Custom API Development
in Manchester
— AI-Ready from Day One

Most custom API development projects in the UK are built without AI in mind. They expose data endpoints, handle authentication, and stop there. When a client later wants to add AI features, they find the API wasn't designed for it — and a costly rebuild begins.

At Niobotics, based in Leigh, Manchester, we build every API AI-ready from the first line of code. This means the same API that serves your web app can also accept structured LLM outputs, handle streaming token responses, and feed data into RAG pipelines — without any modification.

What an AI-ready API actually means

Function-calling schema support

GPT-5 and Claude support function calling — the ability to call your API endpoints as tools, passing structured JSON parameters. We design our APIs with OpenAPI schemas that map directly to LLM function-call definitions. Your AI can search your database, create records, and trigger actions without any prompt engineering hacks.

Structured output validation

LLMs can hallucinate. We use Zod schemas to validate every request and response at the API layer, not just the frontend. If an LLM returns malformed data, the API rejects it cleanly and logs the failure — rather than silently corrupting your database.

Streaming response handlers

Modern LLMs stream tokens as they're generated. We build APIs with Server-Sent Events (SSE) support so your UI can display streaming AI responses in real time — the same pattern used by ChatGPT's interface.

RAG pipeline endpoints

Retrieval-Augmented Generation (RAG) lets your AI answer questions based on your own data. We build the full pipeline: pgvector embeddings stored in Supabase, semantic search endpoints, context assembly, and injection into the LLM prompt — all as versioned API routes.

Authentication and security

Every API we build includes:

• JWT bearer token authentication with refresh token rotation
• OAuth2 flows (authorization code with PKCE for public clients)
• Rate limiting per IP and per user token via Upstash Redis
• CORS policy enforcement with explicit origin allowlists
• Input sanitisation against SQL injection and XSS
• Full OpenAPI/Swagger documentation generated from code

What it costs

A full custom REST API with LLM integration, authentication, documentation, and deployment costs around £100 at Niobotics. Other UK API development agencies charge £3,000–£15,000 for comparable work. We keep costs low by using lean serverless infrastructure and AI-assisted development tooling.

Free ongoing maintenance and upgrades are included indefinitely.