stack-sakana.stack.json json {
"osr": "1",
"kind": "stack",
"name": "Sakana tiers",
"description": "Sakana only: Sakana Namazu for everyday requests, Fugu Ultra for moderate work, Fugu Ultra v2 for hard ones - with complexity rules and a cost-aware objective.",
"targets": [
{
"ocm": "1",
"id": "model-sakana-sakana-namazu",
"kind": "llm",
"name": "Sakana Namazu",
"description": "Sakana Namazu is a Japanese-specialized reasoning model from Sakana AI, based on Kimi K2.6 with additional training for Japanese language and business contexts. It is suited for Japanese instruction following,...",
"publisher": "Sakana",
"version": "1.0.0",
"capabilities": {
"domains": [
"general"
],
"tags": [
"llm",
"sakana",
"openrouter",
"reasoning",
"tool-calling",
"image",
"file",
"models"
],
"languages": [
"en"
],
"modalities": [
"text",
"image",
"file"
],
"supports_tools": true,
"supports_streaming": true,
"context_window": 262144
},
"quality_prior": 0.6,
"examples": [
"Sakana Namazu is a Japanese-specialized reasoning model from Sakana AI, based on Kimi K2.6 with additional training for Japanese language and business contexts. It is suited for Japanese instruction following,..."
],
"primary": false,
"metadata": {
"source": {
"provider": "models",
"ref": "1786410129",
"url": "https://openrouter.ai/sakana/sakana-namazu",
"key": "sakana/sakana-namazu",
"catalogue": "https://openrouter.ai/api/v1"
},
"model": "sakana/sakana-namazu",
"pricing": {
"input_usd_per_1m": 0.95,
"output_usd_per_1m": 4,
"cache_read_usd_per_1m": 0.15
},
"max_output_tokens": 65536,
"output_modalities": [
"text"
],
"reasoning": true,
"created": 1786410129
},
"cost": {
"usd_per_1k_tokens": 0.002475
},
"endpoints": [
{
"protocol": "openai",
"url": "https://openrouter.ai/api/v1"
}
]
},
{
"ocm": "1",
"id": "model-sakana-fugu-ultra",
"kind": "llm",
"name": "Fugu Ultra",
"description": "Fugu Ultra is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to route...",
"publisher": "Sakana",
"version": "1.0.0",
"capabilities": {
"domains": [
"general"
],
"tags": [
"llm",
"sakana",
"openrouter",
"reasoning",
"tool-calling",
"image",
"models"
],
"languages": [
"en"
],
"modalities": [
"text",
"image"
],
"supports_tools": true,
"supports_streaming": true,
"context_window": 1000000
},
"quality_prior": 0.6,
"examples": [
"Fugu Ultra is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to route..."
],
"primary": false,
"metadata": {
"source": {
"provider": "models",
"ref": "1782276303",
"url": "https://openrouter.ai/sakana/fugu-ultra",
"key": "sakana/fugu-ultra",
"catalogue": "https://openrouter.ai/api/v1"
},
"model": "sakana/fugu-ultra",
"pricing": {
"input_usd_per_1m": 5,
"output_usd_per_1m": 30,
"cache_read_usd_per_1m": 0.5
},
"max_output_tokens": 128000,
"output_modalities": [
"text"
],
"reasoning": true,
"created": 1782276303
},
"cost": {
"usd_per_1k_tokens": 0.0175
},
"endpoints": [
{
"protocol": "openai",
"url": "https://openrouter.ai/api/v1"
}
]
},
{
"ocm": "1",
"id": "model-sakana-fugu-ultra-v2",
"kind": "llm",
"name": "Fugu Ultra v2",
"description": "Fugu Ultra v2 is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to...",
"publisher": "Sakana",
"version": "1.0.0",
"capabilities": {
"domains": [
"general"
],
"tags": [
"llm",
"sakana",
"openrouter",
"reasoning",
"tool-calling",
"image",
"file",
"models"
],
"languages": [
"en"
],
"modalities": [
"text",
"image",
"file"
],
"supports_tools": true,
"supports_streaming": true,
"context_window": 1000000
},
"quality_prior": 0.6,
"examples": [
"Fugu Ultra v2 is the higher-performance model in Sakana AI's Fugu family. Rather than a single monolithic model, Fugu is a learned multi-agent orchestration system: a language model trained to..."
],
"primary": false,
"metadata": {
"source": {
"provider": "models",
"ref": "1789105383",
"url": "https://openrouter.ai/sakana/fugu-ultra-v2",
"key": "sakana/fugu-ultra-v2",
"catalogue": "https://openrouter.ai/api/v1"
},
"model": "sakana/fugu-ultra-v2",
"pricing": {
"input_usd_per_1m": 5,
"output_usd_per_1m": 30,
"cache_read_usd_per_1m": 0.5
},
"max_output_tokens": 128000,
"output_modalities": [
"text"
],
"reasoning": true,
"created": 1789105383
},
"cost": {
"usd_per_1k_tokens": 0.0175
},
"endpoints": [
{
"protocol": "openai",
"url": "https://openrouter.ai/api/v1"
}
]
}
],
"rules": [
{
"name": "hard-to-strongest",
"when": {
"min_complexity": 0.7
},
"prefer": [
"model-sakana-fugu-ultra-v2"
]
},
{
"name": "easy-stays-cheap",
"when": {
"max_complexity": 0.3
},
"avoid": [
"model-sakana-fugu-ultra-v2"
]
}
],
"objective": {
"quality": 0.7,
"cost": 0.8,
"latency": 0.2
},
"metadata": {
"source": {
"provider": "catalogue-stacks",
"path": "sakana",
"ref": "2026-09-19",
"url": "https://openrouter.ai/sakana",
"key": "catalogue-stacks/sakana",
"catalogue": "https://openrouter.ai/api/v1",
"generated": true
}
}
}
