# Xynthera AI — Remote prepaid MCP

Endpoint: https://pfxxzsnboehxsefyajml.supabase.co/functions/v1/xynthera-ai-payg-mcp/mcp

The remote bridge consumes already-paid credit from the three prepaid APIs. No OAuth, purchase tool, automatic recharge, supplier payment or assurance-family entitlement. Your private `payg.…` budget code is an HTTP Bearer credential, never a model prompt or tool argument. A client must support protected custom HTTP headers; compatibility with OAuth-only/native ChatGPT connections is not claimed.

## Connect

1. Choose a manually confirmed €10–€10,000 budget and save its private code.
2. Configure the endpoint and protected headers in your compatible client: `Authorization: Bearer YOUR_PRIVATE_BUDGET_CODE`, `Content-Type: application/json`, `Accept: application/json, text/event-stream`.
3. Initialize using `2025-11-25`, `2025-06-18` or `2025-03-26`, send `notifications/initialized`, then include the negotiated `MCP-Protocol-Version` header. First call the free `get_budget_status` tool before explicitly authorising paid checks.

Free status JSON-RPC body (the Bearer credential belongs in a separate protected HTTP header):

```json
{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"get_budget_status","arguments":{}}}
```

Tools: `reconcile_invoice` (€0.005 HT), `check_contract` (€0.010 HT), `check_events` (€0.002 HT per batch of 1–200). Their `arguments` are the complete prepaid API input object directly, including `request_id`; do not wrap in `{input: ...}`. Read the prepaid OpenAPI and guide for complete examples and input limits.

The remote bridge has no local per-session ceiling. The purchased net server balance caps total spending; explicitly authorise use in your client. A discrepancy is a completed, chargeable analysis. Invalid input consumes no credit. Preserve the exact input and request_id for a deliberate retry; never automatically retry or generate a new ID after an uncertain outcome. Replay reconstruction is limited to 30 days of metadata. Save the returned report and signature yourself; they are not archived by this prepaid service.

## Local bridge

The separate Node.js 20+ stdio bridge in the integration ZIP accepts `{input: ...}` for paid tools and starts with a zero default session ceiling in the example configuration. Its ceiling covers one process, not a persistent account limit. Restart resets its local counter. See `mcp-onboarding.md`. Neither bridge can buy or automatically reload credit.

## Existing subscriptions

The legacy x-api-key MCP endpoint and guide are for previously accepted subscriptions only. They do not authenticate a prepaid budget code.