snhp

# SNHP

[![smithery badge](https://smithery.ai/badge/ryuxik/snhp)](https://smithery.ai/servers/ryuxik/snhp)

**Free negotiation math for AI agents. One call, no account.** Your agent brings
the LLM; SNHP brings the game theory — your math-optimal next move in any
negotiation, single-price *and* multi-issue, LLM-free, runs locally. When you
need it **on the record**: $2 receipted sessions. When you need it to
**remember**: agent memory (blind custody — you encrypt before saving; we store
only ciphertext and cannot read it).

[![PyPI](https://img.shields.io/pypi/v/snhp.svg)](https://pypi.org/project/snhp/)
[![License: Apache 2.0](https://img.shields.io/badge/License-Apache_2.0-blue.svg)](LICENSE)
 ·  [snhp.dev](https://snhp.dev)  ·  [Manifesto](MANIFESTO.md)

## 🏆 The Negotiation Leaderboard

**[arena.snhp.dev/leaderboard.html](https://arena.snhp.dev/leaderboard.html)** —
which AI walks away with the most money? Claude models, a naive
splitter, a genome evolved in a live sim, and community bots all negotiate the
same held-out multi-issue deals against the SNHP engine, scored against the
exact Pareto frontier. Every match is a real recorded negotiation, replayable
in the browser. Headline result: **frontier models, solo, lose to the naive
split-the-difference bot** — wired to the engine mid-deal, they're near-optimal.

**Put your bot on the board:** expose one HTTP endpoint speaking
[`snhp-gauntlet/1`](https://arena.snhp.dev/submit.html) and DM
[@ryuxik](https://x.com/ryuxik) the URL. The runner lives in
[`arena/gauntlet/`](arena/gauntlet/) — protocol, seats, scoring, and the
[25-line starter bot](arena/gauntlet/examples/demo_bot.py). Machine-readable
spec: [arena.snhp.dev/llms.txt](https://arena.snhp.dev/llms.txt).

## Install

```bash
uvx snhp            # zero-install: runs the stdio MCP server on demand
# or
pip install snhp
```

Wire it into any MCP client (Claude Desktop, Cursor, Cline, …):

```json
{ "mcpServers": { "snhp": { "command": "uvx", "args": ["snhp"] } } }
```

Or call the math directly — plain dollars in, the move out (the `negotiate` tool):

```python
from gametheory.negotiation.plain_terms import negotiate_turn

negotiate_turn(
    side="sell", walk_away=4000, target=6000,
    counterparty_offers=[4200, 4500], rounds_left=6,
)
# -> {'action': 'counter', 'recommended_price': 5752.2,
#     'message': 'Thanks for the offer. The best I can do on this is $5,752.20.', ...}
```

Multi-issue deals logroll automatically — SNHP infers the other side's priorities
and proposes the package that maximises joint surplus (concede what you value
least to hold what you value most):

```python
from gametheory.negotiation.bundle import negotiate_bundle

negotiate_bundle(
    issues=[
        {"name": "price",   "options": [100, 120, 140], "my_utility": [1.0, 0.5, 0.0], "their_utility": [0.0, 0.5, 1.0]},
        {"name": "support", "options": ["basic", "priority"], "my_utility": [1.0, 0.0], "their_utility": [0.0, 1.0]},
    ],
    my_priorities={"price": 0.8, "support": 0.2},
)
# -> recommended_offer {'price': 100, 'support': 'priority'} + the trade logic behind it
```

Hosted agent card, streamable MCP, and a live demo: **[snhp.dev](https://snhp.dev)**.

## What's here

```
snhp/                   Core algorithm + NegMAS agent + B2B tournament harness
gametheory/             Productization layer (FastAPI, MCP, Tier 1/2/3 endpoints)
gametheory/negotiation/ Plain-terms single- + multi-issue (logrolling) engines
gametheory/server/      HTTP + MCP entry points
gametheory/tests/       pytest suite
SNHP_Whitepaper/        Protocol description + 3 component PRDs
```

## Develop from source

```bash
git clone https://github.com/ryuxik/snhp && cd snhp
python -m venv venv && source venv/bin/activate
pip install -e ".[test]"

python -m pytest gametheory/tests/                  # test suite
uvicorn gametheory.server.http:app --reload         # local API (catalog at /v1/catalog)
snhp                                                # stdio MCP server
```

## Empirical anchor

### Two different numbers — keep them straight

There are two distinct measurements; conflating them is the easy mistake.

