DEV Community: matengtian

How to Build Your Own AI API Gateway (70x Cheaper Than GPT-4o)

matengtian — Wed, 27 May 2026 11:08:16 +0000

Why I Built This

DeepSeek's API costs ¥1 per million tokens. GPT-4o costs ¥70. That's a 70x difference.

But not everyone wants to deal with API key management, billing, and deployment. So I built a one-command gateway.

What It Does

OpenAI-compatible endpoint — drop-in replacement for any OpenAI SDK
Routes to DeepSeek — 70x cheaper, same quality for most tasks
API key management — generate and manage keys for your team
Usage tracking — see who's using what
Self-hosted — your data, your server

One Command Deploy

git clone https://github.com/matengtian/deepseek-gateway.git
cd deepseek-gateway
pip install -r requirements.txt
DEEPSEEK_API_KEY=sk-your-key python server.py

That's it. You now have an OpenAI-compatible API endpoint.

Use It Like OpenAI

import openai
client = openai.OpenAI(
    api_key="YOUR_GATEWAY_KEY",
    base_url="http://your-server:8080/v1"
)
response = client.chat.completions.create(
    model="deepseek-chat",
    messages=[{"role": "user", "content": "Hello!"}]
)

Pricing Comparison

Service	Per 1M Tokens
GPT-4o	¥70
Claude Opus	¥105
DeepSeek via Gateway	¥1

Open Source + Managed Option

Free: Self-host. MIT license. Use forever.
Managed: ¥10/month. We deploy, monitor, and maintain. WeChat/Alipay available.

Try It

GitHub: https://github.com/matengtian/deepseek-gateway

Managed hosting: http://47.108.162.152/

Built in an hour. MIT license. PRs welcome.

How I Built 8 Free Dev Tools as a Solo Maker — Lessons Learned

matengtian — Wed, 27 May 2026 09:10:08 +0000

The Backstory

I'm a solo developer. No team, no funding, no fancy stack. Just a laptop, Claude Code, and a problem: every online dev tool I used was uploading my data to some server.

So I built my own. Eight of them.

What I Built

Tool	Time
JSON Formatter + CSV export	45 min
Image → Base64 encoder	30 min
SQL Formatter with highlighting	1 hour
Markdown → HTML preview	2 hours
UUID/ULID Generator	15 min
Regex Tester with captures	40 min
Timestamp Converter	20 min
Diff Checker (LCS algo)	1.5 hours

Total: ~7 hours. All client-side. Zero dependencies. Single file under 30KB.

3 Lessons

1. Don't over-engineer. React + Vite + Tailwind would've been 200KB before writing logic. Plain HTML/CSS/JS. Each tool loads < 50ms.

2. Privacy sells. The #1 feedback: "wait, nothing gets uploaded?" "Runs locally" is a stronger pitch than "10+ features."

3. Build what you search for. Every tool is something I've Googled myself. The best product ideas come from your own workflow.

Try Them

👉 https://matengtian.github.io/devtools/

Need custom scripts, bug fixes, or data analysis? DM me for rates.

Built with Claude Code. Published as part of my build-in-public journey.

I Built 8 Free Browser-Based Developer Tools (No Uploads, No Tracking)

matengtian — Wed, 27 May 2026 08:33:25 +0000

'## What I Built

Eight developer tools that run entirely in your browser — no files uploaded, no server-side processing, no tracking.

Tool	Description
JSON Formatter	Beautify, validate, compress JSON. CSV export
Image → Base64	Drag & drop, instant Data URI generation
SQL Formatter	Pretty-print with keyword highlighting
Markdown → HTML	Real-time GFM preview with code blocks
UUID Generator	Crypto-secure UUID v4 + ULID
Regex Tester	Real-time match highlighting
Timestamp Converter	Unix seconds/ms ↔ date
Diff Checker	Line-by-line comparison

Why

Every other online dev tool uploads your data. These run 100% client-side — nothing leaves your browser.

Tech

Pure HTML/CSS/JS. Zero frameworks. Under 30KB. Loads in 50ms.

Try

👉 https://matengtian.github.io/devtools/

Feedback welcome! What tool should I add next?