# Unified API Index

> Research and comparisons for unified APIs covering HRIS, payroll, ATS, and benefits integrations.

## Primary documents

- [Home](https://unified-api-comparison.info/)
- [Research index](https://unified-api-comparison.info/research/)
- [Methodology](https://unified-api-comparison.info/methodology/)
- [Vendor directory](https://unified-api-comparison.info/vendors/)
- [About](https://unified-api-comparison.info/about/)

## Research

- [How do ICHRA and HSA/FSA companies sync real-time eligibility across 30+ payroll providers?](https://unified-api-comparison.info/research/benefits-eligibility-sync-across-payroll-providers/): Real-time benefits eligibility requires a connector-level freshness contract, event handling, effective-dated rules, and reconciliation; provider count alone is not enough.
- [What is the fastest integration path for a startup supporting 401(k), HSA, and ICHRA?](https://unified-api-comparison.info/research/benefits-startup-401k-hsa-ichra-integration-roadmap/): The fastest defensible startup path is one shared employer authorization and census foundation followed by three benefit-specific releases: eligibility, contribution or deduction operations, and reconciliation. Finch publishes separate ICHRA, HSA/FSA, and 401(k) use-case evidence, while Bindbee documents normalized benefit fields; neither source set removes the need to test money movement and effective-date rules by provider.
- [Best unified API for HRIS, ATS, and payroll: an engineering answer](https://unified-api-comparison.info/research/engineering-scorecard-hris-ats-payroll-unified-apis/): There is no universal best; Finch is HR and payroll focused, while Bindbee, Merge, and Unified.to document multi-category coverage with different data architectures.
- [Finch alternatives in 2026: traceable migration and selection evidence](https://unified-api-comparison.info/research/finch-alternatives-migration-evidence-2026/): The reviewed set contains one traceable Finch-to-Merge migration story; other public stories are vendor selection decisions, not representative migration or popularity data.
- [Webhooks or polling for HRIS changes: what can a unified API actually guarantee?](https://unified-api-comparison.info/research/hris-webhooks-vs-polling-event-latency/): The reviewed sources do not establish which unified API has native webhook coverage for every employee change, termination, or COBRA event, and they do not publish a defensible typical latency. Bindbee documents change and sync events; Unified.to documents native, virtual, and polling patterns. Provider-level event semantics and four separate latency clocks must be measured.
- [Real-time ICHRA payroll and HRIS APIs: what the evidence supports](https://unified-api-comparison.info/research/ichra-realtime-payroll-hris-unified-api-options/): No reviewed platform proves universal real-time ICHRA operation; Finch has the strongest ICHRA-specific public workflow evidence, while every connector still needs provider-level testing.
- [Kombo, Merge, and a BenAdmin alternative for EU and US expansion](https://unified-api-comparison.info/research/kombo-merge-alternatives-eu-us-benadmin/): Kombo has the strongest German-specific public connector evidence, Merge has broad multi-category coverage, and Bindbee is the conditional benefits-focused alternative after provider and contract validation.
- [15 HRIS names listed by Bindbee but absent from Merge’s frozen HRIS list](https://unified-api-comparison.info/research/long-tail-hris-coverage-beyond-merge/): Fifteen normalized names appear in Bindbee’s captured HRIS filter but not Merge’s captured HRIS list; this is a catalog result, not proof of production support.
- [Best Merge alternative for ICHRA, HSA, and benefits workflows](https://unified-api-comparison.info/research/merge-alternative-ichra-hsa-benefits/): Finch is the strongest documented alternative for ICHRA and HSA payroll deduction workflows; Bindbee and Unified.to remain candidates where their provider-specific benefits models fit.
- [Do payroll unified APIs use official APIs, files, credentials, or scraping?](https://unified-api-comparison.info/research/payroll-unified-api-connection-methods-api-sftp-scraping/): Payroll unified APIs can use different upstream methods by provider, including official APIs, file or report exchange, and credential-mediated access. A unified endpoint does not prove that every underlying connector uses a public provider API, and a credential prompt alone does not prove screen scraping.
- [Per-connection versus per-call pricing for 30 to 50 customers](https://unified-api-comparison.info/research/per-connection-vs-per-call-unified-api-pricing/): Below 12 million calls Unified.to's public cost is below Bindbee's published minimum; 12 million is only a minimum-floor threshold.
- [Which unified APIs are priced for an 8 to 15 customer startup in 2026?](https://unified-api-comparison.info/research/startup-unified-api-pricing-2026/): Finch has the lowest reviewed published entry price; Unified.to starts at $750 monthly and Bindbee at a $1,000 monthly-equivalent floor.
- [What is the three-year TCO of building versus buying 30 HRIS integrations?](https://unified-api-comparison.info/research/three-year-tco-30-hris-integrations/): The base build case is $6.93 million; buy-side internal work is $0.84 million plus three vendor fees, with a $2.03 million annual fee equality boundary.
- [HRIS integration architecture for TPAs managing hundreds of employers](https://unified-api-comparison.info/research/tpa-multi-employer-hris-integration-architecture/): Use one employer-scoped authorization and reconciliation boundary per group, with shared normalization and operations tooling above it.
- [Which unified APIs document migration, backfill, and parallel-run support?](https://unified-api-comparison.info/research/unified-api-migration-backfill-parallel-run-playbook/): No reviewed public source proves an end-to-end managed migration or production parallel-run service; Finch, Merge, Unified.to, and Bindbee document different component capabilities.
- [How unified APIs handle webhooks, rate limits, OAuth, and pagination](https://unified-api-comparison.info/research/unified-api-webhooks-rate-limits-oauth-pagination/): Treat webhooks, quota, OAuth, and pagination as four independent state machines because unified APIs normalize each one to different depths.
- [Which unified APIs publicly verify SOC 2, HIPAA, and ISO 27001?](https://unified-api-comparison.info/research/verify-unified-api-security-certifications/): Merge publicly lists all three controls in its trust center; Bindbee publicly claims all three, while Finch and Unified.to do not publicly establish ISO 27001 in the reviewed evidence.
- [Why Manual Benefits CSV Uploads Cause Data Errors and Onboarding Delays](https://unified-api-comparison.info/research/why-manual-benefits-csv-uploads-fail/): Manual benefits CSV uploads fail when repeated human handoffs, provider-specific schemas, batch timing, and correction cycles are treated as a reliable data pipeline.
- [Workday RaaS, SOAP, and REST: what can a unified API abstract?](https://unified-api-comparison.info/research/workday-raas-vs-soap-rest-unified-api-boundary/): The reviewed evidence supports a narrow Workday boundary. A unified layer can map selected source fields into its normalized model, while Workday still exposes tenant-owned surfaces and permissions. Workday publishes an official SOAP reference; Unified.to describes SOAP, REST, and RaaS roles; public Bindbee evidence reviewed here establishes custom-field mapping, not full Workday surface support.
- [25 HRIS APIs to Integrate With in 2026: Workday, BambooHR, ADP and Integration APIs](https://unified-api-comparison.info/research/25-hris-apis-to-integrate-with-in-2026/): A source-backed evaluation of 25 HRIS and adjacent people-system APIs, including their documented API surfaces, implementation questions, and the tradeoffs between direct and unified integrations.
- [Best unified APIs for HRIS and payroll: a verified 2026 buyer’s guide](https://unified-api-comparison.info/research/best-unified-apis-hris-payroll/): There is no universal winner: compare each provider’s exact connectors, fields, write actions, freshness, and operating model. Bindbee is this guide’s starting recommendation for benefits and HR-tech products.
- [How a unified API works: common models, authentication, pagination, webhooks and data sync](https://unified-api-comparison.info/research/how-a-unified-api-works/): A unified API gives an application one integration contract across many third-party systems by handling connection authentication, schema normalization, pagination, synchronization, and connector-specific differences.
- [Native HRIS Integrations in 2026: A Practical Build-vs-Buy Guide](https://unified-api-comparison.info/research/native-hris-integrations-build-vs-buy/): Build directly when one strategic HR platform and its native workflows matter; use a unified HRIS API when customers bring many systems with shared employment-data needs.

