feat: MCP server + Paytaca AI integration (ai configure, provider, API keys)

README.md

@@ -146,34 +146,34 @@ paytaca pay https://api.example.com/v1/complete --method POST --body '{"prompt":
 # → Handles 402 → pays → returns response
 ```
 
-### AI Agent Integration
+### AI Agent Integration (MCP + Paytaca AI)
 
-Paytaca CLI provides AI agent skills for wallet operations. Install from GitHub (supports 45+ AI frameworks):
+Configure an AI harness in one step. This installs the Paytaca MCP server and, for opencode, also the Paytaca AI provider (model catalogue + API key) so the Paytaca AI models are usable immediately:
 
 ```bash
-# Install specific skill
-npx skills add paytaca/paytaca-cli --skill <skill-name> -a <agent> -g
+paytaca ai configure opencode   # claude | opencode | cursor | codex | pi | generic
+```
+
+The command creates a wallet-bound API key against the Paytaca AI backend, writes the provider (base URL, models, key) and MCP server into the harness config, then checks your AI credits and offers to buy a plan when none are active.
 
-# Install all skills
-npx skills add paytaca/paytaca-cli --all
+Re-running is idempotent: an existing provider API key is reused. Then run the server over stdio:
 
-# Examples
-npx skills add paytaca/paytaca-cli --skill paytaca-x402 -a opencode -g
-npx skills add paytaca/paytaca-cli --skill paytaca-wallet -a claude-code -g
-npx skills add paytaca/paytaca-cli --skill paytaca-send -a openclaw -g
+```bash
+paytaca mcp
 ```
 
-**Available Skills:**
+**Read-only wallets:** if the active wallet cannot sign (no seed phrase in the keychain), `ai configure` asks for an API key instead of creating one. Generate it from your full wallet and hand it over:
+
+```bash
+paytaca ai api-key create                          # full wallet: prints sk-pytc-… once
+paytaca ai configure opencode --api-key sk-pytc-…  # read-only wallet
+```
 
-| Skill | Purpose | Approval Needed |
-|-------|---------|------------------|
-| `paytaca-x402` | HTTP 402 payment handling | Yes (before payment) |
-| `paytaca-wallet` | Balance, addresses, history, token info | No (read-only) |
-| `paytaca-send` | Send BCH and CashTokens | Yes (before sending) |
+Read-only wallets report credits from the shared wallet hash but can't buy plans — fund credits from the full wallet.
 
-**Supported frameworks:** OpenCode, Claude Code, OpenClaw, Cursor, Cline, Windsurf, Roo, Gemini CLI, Codex, GitHub Copilot, Goose, Trae, Kiro CLI, and 30+ more.
+**MCP tools:** wallet reads (`get_balance`, `get_transactions`, `get_receiving_address`, `get_tokens`, `send`) plus Paytaca AI (`get_models`, `get_plans`, `get_credits`, `buy_plan`, `auto_refill`, `get_help`).
 
-See [skills/README.md](skills/README.md) for detailed skill documentation.
+Spending tools (`send`, `buy_plan`, `auto_refill`) require host-level approval. By default MCP operates on your **main wallet** and can spend real funds.
 
 ## Network
 
@@ -224,6 +224,10 @@ src/
     x402.ts          x402 header parsing, payment requirement selection
   types/
     x402.ts          x402 payment types (PaymentRequired, PaymentPayload, etc.)
+  ai/
+    client.ts        Paytaca AI backend client (config, wallet status, chat)
+    oauth.ts         BCH OAuth challenge -> access token -> API key
+    configure.ts     Harness setup (MCP + Paytaca AI provider + credits offer)
 ```
 
 ## Key Dependencies