API Integration
API Integration Services That Connect Your Systems
API integration connects separate software systems so data moves between them automatically instead of being re-typed, exported to spreadsheets or synced overnight.
It is for companies whose operations depend on several vendors and tools, such as CRMs, ERPs, payroll, payments, e-signature or shipping carriers, and whose teams are losing time reconciling them by hand.
Peregrine designs and builds the integration layer: adapters for each external API, a normalized internal data model, webhooks and polling with retry logic, and monitoring so failures are visible before your customers notice them.
At a glance
API Integration at a Glance
| What's delivered | Vendor adapters, a normalized data model, webhooks and polling with retries, reconciliation jobs, monitoring, and public or partner APIs |
|---|---|
| Engagement model | Fixed-scope projects, monthly retainers, or a combination, agreed after the discovery call |
| How it starts | A 30-minute technical discovery call with an engineer |
| Pricing | Pricing is scoped per project after the discovery call. |
| Related case studies | Supply Chain Visibility for Shipment Tracking & Alerts; HR & Payroll SaaS for Mid-Market Companies; Legal Document Automation for Contract Generation & E-Signature |
Fit
Is API Integration the Right Fit?
A good fit when
- Two or more systems hold the same records and staff re-key or reconcile them by hand.
- Your product must connect to many vendors of the same kind, such as carriers, payroll providers or MLS boards, and present one model to your users.
- An existing integration loses or duplicates records and nobody notices until a customer does.
- You need to offer your own API to partners or customers.
Probably not the right fit when
- Both systems are covered by a native connector or an automation tool, and volumes are low. That route is cheaper than custom code.
- One system has no API and no export, and its vendor will provide neither. Access has to be resolved before any build.
What we build
What Does Peregrine's API Integration Service Include?
Peregrine's API integration service builds the layer between your systems: one adapter per vendor behind a normalized internal data model, webhooks and polling with retry queues, reconciliation jobs, and monitoring. It covers CRMs, ERPs, payroll and finance tools, e-signature, shipping carriers, and public or partner APIs for your own product.
Integration layers across many vendors
An abstraction layer that hides each vendor's authentication, rate limits and payload format behind one internal schema, so adding the next vendor is an adapter and a config file rather than a change to your core application.
Shown in: Supply Chain Visibility for Shipment Tracking & Alerts
Webhooks, polling and retry queues
Event ingestion that works whichever way the vendor supports it, with deduplication, exponential backoff and dead-letter handling so a vendor outage delays data instead of losing it.
Shown in: Supply Chain Visibility for Shipment Tracking & Alerts
Finance, payroll and HR integrations
Syncing deductions, ledger entries and employee data with providers such as ADP and QuickBooks, with reconciliation reports so mismatches are caught before a pay run.
E-signature and document workflows
DocuSign envelope creation, signing order and webhook callbacks wired into your own records, with a complete audit trail of who signed what and when.
Shown in: Legal Document Automation for Contract Generation & E-Signature
Public and partner APIs
REST or GraphQL APIs for your own product, with authentication, rate limiting, versioning and documentation that partners can build against.
Industries: Real Estate & Proptech · Self-Storage · Logistics & Supply Chain · Healthcare & Insurance · HR, Payroll & Recruitment · E-Commerce, Marketplaces & Food Ordering · All industries
Timeline
How Long Does an API Integration Project Take?
Peregrine sets the timeline for an API integration after mapping every system involved: its authentication, endpoints, rate limits, webhook support and data formats. The number of vendors and the quality of their sandboxes drive the schedule. Work then runs in two-week sprints with weekly demos, and rollout starts with a pilot group.
Map the systems
We document every API involved: authentication, endpoints, rate limits, webhook support and data formats, and agree on the canonical data model.
Build adapters
One adapter per external system, each with its own retry and rate-limit handling, tested against the vendor's sandbox where one exists.
Reconcile and monitor
Reconciliation jobs and alerts that compare what each system believes, so silent drift becomes a visible exception.
Roll out gradually
Pilot with a subset of accounts or records, compare results with the old process, then switch over.
Scope
What Determines the Scope of an API Integration Project?
These are the inputs that change the effort. None needs a final answer before the first call, but each one you can answer makes the estimate tighter.
- Number of systems
- Each system is its own adapter. The effort per system depends on its API documentation, authentication and whether a sandbox exists.
- Direction and ownership
- One-way sync is far simpler than two-way. Two-way needs a rule for which system owns each field and how conflicts are settled.
- Volume and timing
- Records per day, and whether changes must arrive in seconds (webhooks) or can wait for a batch, decide queueing and rate-limit handling.
- Failure handling
- What must happen when a system is down: retries, duplicate protection and a reconciliation job that makes silent drift visible.
- Data mapping
- How different the two data models are, and whether records can be matched when the systems share no identifier.
