Half-done integrations, webhooks that never arrive and vendor docs that skip the hard parts slow every product down. We implement the third-party API or webhook in your app, handle authentication, signature verification, errors and retries, and test it end to end with real events.
Is this your problem?
An integration with Stripe, HubSpot, Salesforce, Twilio, Shopify or another service is half-done.
Webhooks are not arriving, arrive twice or fail signature checks.
The vendor's documentation skips the parts you are stuck on.
Data between your app and the third-party service is out of sync.
Why this happens
Integrations break in the details: webhook signature verification, OAuth and token refresh flows, payload formats that differ from the docs, missing idempotency so events are processed twice, and no retry logic when the vendor or your server is briefly down. These problems rarely show up in a quick test but appear as soon as real events start flowing.
What we do
Review the vendor API and your current code.
Implement the integration — authentication, requests and webhook endpoints.
Verify signatures and make event handling idempotent.
Handle errors and retries so no event is lost.
Test end to end with real events in test or sandbox mode.
What you get
Working integration in your codebase
Test evidence showing real events processed correctly
Setup notes for keys, environments and going live
What we need from you
The vendor's API docs and test-mode keys
Access to your repository
A short description of what data should flow where
Common cases we handle
Stripe, PayPal and Razorpay payments and webhooks
HubSpot, Salesforce and Zoho CRM sync
Twilio, WhatsApp and SendGrid messaging
Shopify, Slack, Google Workspace and custom REST or GraphQL APIs
Pricing and turnaround
Starting price | From $49 |
Delivery | Typically 24h |
Priority delivery | 12h for +50% |
Includes | Scope check, the work, deliverables and handover notes |
Every task gets a fixed price, confirmed after the free scope check. Your code and data are used only for this task, and we sign an NDA on request.
How it works
Submit your task. Tell us what you need and share the files or access listed above.
Free 30-minute scope check. An engineer confirms the scope and gives you a fixed price before any work starts.
We do the work. Your task is handled by Codersarts' own engineering team — not a freelancer marketplace.
Delivery and handover. You get the deliverables, a walkthrough of what changed, and time to ask questions.
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Need more than a single task?
For a full integration layer or a larger build, see Codersarts Build Solutions.
FAQ
How much does an API integration cost?
From $49 for a Standard Task. The fixed price is confirmed after a free 30-minute scope check.
How fast will it be done?
Typically 24 hours. Priority 12-hour delivery is available for +50%.
Do you need my live API keys?
No. We build and test with test-mode or sandbox keys, and the setup notes explain how to switch to live.
Which APIs do you work with?
Any documented REST or GraphQL API, including Stripe, HubSpot, Salesforce, Twilio, Shopify and Slack.
Is my code confidential?
Yes. Access is used only for this task, and we sign an NDA on request.
Prefer to learn it yourself? Explore hands-on courses at Codersarts Labs.