Claude Mythos 5.1

proprietary
Input price
$10/1M tokens
Output price
$50/1M tokens

Capabilities

Reasoning & Interaction
Tool Calling
Infrastructure
Streaming
Batch Processing

Details

Model IDclaude-mythos-5-1
Provider Anthropic
Creator anthropic
Familyclaude-mythos
Licenseproprietary
Status—
Typechat
Input modalitiestext, image
Output modalitiestext
Open weightNo
Parameters—
Architecture—
Context window—
Max input—
Max output—
Reasoning tokens—
Knowledge cutoff—
Release date—
Retirement date
Sourceofficial

Tools

Function Callingfunction_calling
Call external functions and APIs

Endpoints

MessagesPOST
Create messages with multi-turn conversationshttps://api.anthropic.com/v1/messages

Pricing

Input
$10
Output
$50
Cache write (5m)
$12.5
Cache write (1h)
$20
Cache read
$0.25
Batch in
$5
Batch out
$25

Family Comparison: claude-mythos

ModelContextMax outPricing
Claude Mythos 5.1——$10$50
Claude Mythos 51M128K$10$50

API

GET/v1/models/anthropic/claude-mythos-5-1

Claude Mythos 5.1

claude-mythos-5-1
Changes · 3 entries
claude-mythos-5-1createca7a400Nov 2, 2026, 03:02 AM
claude-mythos-5-1update3170597Sep 19, 2026, 06:34 AM
retirement_date2027-09-01
claude-mythos-5-1create77b8547Sep 2, 2026, 06:42 AM