Best CRMs with an open API
Four CRMs ranked on the plan that unlocks their API, whether webhooks come with it, and whether an MCP server sits beside it.
Want to see it first? Book a demo
Attio ranks first on this method: API access, webhooks and its MCP server are on every plan, free included. Close ranks second, with the API and event log on every tier from $9 per user a month (both checked September 2026).
Our pick for agent and automation access
The short answer
- Attio lists API and webhook access and an MCP server on its Free, Plus, Pro and Enterprise plans, per attio.com/pricing (checked September 2026).
- Close includes API access and an event log on all four plans, from Solo at $9 per user a month (regular $19), per close.com/pricing (checked September 2026).
- Insightly lists its REST public API and webhooks from Professional at $49 per user a month on annual billing, per insightly.com/pricing (checked September 2026).
- SalesCrew gives every tier 140+ MCP tools and outbound webhooks, so agents and tools like n8n reach the full CRM.
How we ranked open CRM APIs
We fixed four criteria first. API access on the entry plan counts 35%. Webhooks on the same plan count 25%. An MCP server beside the API counts 20%. The price of the cheapest plan that includes the API counts 20%, because that's the plan you'll really pay for.
Each vendor row comes from that vendor's own pricing page, read in September 2026. Disclosure: SalesCrew is our product. It sits in the Our pick box, outside the ranked list, because its open surface is 140+ MCP tools and outbound webhooks, and this method scores REST plans.
Where each CRM unlocks its API
| CRM | Entry price | API from | Webhooks | MCP server |
|---|---|---|---|---|
| Attio | Free plan | Every plan, Free included | Every plan | Every plan |
| Close | $9/user/mo (Solo; regular $19) | Every plan, with event log | Event log API on every plan | Yes, mcp.close.com |
| Insightly | $29/user/mo (Plus, annual) | Professional ($49, annual) and Enterprise | Professional and Enterprise | Not listed on pricing page |
| Copper | $23/user/mo (Basic, annual) | Professional ($59) and Business | Not listed on pricing page | Not listed on pricing page |
Checked September 2026 on attio.com/pricing, close.com/pricing, developer.close.com/mcp, insightly.com/pricing and copper.com/pricing.
Where each API fits
Attio
Best for a builder who wants to prototype on a free plan. Attio lists API and webhook access and its MCP server on every plan, so nothing you build breaks when you upgrade (checked September 2026).
Close
Best for a sales team that wants API keys or OAuth from day one. Close ships the API and event log on all four plans, from $9 per user a month (regular $19), and runs an MCP server at mcp.close.com (checked September 2026).
Insightly
Best for a team that wants the REST API and webhooks together on one mid-priced plan. Insightly lists both from Professional at $49 per user a month on annual billing (checked September 2026).
Copper
Best for a team that plans to buy Professional anyway. Not for: a team that needs the API on Basic; Copper lists its API and SDK from Professional at $59 per user a month (checked September 2026).
SalesCrew (our pick)
Disclosure: SalesCrew is our product. Best for a team that wants AI agents and automations to do the work. Every UI action has an MCP twin, webhooks fire on CRM events, and Core is $299 a month for every seat.
Read moreHow to choose a CRM API
Entry-plan access. Check the plan you'll really buy, not the top tier. As of September 2026, Insightly and Copper list their API from Professional, while Attio and Close list it on every plan.
Who writes the code. If an AI client does the work, an MCP server matters more than endpoints. Read MCP vs API for a CRM before you pick. SalesCrew's 140+ tools mean you won't find a UI action an agent can't reach.
Events out. Syncs start with webhooks. SalesCrew sends webhooks with a delivery log and retries, so Zapier, Make or n8n can act on every change. See pricing for what each tier includes.
Questions
- Which CRM includes API access on its free plan?
- Attio lists API and webhook access, plus its MCP server, on its Free plan and every paid plan (attio.com/pricing, checked September 2026). Close's API and event log sit on all four of its plans, from Solo at $9 per user a month (regular $19).
- Do all CRMs include the API on every plan?
- Attio and Close do; Insightly and Copper start it one plan up. Insightly lists its REST public API and webhooks from Professional at $49 per user a month. Copper lists its API and SDK from Professional at $59 (both annual, checked September 2026).
- Is a CRM API the same as an MCP server?
- They reach the same data in different ways. A developer writes code against API endpoints. An MCP server hands an AI client like Claude a set of named tools it can call. Attio and Close offer both; SalesCrew gives you 140+ MCP tools and outbound webhooks.
- What can you build with a CRM API?
- Three jobs cover most builds: syncing records with another system, pushing form leads in, and firing work when a record changes. The first two need write access on your plan. The third needs webhooks, so check both rows in the table above before you buy.
- How do Zapier, Make or n8n connect to SalesCrew?
- Through outbound webhooks and MCP. SalesCrew sends each event to your webhook URL, tracks every delivery, and retries failed ones. Zapier, Make or n8n pick the event up and act on it, and MCP covers the writes back into the CRM.