Your mobile app needs a back-end. Your website has to talk to your database. Your internal tools don't communicate with each other. In all three cases, the missing piece is the same: an API.

A well-built API (or REST API / RESTful API) is what lets your website, your mobile app and your internal tools exchange data without depending on each other. I build custom APIs in **Node.js (Nodejs) / Express** or **FastAPI (Fast API) / Python**, depending on your stack or your preference. You don't need to pick the technology before contacting me, we can decide together.

I'm not starting from scratch here. Two projects I built are running in production today: **thelawgpt.com**, an AI legal platform, and **allinone.tools**, a platform of 70+ online tools with more than 50,000 active users that has processed 1 million files. Behind them are dozens of real endpoints: full authentication, payment webhooks (Stripe / Dodo Payments), AI call orchestration, document processing, admin back-office. This isn't basic CRUD, it's code running in production with real users.

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## "How many endpoints do I need?"

Everyone asks this, so here's a concrete guide. One endpoint = one action your application can ask the API to perform.

- **A contact form + a list of articles** → 2 to 3 endpoints
- **A full product catalogue** (list, view details, create, update, delete) → around 5 endpoints
- **The same catalogue + user accounts + cart** → around 10 endpoints
- **A complete application with payments, notifications and admin panel** → 15 endpoints and up

Not sure where you fit? Just describe what your application needs to do and I'll count them for you before you order.

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## BASIC €50 - Simple, working API

- Up to 5 endpoints (GET / POST / PUT / DELETE)
- Database connection (PostgreSQL, MongoDB, MariaDB or ClickHouse)
- File handling (upload / download) if your project needs it
- Input validation + error handling
- Source code delivered as a .zip
- 2 revisions
- Delivered in 5 days

**Best for**: a one-off need, a prototype, or a small project without authentication.

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## STANDARD $127.42 - Secure, documented API

**Includes (everything in Basic, plus):**
- Up to 10 endpoints
- Secure authentication (JWT or OAuth, depending on your needs)
- Interactive Swagger / OpenAPI documentation (generated automatically with FastAPI, or via swagger-jsdoc in Node.js)
- Security best practices: rate limiting, CORS configuration, input sanitisation
- 4 revisions
- Priority delivery, in 8 days

**Best for**: an API meant to be used by real users, not just internally.

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## PREMIUM $208.50 - Production-ready API

**Includes (everything in Standard, plus):**
- Up to 15 endpoints (beyond that: custom quote)
- Webhooks and third-party integrations (payments, email, AI...)
- Automated tests on critical endpoints
- Setup and deployment on VPS or cloud (Docker containerisation if needed)
- Unlimited revisions
- 7 days of post-delivery support
- Delivered in 11 days

→ Real example: the back-end of thelawgpt.com, with authentication, payment webhooks, AI call orchestration, document generation and analysis.
→ Real example: the infrastructure behind allinone.tools, with 70+ tools, 50,000 active users and 1 million files processed.

**Best for**: a project that will genuinely run in production, where reliability and security matter.

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## Technologies I work with

**JavaScript / TypeScript back-end**
Node.js (Nodejs), Express (Express.js), NestJS on request, JavaScript (JS), TypeScript (TS)

**Python back-end**
FastAPI (Fast API), Flask, Pydantic, Uvicorn, native OpenAPI documentation

**Databases**
PostgreSQL (Postgres), MySQL / MariaDB, MongoDB (Mongo), ClickHouse, Supabase, SQLite, and the Prisma, Mongoose and SQLAlchemy ORMs

**Security and authentication**
JWT (JSON Web Token), OAuth 2.0, bcrypt, rate limiting, CORS, input validation, GDPR

**Documentation and testing**
Swagger / OpenAPI, Postman, Insomnia, Jest, Pytest

**Third-party integrations**
Stripe (payments and webhooks), Dodo Payments, PayPal, OpenAI (GPT), Anthropic (Claude), email services (Resend, SendGrid, Nodemailer), Twilio, custom webhooks

**Deployment and infrastructure**
Docker, VPS (Ubuntu, Debian), Nginx, Vercel, Railway, Render, GitHub Actions (CI/CD), environment variables and secrets

**Formats and protocols**
REST (REST API / RESTful), JSON, CRUD, GET / POST / PUT / PATCH / DELETE, pagination, filtering and sorting, file upload, GraphQL on request

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## What I need from you

- A description of what the API should do (a few sentences is enough, no formal spec needed)
- Your data structure if you already have one (tables, fields, sample content)
- Any third-party services to integrate (Stripe, email provider, AI API...)
- Your server / cloud access, only if you order the Premium package with deployment

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## What is NOT included by default

- The front-end / interface that consumes the API (see my web development service if you need that too)
- Domain name and hosting (I can guide you through the setup)
- Maintenance beyond the support period included in the Premium package

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## Proof of delivery

Before closing your order, I send you proof of the work in the chat: a screenshot, a live API call, a link to the Swagger documentation, and so on.

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## Client feedback

*Reviews across all my services (web development, APIs, SEO), translated from French:*

- "Professional and skilled" — zoomcommerce
- "Excellent, fast and efficient, highly recommended!" — BilelAYACHI
- "Very satisfied, relevant and efficient work, delivered on time, I recommend" — Randy03
- "Very professional work, fast and attentive, my site went from 46 to 81, I recommend!" — YasmineEl302

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## Frequently asked questions

**Node.js or FastAPI, how do I choose?**
If you already have a JavaScript/TypeScript project (a Next.js front-end, for example), Node.js integrates more naturally. If your project involves data, computation or AI, FastAPI (Python) is often the better fit. Not sure? Just tell me what the API needs to do and I'll advise you.

**Do I own the source code?**
Yes, without exception, delivered as a .zip, with no dependency on a subscription or third-party licence.

**Can I contact you before ordering?**
Yes, and I recommend it if your project goes beyond 15 endpoints or needs a specific integration. I'll quote it properly rather than forcing your project into a standard package.

**Can you connect the API to my existing database?**
Yes. Send me the current structure (or read access) and I'll build the API on top of it, without rebuilding your data from scratch.

**Can I add endpoints later?**
Yes. The code is structured and documented for exactly that. You can continue on your own, or come back to me for the next iteration.

**How do I test the API if I'm not a developer?**
With the Standard and Premium packages you get interactive Swagger / OpenAPI documentation: a web page where you click each function and test it live, without writing a single line of code.

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## Need a website or app that consumes this API?

I also offer custom web development (React / Next.js, web apps and SaaS): https://comeup.com/fr/sales/service/85549b01-04f0-499c-927d-3d56da61a5b3/title

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Got a question before ordering? Describe your project in a few lines and I'll tell you quickly which package fits, and how many endpoints you actually need.