Engineering guides
API integration project checklist for business teams
Methodology: An original scoping worksheet for business buyers, informed by our own integration and portal engineering. The worked example is illustrative, not a customer case study. Provider-specific advice is linked to official documentation.
Download a pack you can send with a procurement brief
The original integration scope and acceptance pack turns this guide into five reusable files: a field-ownership map, eight failure-acceptance cases, a proposal-comparison worksheet, a synthetic CRM-to-ERP handoff and instructions. No signup is required. Cases start NOT RUN, so a completed design example cannot be mistaken for a passed implementation test.
Ask each candidate to scope the same products, editions, first handoff, record volume and exception policy. Compare native connectors, workflow platforms and custom API integration delivery against the same acceptance boundary. The pack supplies no universal price, compatibility certification or customer benchmark. Use disposable fixtures and keep sensitive evidence private.
For the sales-to-operations boundary, use the worked CRM/ERP field ownership map and CRM/ERP integration scope. If the source is a PDF or scanned form, the document-processing pilot protocol separates extraction, review and verified destination results.
Before commissioning an API integration, agree which system owns each field, what triggers a change, how quickly it must arrive and how an operator will recover a failure. A successful connection test proves that two systems can communicate. It doesn't establish that the right records will stay consistent when requests are delayed, repeated or rejected.
Use this checklist to compare proposals for connecting a CRM, website, support desk or internal application. If you already need delivery help, our API integration and workflow automation service covers scoping, implementation and agreed handover. Start with one complete workflow rather than every possible connection.
Choose the connection you actually need
| Job | What it does | Question to settle first |
|---|---|---|
| Event-driven automation | An event in one system starts a defined action in another. | What happens when the same event arrives again? |
| One-way synchronisation | One system supplies selected fields to another, on a schedule or after a change. | Which system is authoritative, and how old may the destination data be? |
| Two-way synchronisation | Changes can travel in both directions. | How are conflicts, deletions and update loops resolved? |
A built-in connector may already cover the job. A workflow platform can fit a bounded process if its permissions, execution limits and recovery controls meet your needs. Custom engineering becomes a candidate when the required mapping, approvals, volume or operational controls don't fit those options. Check the actual plan and API permissions before choosing a tool. A vendor logo on a proposal doesn't establish compatibility.
Write a data contract before estimating the build
- Name the source and destination, account owner and API plan. Share documentation links, never passwords or API keys in an enquiry.
- List the business objects involved, such as contacts, companies or support requests. Select only the fields the workflow needs.
- Choose a stable record identifier and a matching rule. Decide what happens if no match exists or several records match.
- State field ownership separately. The CRM might own the assigned salesperson while the support desk owns the ticket status.
- Define empty values, dates, time zones, currency units and allowed statuses. Agree whether deletion means archive, unlink or permanent removal.
- Separate the initial historical import from ongoing changes. Give both a validation and rollback plan.
Specify failures as part of the scope
Providers have different delivery and retry rules. For example, Stripe's webhook guidance warns that events can be duplicated and delivered out of order. GitHub's webhook guidance documents a delivery identifier that stays the same during redelivery. These are provider-specific details to verify, not a universal promise that every API offers the same protection.
| Scenario | Required decision | Evidence to request |
|---|---|---|
| Repeated event | Define the business action that must not run twice and how long deduplication evidence is retained. | Send the same test event twice and inspect the saved destination record. |
| Out-of-order update | Define version or freshness rules so an older event can't overwrite a newer state. | Deliver two fixture updates in reverse order and inspect the final state. |
| Rate limit or temporary outage | Set bounded retries, backoff, alerting and an eventual stop condition. | Show a deferred operation, its next attempt and the operator's recovery path. |
| Response lost after a write | Read the saved operation and provider state before considering another write. | Keep the original operation reference and show a result check without resubmission. |
| Invalid or unmatched data | Hold the record for review rather than silently guessing or discarding it. | Show the rejected fields, safe correction and audit history using test data. |
| Expired authorisation | Identify who reconnects the account and what happens to waiting work. | Demonstrate the reconnect instructions without exposing credentials. |
Don't accept an exactly-once guarantee based only on a disabled submit button or one successful test. The scope must explain the provider's idempotency support, concurrent requests, retention window and lost-response behaviour. Where the provider can't establish a result safely, an uncertain operation should stop for review.
Worked example: website enquiry to CRM
A success notice on a form, an email accepted by a mail provider and a CRM record are separate pieces of evidence. Decide which saved result counts as receipt and which confirms the handoff. For account-specific documents and permissions, use the companion client portal acceptance checklist.
Reusable integration brief
| Item | What to provide |
|---|---|
| Business outcome | The manual handoff to replace and the person responsible for its result. |
| Systems and access | Product names, plan names, documentation and available sandbox accounts. |
| Data and ownership | Objects, required fields, stable identifiers and the authoritative source for each field. |
| Direction and timing | Trigger, polling or batch schedule, acceptable delay and peak volume. |
| Exceptions | Duplicates, conflicts, invalid records, outages, deletion and uncertain results. |
| Acceptance | Allowed and denied actions, expected saved state and who signs off using test fixtures. |
| Handover | Account ownership, monitoring, recovery instructions, maintenance scope and code ownership. |
Ask proposals to separate discovery, historical import, ongoing sync, operational handover and maintenance. Cost depends on API access, mapping complexity, volume and failure controls. A single connector demonstration isn't a reliable estimate for an entire business process. Compare the proposed boundaries and evidence, not just the number of platforms listed.
Turn the brief into a useful first conversation
Send StackEndBox the two systems, the workflow you want to improve, approximate volume and the most costly failure today. We'll use that context to discuss whether an existing connector, workflow tool or custom integration fits. Keep secrets and private records out of the first message. We work remotely with international teams and agree availability, ownership and acceptance before implementation.
Continue with API integration services, custom CRM development or AI automation services if reading, classification or drafting genuinely needs a model. The AI agents versus automation guide explains when fixed rules are the simpler choice.