API review

Close API review

Calling- and email-first sales CRM for SMB sales teams, with a lead-centric REST API v1 (OpenAPI since 2026-04), advanced filtering, bulk actions, a 30-day event log, webhooks with filters, AI field enrichment and an official remote MCP server. Best for inside-sales teams that call and email from the CRM.

Verified 25 Oct 2026 · 12 endpoints listed · Official MCP server

See pricing

Close API docs

What a call costs

The actions you pay for, as Close prices them.

Action	Cost	Per
Call recording + transcription add-on	$50/month per org + $0.02	per minute
Phone lines (BYOL or rent)	from $1	per line/month
Calling and SMS	passed through at cost; most outbound calls ~ $0.02	per minute
Additional organization	$50 (Growth and Scale include 1 free secondary org)	per org/month

Pricing, plan by plan

US dollars, as Close's pricing page shows them on 25 Oct 2026. Monthly and annual billing are shown apart.

Free tier No free plan. 14-day free trial, no credit card; includes $5 of calling and enrichment credits plus AI credits. Signup requires a phone number and consent to calls/texts (hands-on). Account pauses when the trial ends. 30-day money-back guarantee on paid plans.

Solo

$19/mo

billed monthly

$9/mo

billed annually

limited to 1 user; 500 AI credits/month (refreshes monthly, no rollover; more can be bought)

API included

Plan details

additional AI credits available for purchase (price not published on the pricing page)

Essentials

$49/mo

billed monthly

$35/mo

billed annually

1,000 AI credits per user/month, shared pool up to 10,000/month, no rollover; call recording retention 30 days

API included

Plan details

additional AI credits available for purchase (price not published on the pricing page)

Growth

$109/mo

billed monthly

$99/mo

billed annually

1,500 AI credits per user/month, shared pool up to 15,000/month, no rollover; 1 free secondary org

API included

Plan details

additional AI credits available for purchase (price not published on the pricing page)

Scale

$149/mo

billed monthly

$139/mo

billed annually

2,000 AI credits per user/month, shared pool up to 20,000/month, no rollover; unlimited call recording retention; custom roles; 1 free secondary org

API included

Plan details

additional AI credits available for purchase (price not published on the pricing page)

Rate limits

Per endpoint group (path + method groups).

How to get an API key

Close uses Basic auth. The steps below follow Close's own docs.

Create a Close account. API access starts on the Solo plan.
Settings > Developer > API Keys (scoped to a user/organization pair)
Send it with every request: header: Authorization: Basic base64('<api_key>:') (key as username, empty password); OAuth 2.0 bearer for apps; MCP also accepts headers Close-API-Key + Close-Scope.
Make a first call: Create a lead (company) with nested contacts, addresses, custom fields. Keep the key in an environment variable, never in the command.
```
curl -X POST "https://api.close.com/api/v1/lead/" \
  -u "$CLOSE_API_KEY:" \
  -H "Content-Type: application/json" \
  -d '{}'
```

Where the docs live

What	Where
Documentation	developer.close.com
API reference	developer.close.com/api/overview
OpenAPI spec	developer.close.com/openapi.json
llms.txt	developer.close.com/llms.txt
Changelog	developer.close.com/api/overview/changelog
Base URL	`https://api.close.com/api/v1`
MCP server	`https://mcp.close.com/mcp`
SDKs	Python: closeio/closeio-api (officially maintained by Close), Node.js: closeio/closeio-node (Close's GitHub org), Community: Ruby, PHP (incl. Laravel), C#/.NET, Elixir, Go

Strengths and limits

Where it fits

Inside-sales teams that call and email from the CRM
Change-data sync via the event log (30 days back) and filtered webhooks
Agent access via the remote MCP with read / write_safe / write_destructive scopes
Bulk edits/emails/sequences over a saved search (Smart View or Advanced Filtering query)

Where it falls short

Account-based models: Close's top object is the Lead (a company) with contacts nested inside
Free usage: every plan is paid; 14-day free trial, no card, but signup requires a phone number and consent to calls/texts
Batch record creation: no batch create endpoint in the docs; bulk actions operate on existing leads

Worth knowing

Rate limits are per endpoint group and per key, with the org cap at 3x a single key; per-key numbers are not published (an unauthenticated probe showed 100 per 1-second window on GET /me/), so read the RateLimit header and honour Retry-After on 429. Source: developer.close.com/api/overview/rate-limits
API keys use HTTP Basic with the key as username and an EMPTY password (note the trailing colon). Source: developer.close.com/api/overview/api-key-authentication
Webhook subscriptions silently stop after 3 days of failed delivery (auto-paused) and need an API call to resume. Source: developer.close.com/api/resources/webhooks
Event log only goes back 30 days. Source: developer.close.com/api/resources/events
Only the Python (closeio-api) and Node.js (closeio-node) clients come from Close; the Ruby, PHP, C#, Elixir and Go libraries are community-built. Source: developer.close.com/api/overview/api-clients

