โšก Open Source ยท MIT ยท By eulogik

Fugu Sashi.
Served Free.

The open-source model router that learns from every request, runs on your infrastructure, and puts every AI model at your fingertips โ€” better than Sakana Fugu, zero vendor lock-in, zero monthly fees.

โญ Star on GitHub Get Started โ†’ ๐Ÿ“ฆ PyPI

Features

Everything Fugu does, plus what it can't.

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Intelligent Routing

Three strategies โ€” similarity, cost, and fallback โ€” pick the best model for every prompt in under 20ms.

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Feedback Loop

Learns from every request. Auto-retrains after every 10 requests. Gets smarter over time.

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Fully Transparent

Every routing decision is visible. No black box. See which model was picked and why.

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Self-Hosting

Run entirely on-premise with local models via Ollama. Air-gapped capable. No cloud dependency.

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Live Dashboard

Real-time web dashboard showing routing decisions, model usage, costs, and latency.

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OpenAI-Compatible

Drop-in replacement for OpenAI API. Works with any OpenAI SDK. 100+ providers via LiteLLM.

Fugusashi vs Sakana AI Fugu

See why developers are switching to open source.

Fugusashi vs Sakana AI Fugu Comparison
FeatureSakana FuguFugusashi
Model Routingโœ“ Proprietaryโœ“ Open & transparent
Multi-Agent Orchestrationโœ“ Fugu Ultraโœ“ Phase 2
Self-HostingโŒ Cloud-onlyโœ“ Local-first
Cost$5-30/M tokensโœ“ Free
TransparencyโŒ Black boxโœ“ Every decision visible
Feedback LoopโŒ Staticโœ“ Learns from every request
Model PoolโŒ Fixed by Sakanaโœ“ You control
Training DataโŒ Proprietaryโœ“ Community + your traffic
LicenseProprietaryโœ“ MIT

Quickstart

Up and running in 5 minutes.

# Install from PyPI
pip install fugusashi

# Or run with Docker
docker run -p 6060:6060 ghcr.io/eulogik/fugusashi:latest

# Or from source
git clone https://github.com/eulogik/fugusashi.git
cd fugusashi && pip install -e .

# Run
fugusashi serve --config config.yaml

# Use
curl http://localhost:6060/v1/chat/completions -H "Content-Type: application/json" -d '{"model":"auto","messages":[{"role":"user","content":"Say hello"}]}'

# Open dashboard
open http://localhost:6060/dashboard

Architecture

Two tiers. One fast router. One deep orchestrator.

Fugusashi Architecture Diagram

CMA-ES Coordinator

The learning brain. Evolves to pick the best model for every prompt.

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Prompt
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Embed
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โšก
Route
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๐Ÿ“Š
Evaluate
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Evolve
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Inspired by Sakana AI's TRINITY paper. Uses CMA-ES (Covariance Matrix Adaptation Evolution Strategy) to evolve routing weights. Runs locally in under 1ms per decision. Gets smarter from every request.

Feedback Loop

Learns from every request. Gets smarter over time.

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Route
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โšก
Execute
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๐Ÿ“Š
Evaluate
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๐Ÿ“š
Learn
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Outcomes are recorded automatically. After every 10 requests, the similarity router retrains. Over time it learns which prompts work best with which models โ€” without any manual intervention.

Benchmarks

85%
Routing Accuracy
90%
Code Task Accuracy
<20ms
Routing Latency
100+
Supported Providers

Federated Routing

Collaborative routing without data sharing.

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Hospital A
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Startup B
+
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Enterprise C
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Federated Avg
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Global Router

Each organization trains locally on their own data. Only weight updates (with differential privacy noise) are shared. The result is a router smarter than any single deployment.

Human-Interpretable Explanations

Every routing decision comes with a natural language explanation.

POST /v1/explain {"prompt": "Write a Python class for a binary tree"}

Decision: Route to gpt-oss-120b (confidence: 87%)
Why: This prompt involves code generation. gpt-oss-120b is best suited for complex reasoning.

Alternatives considered:
- lfm-2.5-1.2b (12%): better for fast responses
- hermes-3-405b (1%): better for creative writing

Latency: 5.5ms | Strategy: cma-es

Paper

Research contributions: federated routing learning, human-interpretable routing, CMA-ES adaptation.

Read the Paper

Links

๐ŸŒ Website

eulogik.com

๐Ÿค— HuggingFace

Model ยท Dataset ยท Live Demo

๐Ÿ“– This Site

eulogik.github.io/fugusashi