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USD
I will integrate or fix rest apis and webhooks for your backend
Siyu Ren
About this gig
Is an API returning wrong data, failing authentication, or leaving webhooks unprocessed? I integrate and repair scoped connections between backends and third-party systems.
I can help with:
- REST API integration or troubleshooting
- Webhook setup, validation, and delivery
- API Key, Basic Auth, Bearer Token, or agreed OAuth setup
- Request/response mapping and data transformation
- Timeouts, retries, status codes, and error handling
- Postman or cURL verification with sanitized test evidence
I can implement it in Spring Boot, n8n, Supabase, or another compatible backend. This Gig covers integration only, not a complete app, SaaS product, automation system, or full backend build.
Please contact me before ordering with API docs, source and destination systems, authentication method, expected mapping, sanitized errors, and acceptance criteria. Each package covers only the agreed number of APIs or webhooks. Larger or uncertain work requires a custom offer.
Never send passwords, production tokens, private keys, payment information, or real customer data. Use a test environment and revocable, least-privilege credentials whenever access is needed.
Get to know Siyu Ren
Siyu Ren
AI App Troubleshooting and Backend Developer
- FromChina
- Member sinceJul 2026
- Avg. response time1 hour
Languages
Chinese, English
I help founders rescue and stabilize AI-built web apps and backend systems. I diagnose deployment failures, Supabase Auth/RLS problems, API and database bugs, and Spring Boot issues, then deliver tested fixes with clear handover notes. My stack includes Lovable, Bolt, Replit, React, Vite, Supabase, Vercel, Java, Spring Boot, REST APIs, PostgreSQL, MySQL, Redis, and n8n. With 8 years of backend experience, I focus on root-cause analysis, secure access, clear scope, and practical fixes without unnecessary rebuilding.
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FAQ
Can you fix an existing API integration?
Yes. Send the API documentation, sanitized request and response examples, the exact error, and the expected result. I will first confirm whether the issue fits one of the packages or needs a custom offer.
Which authentication methods do you support?
I support API Key, Basic Auth, Bearer Token, and clearly scoped OAuth configuration. Complex OAuth provider review, certification, production approval, or account-owner verification is not included.
Can you work with Spring Boot, n8n, or Supabase?
Yes. I can implement the agreed API or webhook connection in Spring Boot, n8n, Supabase, or another compatible backend environment. This Gig covers the integration only, not a complete backend or automation-system build.
What do you need before starting?
I need the API documentation, source and destination systems, authentication method, required field mapping, sanitized errors or logs, expected result, acceptance criteria, and access to a safe test environment.
Do you support webhooks?
Yes. I can set up or fix inbound and outbound webhooks, verify payloads and signatures when documented, map data, handle delivery errors, and provide sanitized test evidence within the package limit.
What is not included in the packages?
The packages do not include full app or SaaS development, complete backends, complex OAuth approval, full payment systems, large migrations, multi-repository refactors, third-party fees, or unagreed integrations.
How should credentials be shared safely?
Never send passwords, production tokens, private keys, payment information, or real customer data. Use revocable test credentials with minimum permissions, sanitized examples, and a test environment whenever possible.
