You will get a custom Chrome or Firefox browser extension, AI optional
Project details
I build browser extensions for Chrome and Firefox, and I've shipped them before, so this isn't new ground for me. You give me a clear brief and I turn it into a working extension: a popup tool, something that reads or changes the pages you use, or an extension with a real AI feature behind it.
The build is straightforward. Manifest V3, TypeScript, tight permissions (only what the feature needs), settings that persist, and one codebase that runs on both Chrome and Firefox. If you want AI, I wire it to Claude or OpenAI through a serverless proxy deployed to your own account, so your API keys never sit inside the extension where anyone can pull them out. Responses stream in as they generate, and I add cost handling so a heavy user can't run up a surprise bill.
A bit of background: I build production AI features and API integrations full time. I shipped a Claude-powered mobile app that uses exactly this proxy pattern, and I built a multi-tenant SaaS solo. I work fully async: written updates at each milestone, no meetings.
Tell me what the extension should do and I'll tell you exactly how I'd build it.
The build is straightforward. Manifest V3, TypeScript, tight permissions (only what the feature needs), settings that persist, and one codebase that runs on both Chrome and Firefox. If you want AI, I wire it to Claude or OpenAI through a serverless proxy deployed to your own account, so your API keys never sit inside the extension where anyone can pull them out. Responses stream in as they generate, and I add cost handling so a heavy user can't run up a surprise bill.
A bit of background: I build production AI features and API integrations full time. I shipped a Claude-powered mobile app that uses exactly this proxy pattern, and I built a multi-tenant SaaS solo. I work fully async: written updates at each milestone, no meetings.
Tell me what the extension should do and I'll tell you exactly how I'd build it.
Programming Languages
JavaScript, Python, TypeScriptCoding Expertise
Cross Browser & Device Compatibility, Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$600
|
Standard
$1,500
|
Advanced
$3,000
|
|---|---|---|---|
| Delivery Time | 7 days | 14 days | 21 days |
Number of Revisions | 2 | 3 | 4 |
Number of Pages | 1 | ||
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code |
Optional add-ons
You can add these on the next page.
Add one AI feature to the Full tier
(+ 1 Day)
+$1,000
Extra browser support
(+ 2 Days)
+$250
30-day async support retainer
+$400Frequently asked questions
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PG
Penny G.
Aug 27, 2025
Webflow website addition
About Veldin
Senior Product Engineer | AI, API Integrations, Full-Stack SaaS
Sarajevo, Bosnia and Herzegovina - 3:57 am local time
The proof, public and clickable:
→ Led the Adobe Marketo Engage app and built the ActiveCampaign app — Marketo is Approved by Webflow and Enhanced-Security certified.
→ Contributed to the official Stripe and PayPal Webflow apps.
→ Built most of Webflow's integration for Slack's MCP launch — Webflow was one of 20+ launch partners alongside Atlassian, Canva, Linear, and Zoom.
I also ship complete products solo, from architecture to deployment:
→ Cloudless — an AI mobile app with a Claude-powered coach behind a secure serverless proxy (React Native)
→ Synqo — a multi-tenant workforce SaaS built solo (auth, scheduling, payroll, real-time dashboards)
→ Dora.ba — a live e-commerce + booking platform (260 products, 118 services)
What I'll build for you:
→ AI features — LLM integrations, AI agents, automation — in new or existing products
→ API & platform integrations — OAuth, webhooks, third-party APIs
→ Full SaaS builds — auth, billing, dashboards, multi-tenant
→ Web & mobile — Next.js, React, React Native
How I work: give me a clear scope and you get it shipped — fast, self-directed, fully async, with written updates at each milestone. No standups or daily syncs (a one-off scoping chat is fine). I'm newer to Upwork than to shipping — most of my work has been senior in-house and direct-client, and everything above is public and verifiable.
Stack: Next.js, React, React Native, Node.js, TypeScript, Python, Postgres/Supabase, Stripe, OAuth/webhooks, Claude/OpenAI.
Portfolio: veldin-portfolio.vercel.app
Steps for completing your project
After purchasing the project, send requirements so Veldin can start the project.
Delivery time starts when Veldin receives requirements from you.
Veldin works on your project following the steps below.
Revisions may occur after the delivery date.
Scope and spec
You send the brief, I confirm the features, browsers, and permissions in writing. One async back-and-forth locks exactly what gets built. No call needed.
Build
I build the extension on Manifest V3, wiring the popup, content scripts, and any API or AI feature. You get a written update at each milestone, so you always know where it stands.