# How to Configure Quota Management with MCP Server Tools in OmniRoute

> Configure quota management with OmniRoute MCP server tools. Learn to inspect usage across providers using the omniroute_check_quota tool and API endpoint.

- Repository: [Diego Rodrigues de Sa e Souza/OmniRoute](https://github.com/diegosouzapw/OmniRoute)
- Tags: how-to-guide
- Published: 2026-08-01

---

**Use the `omniroute_check_quota` tool exposed by the OmniRoute MCP server to inspect quota usage across providers by calling the internal `/api/usage/quota` endpoint with `read:quota` scope validation.**

The OmniRoute repository provides a Model Context Protocol (MCP) server that exposes built-in tools for managing API quotas across multiple LLM providers. Configuring quota management with MCP server tools allows operators to monitor consumption, enforce budget limits, and prevent service interruptions through standardized JSON-RPC interfaces.

## Understanding the Quota Management Architecture

The quota management system consists of four primary components working together to provide real-time usage data:

- **MCP Server Runtime** – Registers tools and routes calls to handlers. Located in [`open-sse/mcp-server/server.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/server.ts), this component validates scopes and dispatches requests to the appropriate tool implementation.

- **Tool Schema Definition** – Defines input validation and metadata. In [`open-sse/mcp-server/schemas/tools.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/schemas/tools.ts), the Zod schema for `omniroute_check_quota` specifies the optional `provider` parameter and enforces the `read:quota` scope requirement.

- **Quota Services** – Fetch and normalize data. The [`quotaPreflight.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/quotaPreflight.ts) service retrieves raw quota data from `/api/usage/quota`, while [`quotaMonitor.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/quotaMonitor.ts) maintains a normalized view using `normalizeQuotaResponse` from [`src/shared/contracts/quota.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/src/shared/contracts/quota.ts).

- **Transport Layers** – Accept connections via stdio, HTTP, or Server-Sent Events (SSE). All transports expose the same JSON-RPC interface defined in [`open-sse/mcp-server/server.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/server.ts).

## Prerequisites and Scope Configuration

Before invoking quota tools, ensure your API key includes the **`read:quota`** scope. The MCP server enforces this requirement through `withScopeEnforcement("omniroute_check_quota", ...)` in the server registration code. Without this scope, the tool returns a 403 authorization error.

The tool optionally accepts a `provider` parameter to filter results to a specific service (e.g., `"anthropic"` or `"google"`). Omitting this parameter returns quota data for all connected providers.

## Using the omniroute_check_quota Tool

The MCP server exposes quota data through four primary invocation methods.

### Method 1: MCP CLI

The OmniRoute CLI wraps JSON-RPC calls to the stdio transport for local execution.

```bash

# Check quota for all providers

omniroute --mcp --tool omniroute_check_quota

# Check quota for a specific provider

omniroute --mcp --tool omniroute_check_quota --args '{"provider":"anthropic"}'

```

### Method 2: HTTP JSON-RPC

Send POST requests to the HTTP transport endpoint at `/api/mcp`.

```http
POST /api/mcp HTTP/1.1
Content-Type: application/json

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "omniroute_check_quota",
  "params": { "provider": "google" }
}

```

**Example Response:**

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "providers": [
      {
        "provider": "google",
        "quotaUsed": 20,
        "quotaTotal": 200,
        "percentRemaining": 90,
        "resetAt": "2026-08-15T00:00:00Z"
      }
    ]
  }
}

```

### Method 3: Server-Sent Events (SSE)

Use the SSE transport for streaming connections, ideal for real-time monitoring dashboards.

```bash
curl -N http://localhost:3000/api/mcp/sse \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"omniroute_check_quota","params":{}}'

```

The stream emits a JSON-RPC result object once the query completes.

### Method 4: Programmatic Node.js Client

Import the MCP client library to integrate quota checks into applications.

```javascript
import { createMcpClient } from '@omniroute/open-sse/mcp-client';

const client = createMcpClient({ url: 'http://localhost:3000/api/mcp' });

async function showQuota() {
  const result = await client.call('omniroute_check_quota', {});
  console.table(result.providers, ['provider', 'quotaUsed', 'quotaTotal', 'percentRemaining']);
}

showQuota();

```

## Understanding the Tool Implementation

The `omniroute_check_quota` tool implementation resides in [`open-sse/mcp-server/server.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/server.ts) within the `withScopeEnforcement` wrapper. When invoked, the execution flow follows these steps:

1. **Request Validation** – The Zod schema in [`open-sse/mcp-server/schemas/tools.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/schemas/tools.ts) validates that the optional `provider` parameter is a string.

2. **Scope Enforcement** – The server checks for the `read:quota` scope using the enforcement wrapper before executing the handler.

3. **Data Retrieval** – The handler calls [`quotaPreflight.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/quotaPreflight.ts) to fetch data from the core `/api/usage/quota` endpoint, optionally filtering by provider.

4. **Normalization** – Raw responses pass through `normalizeQuotaResponse` from [`src/shared/contracts/quota.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/src/shared/contracts/quota.ts) to ensure consistent `quotaUsed`, `quotaTotal`, and `resetAt` fields.

5. **Audit Logging** – Every invocation is recorded via `logToolCall` for compliance tracking.

For composite operations that combine quota data with other metrics, reference [`open-sse/mcp-server/tools/advancedTools.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/tools/advancedTools.ts), which demonstrates how to chain quota checks with additional preflight services.

## Summary

- **Primary Tool**: Use `omniroute_check_quota` to inspect quota usage across all providers or filter by a specific provider.
- **Required Scope**: Ensure API keys include `read:quota` scope as enforced in [`open-sse/mcp-server/server.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/server.ts).
- **Transport Options**: Access via CLI (stdio), HTTP POST, SSE streams, or the Node.js MCP client.
- **Data Source**: Quota information originates from `/api/usage/quota` and is normalized through [`src/shared/contracts/quota.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/src/shared/contracts/quota.ts).
- **Audit Trail**: All tool calls are logged automatically via `logToolCall` for security monitoring.

## Frequently Asked Questions

### What scope is required to check quotas via MCP tools?

The **`read:quota`** scope is mandatory. The MCP server validates this scope using `withScopeEnforcement("omniroute_check_quota", ...)` in [`open-sse/mcp-server/server.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/server.ts). API keys without this scope receive an authorization error when attempting to invoke the tool.

### How does the MCP server validate quota requests?

Validation occurs in two stages. First, the Zod schema in [`open-sse/mcp-server/schemas/tools.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/mcp-server/schemas/tools.ts) validates the input shape. Second, the scope enforcement wrapper verifies the API key permissions. Only then does the handler execute the quota fetch logic.

### Can I check quota for a specific provider only?

Yes. Pass the optional `provider` parameter (string) in the tool arguments to filter results to a single provider. Omitting this parameter returns quota information for all connected providers in the `providers` array.

### Where is the quota data normalized before returning to the client?

Normalization occurs in [`src/shared/contracts/quota.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/src/shared/contracts/quota.ts) via the `normalizeQuotaResponse` helper. This ensures that responses from different provider APIs conform to a consistent structure containing `quotaUsed`, `quotaTotal`, `percentRemaining`, and `resetAt` fields.