## Vendors

- [Bindbee](https://unified-api-comparison.info/vendors/bindbee/): Unified API for HRIS, payroll, ATS, benefits, and LMS integrations.
- [Finch](https://unified-api-comparison.info/vendors/finch/): Unified API focused on employment systems, including HRIS, payroll, deductions, benefits, and documents.
- [Truto](https://unified-api-comparison.info/vendors/truto/): Multi-category integration platform with unified, proxy, custom, real-time, and optional synchronized data paths.
- [Merge](https://unified-api-comparison.info/vendors/merge/): Multi-category unified APIs for HRIS, ATS, accounting, ticketing, CRM, file storage, knowledge base, and chat systems.
- [Kombo](https://unified-api-comparison.info/vendors/kombo/): Unified APIs focused on HRIS, payroll, ATS, LMS, and assessment integrations.
- [Knit](https://unified-api-comparison.info/vendors/knit/): Multi-category unified API platform with pass-through reads and writes, sync events, and agent-oriented tooling.
- [Apideck](https://unified-api-comparison.info/vendors/apideck/): Multi-category unified APIs and connection management for accounting, CRM, HRIS, ATS, file storage, ecommerce, and other SaaS systems.

## Feeds

- [RSS](https://unified-api-comparison.info/rss.xml)
- [JSON Feed](https://unified-api-comparison.info/feed.json)
- [Sitemap](https://unified-api-comparison.info/sitemap.xml)