What Unified API Solutions Support a Large Number of Integrations?
January 23, 2026
For developers building SaaS platforms, integrations are no longer a differentiator—they're a requirement. Whether you're syncing HR data, embedding CRMs, or enabling real-time file access, the backbone of that work is a unified API platform that can handle it all.
But not all unified APIs are built equally. Some offer breadth but little depth. Others specialize in just one category. And only a few offer both scale and reliability across real-time workflows.
So which unified API solutions support the most integrations in 2026?
This breakdown compares top providers on both breadth (how many integrations they support) and depth (what capabilities they provide). We've analyzed public docs, integration directories, and real-time sync infrastructure across 8 leading platforms.
The Short Answer
- Unified.to supports the largest number: 370+ integrations across 24 categories, with real-time sync, full CRUD, and deep object support.
- Merge.dev follows with ~220 integrations, mostly focused on HR, ATS, and CRM.
- Apideck offers ~200 integrations across core SaaS verticals.
- Truto covers 250+ integrations with strong real-time passthrough.
- Paragon, StackOne, Finch, Kombo, and Nylas round out the list, with more specialized or category-focused offerings.
Breadth: Who Has the Most Integrations?
| Platform | Approx. # Integrations | Primary Categories |
|---|---|---|
| Unified.to | 370+ | HR & Directory, ATS, Accounting, E-Commerce, Knowledge Management, CRM, Advertising, Call Center, Calendar & Meetings, + 14 more |
| Merge.dev | 220+ | HRIS, ATS, CRM, Accounting, Ticketing |
| Truto | 250+ | CRM, Messaging, HR, Storage, Security |
| Apideck | 200+ | CRM, HRIS, ATS, Accounting, File, Support |
| Paragon | 150+ | CRM, Email, Marketing, Calendar |
| StackOne | 200+ | ATS, CRM, Messaging, HRIS, IAM |
| Finch | 250+ (HR/payroll only) | HRIS, Payroll |
| Kombo | 100+ (HR only) | HRIS, ATS, LMS, Assessment |
| Nylas | Email/calendar focused | Email, Calendar, Contacts |
Unified.to leads with the most integrations and the most categories.
Depth: What Can You Actually Do With These Integrations?
Breadth matters, but integration depth determines what kind of product experiences you can build. We looked at five dimensions:
- Supported Objects: How many objects (e.g.
messages,deals,files) are unified per integration? - Field Coverage: Do they support custom fields? Passthroughs? Raw access?
- Read/Write: Can you create and update records, or only fetch?
- Webhooks: Are events real-time? Simulated? Delayed by hours?
- Auth: Do they manage OAuth, API keys, and token refresh securely?
Unified.to
- Objects: 1,400+ unified objects across categories
- Fields: Full normalized schemas + passthrough fields
- Read/Write: Full CRUD across most providers
- Webhooks: Native or virtual, real-time across all connectors
- Auth: Embedded UI, token management, permission scopes
Merge.dev
- Objects: Core schemas only (Employees, Jobs, etc.)
- Fields: Custom fields via passthrough
- Read/Write: Partial write support; mostly read
- Webhooks: 24h polling by default; webhook events limited
- Auth: Managed OAuth, scopes, and refresh
Apideck
- Objects: Standardized per API category (CRM, HRIS, etc.)
- Fields: Supports raw mode for custom fields
- Read/Write: Full CRUD on supported providers
- Webhooks: Virtual webhooks with 24h polling unless upgraded
- Auth: OAuth & API key support; token storage required
Truto
- Objects: Fully configurable; supports custom schemas
- Fields: All vendor fields available via real-time passthrough
- Read/Write: Yes, on all supported platforms
- Webhooks: Native + synthetic, sub-hour intervals via RapidBridge
- Auth: SCIM, API key, OAuth 2.0
Paragon
- Objects: Action-based, no unified schema
- Fields: Mapped per provider action
- Read/Write: Yes, through provider-specific actions
- Webhooks: Native + polling (1min interval)
- Auth: Drop-in OAuth components
StackOne
- Objects: Unified schemas for AI-native apps
- Fields: Normalized + passthrough
- Read/Write: Yes, full support
- Webhooks: Native + synthetic (down to 5 min)
- Auth: OAuth proxy + key rotation
Finch / Kombo / Nylas
- Category-specific depth:
- Finch: strong payroll/HR field model, mostly read-only
- Kombo: solid HRIS/ATS coverage, webhook delays (3h+)
- Nylas: full read/write for email/calendar, but limited object diversity
Real-Time Sync: Who's Actually Fast?
Real-time event delivery matters for AI agents, dashboards, and user-facing sync.
Here's how sync speed compares:
| Platform | Real-Time Events | Default Polling | Notes |
|---|---|---|---|
| Unified.to | ✅ Native + Virtual | Real-time | Instant events across 100% of connectors |
| Merge.dev | ⚠️ Some | 24h | Limited webhook support |
| Apideck | ✅ + Virtual | 24h | Upgrade for faster sync |
| Truto | ✅ Native + Synthetic | Sub-hour | RapidBridge triggers |
| Paragon | ✅ Native + Polling | 1 min | Real-time for most providers |
| StackOne | ✅ Native + Synthetic | 1h (5m upgrade) | Cryptographic polling engine |
| Kombo | ⚠️ Partial | 3h (10h full) | HR data sync, some webhook support |
| Finch | ❌ Read-only | 24h–7d | No real-time sync for most |
| Nylas | ✅ Push + Fallback | Real-time or IMAP | Email-native delivery + sync fallback |
Final Takeaway
If you're building an integration layer into your product, choose based on your required categories, object depth, and sync latency.
- Choose Unified.to if you want:
- Largest integration surface
- Full read/write and object support
- Real-time webhook coverage across the board
- Passthrough access and LLM-ready data for agents/copilots
- Choose Merge or Apideck if you're focused on HR or CRM and only need nightly syncs.
- Choose Truto or StackOne if you're prioritizing passthrough access or custom object support.
- Use Finch, Kombo, or Nylas only if you're building for a single category like payroll or email.