/**
* @file Spend Limits Resource Handler
* @description Implements resource handlers for Brex spend limits API endpoints
*/
import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { ReadResourceRequestSchema } from "@modelcontextprotocol/sdk/types.js";
import { logDebug, logError } from '../utils/logger.js';
import { ResourceTemplate } from '../models/resourceTemplate.js';
import { BrexClient } from '../services/brex/client.js';
import { parseQueryParams } from '../models/common.js';
import { isSpendLimit } from '../models/budget.js';
import { estimateTokens } from '../utils/responseLimiter.js';
/**
* Get Brex client
*/
function getBrexClient(): BrexClient {
return new BrexClient();
}
/**
* Resource template for spend limits API
*/
const spendLimitsTemplate = new ResourceTemplate('brex://spend_limits{/id}');
/**
* Register the spend limits resource handler
* @param server - MCP server instance
*/
export const registerSpendLimitsResource = (server: Server): void => {
server.setRequestHandler(ReadResourceRequestSchema, async (request: unknown, _extra: unknown) => {
const req = request as { params: { uri: string } };
const { uri } = req.params;
// Check if we can handle this URI
if (!uri.startsWith('brex://spend_limits')) {
return { handled: false };
}
logDebug(`Handling spend limit request for URI: ${uri}`);
try {
const brexClient = getBrexClient();
// Use parse instead of match to get URI parameters
const params = spendLimitsTemplate.parse(uri);
const id = params.id;
if (id) {
// Get single spend limit
logDebug(`Fetching single spend limit with ID: ${id}`);
const spendLimit = await brexClient.getSpendLimit(id);
if (!spendLimit || !isSpendLimit(spendLimit)) {
throw new Error(`Invalid spend limit data received for ID: ${id}`);
}
const qp = parseQueryParams(uri);
const fields = qp.fields ? qp.fields.split(',').map(s => s.trim()).filter(Boolean) : undefined;
const summaryOnly = qp.summary_only === 'true';
const summarized = summaryOnly || estimateTokens(JSON.stringify(spendLimit)) > 24000;
const out = project(spendLimit, fields);
return { handled: true, resource: summarized ? out : spendLimit };
} else {
// List spend limits with pagination
logDebug('Fetching spend limits list');
const queryParams = parseQueryParams(uri);
const spendLimitsResponse = await brexClient.getSpendLimits({
cursor: queryParams.cursor,
limit: queryParams.limit ? parseInt(queryParams.limit, 10) : undefined,
parent_budget_id: queryParams.parent_budget_id,
status: queryParams.status as any,
member_user_id: queryParams.member_user_id
});
const qp = parseQueryParams(uri);
const fields = qp.fields ? qp.fields.split(',').map(s => s.trim()).filter(Boolean) : undefined;
const summaryOnly = qp.summary_only === 'true';
const summarized = summaryOnly || estimateTokens(JSON.stringify(spendLimitsResponse)) > 24000;
const projected = fields && fields.length ? spendLimitsResponse.items.map((b: any) => project(b, fields)) : spendLimitsResponse.items;
return { handled: true, resource: summarized ? { ...spendLimitsResponse, items: projected } : spendLimitsResponse };
}
} catch (error) {
logError(`Error handling spend limit request: ${error instanceof Error ? error.message : String(error)}`);
throw error;
}
});
};
export default registerSpendLimitsResource;
function project(src: any, fields?: string[]): any {
if (!fields || !fields.length) return src;
const out: any = {};
for (const f of fields) {
const parts = f.split('.');
let cur: any = src;
for (const p of parts) { cur = cur?.[p]; if (cur === undefined) break; }
if (cur !== undefined) {
let o: any = out;
for (let i = 0; i < parts.length - 1; i++) { o[parts[i]] = o[parts[i]] ?? {}; o = o[parts[i]]; }
o[parts[parts.length - 1]] = cur;
}
}
return out;
}
