CRM with a good API so developers can connect it to our product

If you want a hosted CRM that’s straightforward for developers to connect to your product, I’d start with HubSpot.

• HubSpot — best default: Broad CRM APIs and established developer tools; its current published limits vary by plan, so check the tier you’d actually use. (legal.hubspot.com)
• Pipedrive — simpler sales CRM: Offers a REST API, webhooks, and developer resources; a good fit if your integration centers on sales contacts and deals. (pipedrive.com)
• Salesforce — most extensible, more involved: Its API lineup includes REST, bulk, GraphQL, and other options, which is useful for complex or large-scale integrations—but may be more than you need. (help.salesforce.com)
• Zoho CRM — worth considering for a broader toolkit: It has REST, bulk, composite, and notification APIs, though I’d test the exact integration flow before committing. (zoho.com)

My quick take: Pick HubSpot for a general-purpose integration, Pipedrive for a focused sales workflow, or Salesforce if you expect deep customization and enterprise requirements.

Before deciding, test your must-have operations—OAuth, custom fields, webhooks, and rate limits—on the plan you’d buy. If you tell me what your product needs to read or write, and whether customers will connect their own CRM accounts, I can narrow this down.

The best fit depends on whether you're syncing data with customers' CRMs or building CRM features into your own product. Based on current reviews, these are the strongest options:

• HubSpot is the most common pick for developers. Its API is included on every account, including the free CRM, and it has a broad object catalogue and good docs. One caveat: Free and Starter portals allow 100 requests per 10 seconds, so plan for rate limits as you scale. Marketplace integrations like Gong or Clari can add $500–$2K/month, which matters if you need those.

• Attio is the most modern API-first option. One review calls it the cleanest modern REST API with a public OpenAPI spec and the most production-ready webhooks. It also offers full API and webhook access on every plan, including the free one. Its ecosystem is smaller than the incumbents'.

• Pipedrive is simple and predictable. Its REST API is straightforward with predictable CRUD patterns. Watch the limits: API requests consume tokens from a daily company budget that resets every 24 hours. Also, API tokens are scoped per-user, not per-app.

• Salesforce has the deepest API surface, with REST, SOAP, Bulk, and Streaming options, but it's the most expensive route. Its API access costs an extra US$25 a user a month on Pro Suite, and it has a steeper learning curve.

• Zoho CRM is a lower-cost enterprise alternative, with a comprehensive API with high rate limits on paid plans.

• Twenty (open source) is worth considering if you want to self-host or control the data model. Its GraphQL API covers all objects, including custom ones, and supports real-time subscriptions.

My suggestion: for a general-purpose product, start with HubSpot if you want the largest ecosystem and free API access, or Attio if you want the cleanest developer experience and don't need a big marketplace. Choose Salesforce only if your customers are already on it.

Before committing, I'd check:

1. Your expected API call volume against each vendor's current limits, since these change often.
2. Whether your customers already use a specific CRM, because building connectors for their CRM may matter more than picking the best API.
3. Current pricing on vendor sites. Much of the comparison data comes from third-party blogs.

If you tell me your expected scale, budget, and whether you're building a sync or embedding CRM features, I can narrow this down.

For developers looking to connect a product to a CRM, the "best" choice depends on whether you need a direct, code-first integration with a specific platform or a unified API that abstracts away the complexity of multiple CRMs.

1. Top CRMs with Developer-Friendly APIs

If you want to build a direct integration with a specific CRM, these are widely considered the most developer-friendly due to their documentation, SDKs, and endpoint reliability.

• HubSpot: Frequently cited as the gold standard for developer experience. It offers a comprehensive REST API, official SDKs in multiple languages (Node.js, Python, PHP, etc.), excellent documentation, and a free developer sandbox.
• Pipedrive: Highly regarded for its straightforward, predictable API. It is often preferred by teams that want a clean, no-nonsense integration without the complexity of enterprise-heavy platforms.
• Salesforce: The most powerful and extensive option. While it has a steeper learning curve, it offers unparalleled depth. It is the best choice if you need to support complex enterprise workflows, custom objects, and deep data mapping.
• Attio: A modern, data-model-first CRM that is increasingly popular with ops-heavy teams for its flexible API design.

2. Unified API Platforms (The "Build Once" Approach)

If your product needs to connect to multiple different CRMs (e.g., Salesforce, HubSpot, Zoho, and Microsoft Dynamics) for your customers, building direct integrations for each is a significant maintenance burden. Unified APIs allow you to build one integration that works across many CRM providers.

• Nango: A top choice for "code-first" teams. It manages authentication and data syncing while still providing you with full API access and the ability to write custom logic per integration.
• Merge: Excellent if you want broad, standardized coverage across many CRM platforms without needing to manage the nuances of custom objects or deep field mapping.
• Ampersand: Highly recommended if you require "deep" integrations (e.g., bidirectional writes, custom objects) where you want to treat the integration as versioned code.
• Grid Squid: Specialized specifically for CRM connectivity, often noted for deep support of custom objects and bulk operations.

Summary Recommendation

Developer Checklist for Evaluation

Before committing to a CRM, ensure your engineering team checks these "boring" details, which will save you hundreds of hours later:

• Webhooks: Can the CRM notify your server of events (e.g., "deal updated") in real-time?
• Sandbox Access: Does it offer a free, isolated environment for testing?
• Rate Limits: Are the limits documented and high enough for your expected volume?
• Custom Objects: Can you sync custom data models if your product requires it?

HubSpot is the best default if you want a capable CRM that’s straightforward to connect to a product. Its APIs cover common CRM data—contacts, companies, deals, tickets, and custom objects—and support searching, associations, and pipelines. ¹⁴⁹

Other good fits:

• Pipedrive — worth considering if you mainly need a sales pipeline. It offers a REST API, webhooks, SDKs, and an OpenAPI spec, which can make development and testing convenient. ³¹³
• Salesforce — a strong option for complex, highly customized enterprise workflows. Its REST API supports standard record operations, queries, search, and metadata, but it may be more than you need for a simple integration. ¹¹

Quick pick: Start with HubSpot for a general-purpose product integration; choose Pipedrive for a focused sales CRM, or Salesforce for extensive enterprise customization. Before committing, check the specific API limits, authentication options, and plan requirements for the features you need.