How to Configure Quota Management with MCP Server Tools in OmniRoute

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, 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, 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 service retrieves raw quota data from /api/usage/quota, while quotaMonitor.ts maintains a normalized view using normalizeQuotaResponse from 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.

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.

# 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.

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

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

Example Response:

{
  "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.

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.

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 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 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 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 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, 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.
• 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.
• 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. 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 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 via the normalizeQuotaResponse helper. This ensures that responses from different provider APIs conform to a consistent structure containing quotaUsed, quotaTotal, percentRemaining, and resetAt fields.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}