- Vendor access
- Partner programs, API keys and approvals are granted by the vendor on the vendor's schedule.
A sensible first phase
A sensible first phase is one system and one record type moving in one direction, with retries and a reconciliation report. It proves access, data quality and error handling before the remaining systems are added.
Cost
What Does API Integration Cost?
Peregrine works on API integration as fixed-scope projects, monthly retainers, or a combination, agreed after the discovery call. Cost depends on how many systems are involved and how reliable their APIs are. A single, well-defined integration can get a scoped estimate. For CRM build-or-buy economics, see Building Reliable Webhook and Event-Driven Integrations.
Building Reliable Webhook and Event-Driven Integrations
How to receive and send webhooks reliably: signature checks, idempotency, ordering, retries with jitter, the outbox pattern, reconciliation and SSRF defenses.
Read the guideCustom SaaS vs Off-the-Shelf CRM for Brokerages
When a brokerage should subscribe to a real estate CRM and when a custom platform makes sense, with published CRM pricing and the trade-offs of building.
Read the guideGetting started
How Does an API Integration Project Start?
A Peregrine API Integration project starts with a 30-minute technical discovery call with an engineer, not a salesperson. Larger builds then begin with a discovery sprint that maps requirements, designs the architecture and produces a written technical plan. Smaller, well-defined tasks can use the quick project form for a scoped estimate.
What to bring to the scoping call
- The list of systems, their API documentation, and whether you hold sandbox or test accounts.
- For each record type: which system owns it and which direction it should move.
- Volumes: records on a normal day and on the busiest day.
- A few real sample records from each system, anonymized if needed.
- What happens today when the systems disagree, and who fixes it.
- Any vendor approval or partner agreement that is in place or still needed.
Partial answers are fine. Whatever is missing becomes the first item on the call.
Case studies
Which Case Studies Show Peregrine's API Integration Work?
Three published case studies show Peregrine's API integration work: a supply chain platform normalizing 12 carrier APIs with retry queues and per-carrier rate limits, an HR and payroll SaaS integrated with ADP, QuickBooks and DocuSign, and a legal document platform whose DocuSign webhooks keep multi-party signing moving during outages.
Supply Chain Visibility for Shipment Tracking & Alerts
A carrier abstraction layer normalizing 12 carrier APIs, with webhook and polling ingestion, per-carrier rate limiting and a retry queue with exponential backoff.
Read the case studyHR & Payroll SaaS for Mid-Market Companies
Payroll integrations with ADP and QuickBooks for deductions and ledger export, plus DocuSign for I-9 and W-4 forms, with reconciliation webhooks.
Read the case studyLegal Document Automation for Contract Generation & E-Signature
DocuSign integration for multi-party signing with webhook handlers for envelope events and retries that keep in-flight documents moving during outages.
Read the case studyStack
Technology We Use
Related services
Services Often Scoped With API Integration
FAQ
Frequently Asked Questions
Should we use a no-code tool like Zapier or build a custom integration?
For low-volume workflows between popular SaaS tools, a no-code tool such as Zapier or n8n is often the fastest and cheapest option, and we build those too. A custom integration makes sense when volume is high, when you need retries and reconciliation you can trust, or when the data feeds a core product your customers rely on.
What happens when a vendor's API goes down?
A well-built integration treats outages as normal. Calls that fail go to a retry queue with exponential backoff, incoming events are deduplicated when the vendor resends them, and an alert fires if a backlog grows. Work already in progress continues once the vendor recovers.
Can you integrate with a system that has no API?
Often, yes. Options include scheduled file exchange (CSV or SFTP), database-level replication where the vendor allows it, or email parsing. They are less real-time than an API, so we agree on the delay that is acceptable before choosing one.
How do you keep data consistent across systems?
We define one canonical data model, decide which system is the source of truth for each field, and run reconciliation jobs that compare records and flag differences. That turns silent drift into a list of exceptions someone can act on.
Do you build APIs for our own product as well?
Yes. We design REST or GraphQL APIs with authentication, rate limiting, versioning and documentation, so partners and customers can integrate with your platform.
Who owns the IP rights to what Peregrine builds?
You do. Once the work is paid for, the client owns the intellectual property (IP) rights to what Peregrine builds for the project, whether it is delivered as a fixed-scope project, a monthly retainer or a combination of the two.
Questions about the team, contract models and how progress is shown are answered on the services page.
Technical consultation
Talk to an Engineer About API Integration
Tell us what you are building or fixing. Your first conversation is with an engineer, not a salesperson.
- A 30-minute technical discovery call with an engineer, not a salesperson.
- Fixed-scope projects, monthly retainers, or a combination, agreed after the call.
- Small, well-defined tasks get a scoped estimate. We reply within 1 business day.
Prefer to pick a time? Book a call on Calendly
