Building an AI Mediator: Multi-LLM Architecture for Legal Dispute Resolution

At Acuerdio (https://acuerdio.com), we built Spain's first AI-powered online mediation platform. Here's how we designed a multi-LLM architecture that understands legal conflicts and proposes fair solutions.

The Problem

Spain's new law (LO 1/2025) requires parties to attempt alternative dispute resolution before going to court. That's millions of potential cases — from neighbor disputes to family conflicts — that need a scalable, AI-assisted mediation process.

We needed an AI system that could:

• Understand legal context in Spanish
• Propose balanced solutions to both parties
• Generate legally valid documents
• Handle sensitive emotional situations with empathy

Architecture: Multi-Provider LLM Strategy

We don't rely on a single LLM. Our architecture uses multiple providers with intelligent routing.

Why Multi-LLM?

1. Resilience — If one provider goes down, we failover automatically
2. Cost optimization — Use cheaper models for simple tasks
3. Best-of-breed — Each model excels at different aspects of mediation
4. Compliance — We can route sensitive data to EU-hosted models

The Mediation Pipeline

1. Case Analysis → Understand the conflict type and legal framework
2. Party Profiling → Assess each party's position and interests
3. Proposal Generation → Create balanced resolution proposals
4. Agreement Drafting → Generate legally binding documents

Legal Context Understanding

Spanish legal mediation has specific requirements. We built a RAG system with:

• Spanish Civil Code
• LO 1/2025 (mandatory ADR law)
• Regional mediation regulations
• CGPJ case law database

AI-Assisted Proposals

The AI generates resolution proposals that consider:

• Legal precedent for similar cases
• Both parties' stated interests
• Fair distribution principles
• Enforceability of the agreement

Tech Stack

• Backend: Django 5 + DRF + Channels (WebSocket for real-time mediation)
• Database: PostgreSQL 16 with pgvector for embeddings
• Task Queue: Celery + Redis for async LLM calls
• Frontend: Remix 2 + React 18
• Video: Daily.co for live mediation sessions
• Signatures: eIDAS-compliant electronic signatures

Results

• AI resolves ~70% of simple disputes without human mediator involvement
• Average case resolution: under 72 hours (vs 14.3 months for courts)
• Cost: from 9 EUR (vs 3,000-10,000 EUR for litigation)

What's Next

• Voice-based mediation using real-time speech-to-text
• Predictive analytics for case outcomes
• Multi-language support (Catalan, Basque, Galician)

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Acuerdio is Spain's first AI-powered mediation platform. Try it at acuerdio.com