2 moreShow fewer

The OpenAPI spec (since 2026-04-06) is marked experimental: Advanced Filtering POST /data/search/ is missing, and create-lead/merge/export bodies are untyped, so use the per-endpoint docs pages for request fields. Source: developer.close.com/api/overview/changelog/2026/4/6
enrich_field via MCP needs the mcp.write_destructive scope, and the REST call is synchronous and may time out on complex guidance. Source: developer.close.com/mcp/tools; developer.close.com/api/resources/field-enrichment

Who should use it

Use Close for: Inside-sales teams that call and email from the CRM
Look elsewhere for: Account-based models: Close's top object is the Lead (a company) with contacts nested inside

If Close is not the answer

Other CRM tools in this directory, each with its own review.

Attio

CRM

Free planOfficial MCP

Best for start-ups and agencies wanting a free/cheap CRM with API, webhooks and MCP on every plan.

Best for google Workspace teams that want a simple CRM inside Gmail.

Copper API review

folk

CRM

From $24/moOfficial MCP

Best for agencies, VCs and founder-led teams that want a simple CRM their agents can write to.

folk API review

Before you build

Four things to settle first, each read off Close's own pages.

Confirm the API is on your planAPI access starts on the Solo plan. Free tier: No free plan.
Keep the key out of your codeBasic auth. It is sent as: header: Authorization: Basic base64('<api_key>:') (key as username, empty password); OAuth 2.0 bearer for apps; MCP also accepts headers Close-API-Key + Close-Scope.
Design around the rate limitPer endpoint group (path + method groups).
Know the catch before you scaleRate limits are per endpoint group and per key, with the org cap at 3x a single key; per-key numbers are not published (an unauthenticated probe showed 100 per 1-second window on GET /me/), so read the RateLimit header and honour Retry-After on 429. Source: developer.close.com/api/overview/rate-limits

Want us to build it for you?

Tell us what you want Close to do in your stack. We will show you how we would wire it into your data, outbound or CRM, and what we would check first.

Book a call

See case studies

Read from close.com/pricing, developer.close.com/api/overview and developer.close.com/api/overview/rate-limits. Verified 25 Oct 2026.

All 12 endpointsFor developers: method, path, what it does and what it costs.

Base URL: https://api.close.com/api/v1

Bulk and async: Bulk actions (edit, delete, email, sequence subscription) over a query or Smart View; async exports. Source: developer.close.com/api/resources/bulk-actions

Webhooks: Yes. POST /webhook/ with url + events[{object_type, action, extra_filter}]; response includes signature_key, payloads signed with HMAC-SHA256 in the close-sig-hash header. Failed deliveries retried with exponential backoff (up to every 20 min) for up to 72 hours; subscription auto-paused (queue cleared) if all deliveries fail for 3 days or the max queue length is reached, admins are emailed, and it must be re-activated via API. Source: developer.close.com/api/resources/webhooks (verified 2026-10-25)

Filter endpoints

12 endpoints

Method	Path	What it does	Cost
POST	`/lead/`	Create a lead (company) with nested contacts, addresses, custom fields	none
POST	`/lead/merge/`	Merge two leads	none
POST	`/contact/`	Create a contact (lead_id optional since 2025-02-14)	none
POST	`/data/search/`	Advanced Filtering: find leads or contacts matching arbitrary criteria (dedupe lookups)	none
POSTasync	`/bulk_action/edit/`	Bulk edit every lead matching a query or Smart View (set status, custom field, etc.)	none
POSTasync	`/bulk_action/delete/`	Bulk delete every lead (or object) matching a query	none
POSTasync	`/bulk_action/email/`	Send a bulk email (template) to every lead matching a query	none
POSTasync	`/bulk_action/sequence_subscription/`	Subscribe/pause/resume every matching contact in a sequence	none
POSTasync	`/export/lead/`	Export leads/contacts/opportunities to a file	none
GET	`/event/`	Event log of object changes, up to 30 days back	none
POST	`/webhook/`	Subscribe a URL to events with optional JSON filters	none
POST	`/enrich_field/`	AI Field Enrichment: fill a custom field on a lead/contact (synchronous; may time out on complex guidance)	docs: 'may consume credits or incur costs' (amount not stated); pricing: AI features draw on plan AI credits (500-2,000 per user/month, no rollover); MCP get_ai_credit_usage reports AI credit use per feature