**1. Head-to-head competitive margin (the product-relevant number).** In a
SNHP-scaffolded LLM vs a non-SNHP LLM, how much more of the surplus does the SNHP
side capture? On the committed cross-vendor run (`gametheory/server/static/e6_cross_vendor.json`,
Sonnet+SNHP vs Haiku, n=20 paired seeds) the pooled margin is **~+12.5%**
(`mean h3_margin ≈ 0.125`, 29/40 positive signs). This is the number the shipped
tools cite as "~12% better head-to-head." Caveats: n=20, LLM-vs-LLM, single-issue
price, and the opponent is a *general* vanilla prompt — see the strong-baseline
note below.

**2. Joint-welfare lift in self-play (a cooperation metric, NOT the same thing).**
Two-Sonnet B2B contract negotiation, n=20 paired seeds:

| Condition | Joint welfare (frontier ≈ 1.57, estimated) |
|---|---:|
| Vanilla Sonnet (general prompt, no SNHP) | 1.40 |
| Pure SNHP-vs-SNHP (math only) | 1.45 |
| **Sonnet + SNHP MCP tool (both sides)** | **1.59** |
| Haiku + SNHP MCP tool (cross-model) | 1.61 |

Lift from both sides adopting the SNHP tool: **+0.186 joint welfare**, sign test
18/20, **p=0.0004**. (The 1.59/1.61 slightly exceed the 1.57 frontier *estimate* —
the frontier was estimated on a coarse grid, so treat these as "at the frontier,"
not "beyond it.") Cost: $0.025 per matchup at 2026-04 pricing.

### 3. The build-vs-buy test: SNHP vs a STRONG production prompt

Both numbers above are vs a *general* vanilla prompt. The sharper question — "why not
just prompt the LLM well?" — is answered by running SNHP against a strong production
prompt (`snhp/llm_strong_baseline.py`, whose system prompt even includes logrolling
advice). On the 4-issue contract, Haiku+SNHP-tool vs Haiku+strong-prompt, n=12 paired
seeds (`python -m snhp.strong_baseline_headtohead`, result committed at
`gametheory/server/static/strong_baseline_headtohead.json`):

| Metric | Value |
|---|---|
| Utility margin (SNHP − strong baseline) | **+0.077**, 95% CI **[+0.039, +0.115]** (excludes 0) |
| SNHP share of joint surplus | **54%** (CI [52%, 56%]) |
| Sign test | **8/12 positive, 0 negative** |

SNHP beats even a strong production prompt — but by roughly **half** the edge it shows
against a weak one. Caveats: n=12, Haiku (not Sonnet), one contract domain; re-run at
larger n / a stronger model to tighten the CI.

**Network effect**: the cooperation premium requires both sides to be
SNHP-staked. Asymmetric matchups (Sonnet+SNHP vs vanilla Sonnet) lose 0.11
utility vs symmetric scaffolded play. Peer-mode advisor only fires when
counterparty has posted a verifiable SNHP attestation.

Live demo (replay of the actual API trace at seed=42): https://snhp.dev/demo.html

### Tournament rank (honest, per-market)

In the committed round-robin (`leaderboard/results/leaderboard.json`, `n_rounds=20`),
SNHP's rank by average utility depends on the market:

| Market (BATNA) | SNHP rank | Top of field |
|---|---|---|
| Buyer's market (asymmetric) | **#1 of 21** | SNHP 0.508 |
| Seller's market (asymmetric) | **#1 of 21** | SNHP 0.520 |
| Symmetric (neutral) | **5th of 21** | Logroller 0.525, The Closer, Cialdini, Principled, then SNHP 0.512 |

So SNHP is #1 **in the asymmetric markets** and **mid-pack in the symmetric one** —
do not read this as "#1 overall." Its variance is the smallest in the field. At
`n_rounds=100` the symmetric field restabilizes further and Aspiration leads.

This NegMAS agent (`snhp/negmas_agent.py`) is a **research artifact and is NOT the
shipped product recommender** — the product claims below are measured on the
shipped code, not on this tournament.

See `gametheory/evals/README.md` for the eval/tuning runbook.

## Tiers

- **Tier 1 — Negotiation**: sell-side + buy-side recommenders, anchor-attack
  detection, cryptographic first-strike commit-reveal, LLM-drafted reply
  emails (paid).
- **Tier 2 — Auctions**: Vickrey / first-price BNE / English ascending,
  Myerson optimal reserve, format recommendation, MC simulation.
- **Tier 3 — Mechanism design**: Gale-Shapley, asymmetric Myerson optimal
  auction, Gallego-van Ryzin posted-price.

Tier 4 (coalition games) deferred until a paying buyer asks for it.

---

mcp-name: io.github.ryuxik/snhp-negotiation