mythos 5
Restricted-access (dual-use) tier referenced via the Cyber Verification Program; no public benchmarks in the main model notes (the coding notes cite a SWE-bench Verified score).
Levelmodel
ClassLLM
Parametersnot in the notes
Contextnot in the notes
Releasednot in the notes
Opennessproprietary
Runs onnot in the notes
Statusactive
Benchmark Results
vendor-reported
SWE-bench Verifiedcoding
max effortvendor-reported
95.5
050100
Score in %. Higher is better.
Where this comes from
Every score names who ran it: vendor-reported, maintainer-run or independent. A rank is shown with the population it was ranked in (gap rule 3).
Lineage
successorproduct of
Claude Fable 5 is a child (product of)low confidencepress claimClaude Mythos 5.1 is a child (successor)low confidencenotesWhere this comes from
Parent and child relations from model cards, Hugging Face base_model fields and the genealogy tables of the research notes. The tree shows two generations each way, 4 models. Confidence and evidence are the notes' own.
R&D Topics
Identity
Where this comes from
Developer and dates from the research notes. Release date is the vendor's public announcement; weights date is when open weights were published.
Architecture and Size
- Architecture
- not in the notes
- Total parameters
- – sources
- Active parameters
- –
- Checkpoint parameters
- –
- Context length
- not in the notes
- Input
- text
- Output
- text
Where this comes from
Parameter counts as the developer states them. Where the checkpoint holds a different total, both are shown (register A16).
Openness and Access
- Openness
- proprietary
- Licence
- Proprietary sources
- Access routes
- gated preview
Where this comes from
The licence file governs over registry tags and aggregator labels.
Deployment
- Runs on
- not in the notes
- Footprint
- not in the notes
- Runtimes
- not in the notes
Where this comes from
Deployment tiers and runtimes as named in the notes. Footprint is the notes' figure, not a measurement by AURION.
Indonesia
- Indonesian support
- not stated
- Regional languages
- not in the notes
- Jakarta hosting
- unknown
- Languages
- not in the notes
Where this comes from
Indonesia fields are carried on every model; unknown is an allowed value.
Industry Use Cases
No industry use case links this model.
Links
DeveloperAnthropicfrontier lab, USA
Anthropicfrontier lab, USAModelClaude Mythos 5Anthropic, LLM
Claude Mythos 5Anthropic, LLMR&D TopicsAgentic Software EngineeringDomain Adaptation (Vertical Models)Frontier Pretraining Scaling
Use CasesIndustrial Copilots and Maintenance AssistantsIndustrialClinical LLM (Frontier Proprietary)HealthcareClinical LLM (Open Weights)HealthcarePharma Documents, Regulatory and Life-Science R&DHealthcare+12 moreUse cases of models in the same R&D topic; none is recorded for this model itself.
Who Runs It
Kementerian Kesehatan (Kemenkes), PusdatinPlanned, 19 Aug 2026
PT Pertamina Geothermal EnergyIn production, 14 Jul 2026
Banner HealthIn production, 11 Jan 2026CommureIn production, 11 Jan 2026+49 moreDeployments of these use cases; none names this model.
Kementerian Kesehatan (Kemenkes), PusdatinPlanned, 19 Aug 2026PT Pertamina Geothermal EnergyIn production, 14 Jul 2026Banner HealthIn production, 11 Jan 2026CommureIn production, 11 Jan 2026+49 moreDeployments of these use cases; none names this model.Models 3
Organisations 1
R&D topics 3
Frontier Pretraining ScalingTraining a new base model at or near the top-5 compute of its release date (Epoch's front…produced byDomain Adaptation (Vertical Models)Training or tuning models for a sector.used byAgentic Software EngineeringTraining and evaluating models that act as agents in real repositories, reading code, run…produced by
Sources
- Newsroom anthropic.com https://www.anthropic.com/news
- Best AI models, October 2026: Opus 5.5, GPT-6, Gemini slash-digital.io https://slash-digital.io/en/insights/ai-models-2026/
- Anthropic releases Claude Opus 5.5 with Fable 5.1-level performance at lower cost - AI News vpsranking.com https://vpsranking.com/news/ai/ai-2026-09-22-anthropic-claude-opus-5-5/
- Text Arena: LLM Rankings & AI Model Benchmarks arena.ai https://arena.ai/leaderboard/chat/text
- leaderboard.steel.dev/leaderboards/swe-bench-verified.md https://leaderboard.steel.dev/leaderboards/swe-bench-verified.md
- Claude Fable 5: 93.9% en SWE-bench y lo que significa para founders – El Ecosistema Startup ecosistemastartup.com https://ecosistemastartup.com/claude-fable-5-93-9-en-swe-bench-y-lo-que-significa-para-founders/
- Claude Opus 5.5: Fable-Class Work, Cheaper to Run llm-stats.com https://llm-stats.com/blog/research/claude-opus-5-5-launch
To cite this page: Project AURION, AI Use-Cases Research & Innovation, "Claude Mythos 5", https://aurion.semai.id/models/anthropic-claude-mythos-5/, records of October 2026.