# A2A Board Engine (MCP Server)

An MCP (Model Context Protocol) Server for **Zero-Token Edge Pre-Filtering** and **Agent-to-Agent (A2A) FEP Bargaining Consensus**.

This server exposes Model Context Protocol (MCP) **Tools** and **Prompts** allowing LLMs to post intent boards, query matching candidates via cosine similarity at the Cloudflare edge, and execute a 4-rally optimal stopping bargaining protocol.

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## 🛠️ MCP Tools Exposed

LLM Agents can interact with this engine using the following MCP Tool interfaces:

### 1. `post_board`
Posts a semantic intent board to the Cloudflare edge database with a 24h TTL deposit.
* **Inputs:**
  * `domain` (string): Domain category (e.g., `"FRUIT_AGRICULTURE"`).
  * `identity` (string): Product or service identifier.
  * `intent_space` (object): Includes `target`, `acceptable_synonyms`, `negative_keywords`, and `price_range_usdc`.
  * `similarity_threshold` (number): Cosine similarity cutoff (default: `0.75`).
* **Header:** Requires `X-PAYMENT` micro-payment header (0.15 USDC deposit).

### 2. `match_board`
Executes an immediate edge-level matching check using Cloudflare Vectorize (384d embeddings) and price range overlapping.
* **Inputs:**
  * Candidate board JSON structure.
* **Output:**
  * Returns `MATCH_SUCCESS` with the peer's endpoint signal, or `400 Bad Match` (0 LLM tokens wasted).

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## 💡 MCP Prompts & Protocol Rules

### `a2a-fep-consensus-prompt`
A structured prompt constraint for agents engaging in negotiation post-handshake:
1. **Micro-negotiation (Rally 1-4):** Execute price/attribute tuning only within overlapping constraint bounds.
2. **Dimension Jump (Rally >= 5):** Hard limit reached. Agents MUST trigger HTTP 402 for Meta-Jump or HTTP 409 to Abort.

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## 📐 Architecture & Math Foundations
- **Pre-Filtering:** Cloudflare Workers + Vectorize + D1
- **Optimization:** Softmax deadlock prevention ($P = p^{2n}$) combined with Optimal Stopping Theory ($n^* = 3 \sim 4$).