01
Public and partner APIs
Versioned, documented APIs with authentication and rate limits.
ServicesAPI development and integration
API development and integration
API Development and Integration Services
Most operational pain lives between systems: the CRM that disagrees with billing, the ERP nobody can query, the partner who needs data you can't export. ResoluteX designs APIs your partners can build against and integrations that keep systems in agreement.
Systems that agree with each other, connected through contracts that are documented and tested.
Where this work fits
02
System integration
Keep CRM, ERP, billing and support data consistent with tested sync jobs and webhooks.
03
Legacy wrapping
Put a clean API in front of a system nobody wants to touch.
04
AI-ready interfaces
Expose data and actions cleanly so agents can use them safely.
What you receive
- 01API specification (OpenAPI) and documentation
- 02Implementation with authentication, validation and rate limiting
- 03Contract and integration tests
- 04Monitoring and error handling for every integration
- 05Source code and a handover
How delivery works
- 01
Map the data flow
Which system owns which record, and where they disagree today.
- 02
Design the contract
The API or sync contract is written and agreed before code.
- 03
Build and test
Contract tests prove each side behaves as agreed.
- 04
Monitor and hand over
Alerts for failures and documentation for whoever runs it next.
A good fit when
- Teams re-key data between systems by hand
- Partners or customers need programmatic access
- An integration breaks silently and nobody notices for days
Probably not the right fit when
- An off-the-shelf connector already does exactly what you need
- The source systems offer no way to read or write data
- You need a full ERP replacement
Questions buyers ask
Before you scope the work
How much does API development cost?
Fixed milestones start at $2.9k; the scope depends on the number of systems, endpoints and data volume.
Which systems can you integrate?
Any system with an API, database access or file export — CRMs like Salesforce and HubSpot, support desks, billing and ERPs. Access is confirmed during scoping.
Do you document the APIs?
Yes — an OpenAPI specification and usage documentation are part of the deliverable.
Who maintains the integrations?
You can own them after handover, or add optional flat-priced support.
Related services
Describe the outcome in one sentence. We will return a fixed sprint plan within one business day.
Scope a sprint