Semrush

Yes. Semrush states that requests made through MCP use the same API units as direct API requests, and that there are no additional MCP usage fees. Units are charged per line for reports such as domain keyword lists and at a fixed price per request for others, so cost scales with how much data your agent asks for rather than how many questions you ask.

Semrush names six routes. Semrush One Starter, Semrush One Pro+, SEO Classic Pro and SEO Classic Guru include MCP with 50,000 API units that refresh on your renewal date. SEO Classic Business and Semrush One Advanced need an API units package added on. Traffic and market data needs a separate Trends API subscription, on which MCP access is included on both Basic and Premium.

No. Semrush states the MCP server exposes only read-only methods from the Projects API, so you can pull data from existing projects but cannot create new ones, modify settings or perform other actions. The Projects API itself does document create, update, delete and run-audit methods, but those sit outside the surface the connector reaches, so no crawl can be launched through it.

Requests fail or return partial data rather than billing you more. Semrush documents ERROR 132 for the SEO API, Trends API, Position Tracking and Site Audit when units are insufficient, and an HTTP 403 for the Projects API and Local API. For SEO and Trends reports priced per line, you instead receive only the number of lines your remaining balance covers, so data can be silently truncated.

One month, unless Semrush agrees otherwise in writing. Its API usage restrictions state you cannot cache information received via the API for more than one month without Semrush's express written consent, and point to section 3.3 of the Semrush Terms of Service. That constraint applies to MCP responses because MCP is a front end over the same APIs, and it rules out building a permanent local warehouse.

Yes. Semrush documents an API key as an alternative for clients that do not support OAuth, passed in the Authorization header in the form Apikey followed by your key. OAuth is the default and needs no headers at all — the agent registers itself and redirects you to the Semrush login page. Our unauthenticated probe on 2026-08-18 saw only the OAuth challenge.

Ten requests per second and ten simultaneous requests per account, which Semrush applies to any request against any of its API methods. The Trends API adds a monthly request quota set by your subscription plan, spendable at any pace inside that same 10 requests-per-second ceiling. Semrush states the older daily and hourly Trends limits have been removed and remain in responses only for backward compatibility.