Phase 16: Multi-Agent & Swarms

Negotiation and Bargaining

Agents negotiate resources, prices, task allocations, and terms. The 2026 benchmark set is clear: NegotiationArena (arXiv:2402.05863) shows LLMs can improve payoffs 20% via persona manipulation ("desperation"); "Measuring Bargaining Abilities" (arXiv:2402.15813) shows buyer is harder than seller and scale does not help — their OG-Narrator (deterministic offer generator + LLM narrator) pushed deal rate from 26.67% to 88.88%; the Large-Scale Autonomous Negotiation Competition (arXiv:2503.06416) ran 180k negotiations and found that chain-of-thought-concealing agents win by hiding reasoning from counterparts; Bhattacharya et al. 2025 on Harvard Negotiation Project metrics ranked Llama-3 most-effective, Claude-3 aggressive, GPT-4 fairest. This lesson implements Contract Net Protocol (the FIPA ancestor, Lesson 02), wires an LLM-style buyer/seller, runs an OG-Narrator-style decomposition, and measures how deal rate changes with each structural choice. Two agents need to agree on a price. Left to themselves with pure language prompts, 2024-2026 LLMs close deals at surprisingly low rates (27% on tightly-parameterized bargains in arXiv:2402.15813). Scale does not fix it: GPT-4 is not structurally better at bargaining than GPT-3.5; it is better at the language of bargaining. The root issue is that LLMs conflate two jobs — deciding the offer and narrating the offer. OG-Narrator separated these: a deterministic offer generator computes numeric moves; the LLM only narrates. Deal rate jumps to 89%. This mirrors a classical multi-agent finding: decoupling the mechanism from the…

Negotiation and Bargaining: Agents negotiate resources, prices, task allocations, and terms. The 2026 benchmark set is clear: NegotiationArena…

This free lesson is part of the AI Engineering from Scratch curriculum. Read the full explanation, run the lesson code, and verify the result in the interactive reader or from the repository source.

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