Close API
Close runs a self-serve REST API with a published OpenAPI spec, API key or OAuth 2.0 auth, webhooks, and an official MCP server. Nearly the full CRM object graph is exposed, though some surfaces sit behind the Scale plan and per-endpoint rate limits throttle heavy syncs.
Frequently asked questions
Close scores C on the API Report Card. Close runs a self-serve REST API with a published OpenAPI spec, API key or OAuth 2.0 auth, webhooks, and an official MCP server. Nearly the full CRM object graph is exposed, though some surfaces sit behind the Scale plan and per-endpoint rate limits throttle heavy syncs.
Close has an official API, but teams routinely hit its limits: gated access, partial coverage, or paid tiers. Most end up supplementing it with exports or an unofficial API layer like Supergood.
Close is an inside-sales CRM that puts multi-channel communication, outbound calling, email, SMS, and WhatsApp, at the core of the product rather than as bolt-ons.
Vertical: horizontal Inside Sales CRM / outbound sales engagement for SMB. Inside-sales reps live in the Inbox and Lead views: Power Dialer queues a list of leads, auto-dials, logs calls and recordings against the lead/opportunity, and pushes call notes into the activity timeline.
Close serves 10,000+ sales teams, has processed 2B+ calls/emails/SMS, holds 4.7/5 on G2, and is a bootstrapped, profitable company that has crossed ~$45M ARR with internal guidance to ~$50M.
Yes, for 10,000+ inside-sales teams, Close is the system of record for the full outbound sales pipeline and activity history.
Founded 2013 by Steli Efti, Anthony Nemitz, and Thomas Steinacher, originally as Close.io (rebranded to Close), spun out of Elastic Sales, a sales-as-a-service shop that ran outbound for ~200 venture-backed startups and needed CRM tooling they could trust.
Rate limits enforced per endpoint group, with per-API-key limits and a per-Organization limit set at 3x the per-key RPS, heavy single integrations can throttle even when org-wide capacity remains. 429 (Too Many Requests) responses require the caller to honor rate_reset and Retry-After headers per RFC 7231, naive clients without backoff/queueing will be throttled hard. Full sourced list under Sources below.
Common alternatives include HubSpot Sales Hub, Salesforce Sales Cloud, Pipedrive, Zoho CRM, Freshworks Freshsales, Apollo.io. Graded alternatives appear under "More from the report card" below.
Grades measure one thing: can a customer's engineering team get their own data out programmatically? We check six things (whether a real API exists, how access is gated, data coverage, auth quality, docs and developer experience, and stability) and roll them into a letter grade. Grades get re-verified, and they only move on evidence.