If you've used ChatGPT or Claude for any length of time, you'll have noticed something. The first time you ask a question, the answer is usable but generic. By the fifth or sixth turn, after you've explained your business, your customers, and what you actually need, the answer is much sharper.
That isn't a coincidence. The AI got better because you gave it context.
A context file is a way to deliver all of that information at the start of the conversation, instead of typing it in piecemeal every time. You write it once, paste it in once, and every answer that follows is shaped by it.
What exactly is context?
Context is everything the AI knows about your situation before you ask the question.
When you talk to a colleague who has been at your company for ten years, you don't need to explain who your biggest customer is, or why the warehouse process changed last March. They already know. The conversation starts further down the road.
When you talk to a general AI for the first time, it's like talking to a clever stranger. They can reason well, but they have no shared starting point with you. Every answer is based on what an average business looks like, not what your business looks like.
Context is the shared starting point. The more accurate and current that starting point is, the better the answers are.
What are the four types of context?
Most useful context files fall into four categories. You don't need every category for every conversation, but if you cover all four, the AI behaves much closer to how a competent colleague would.
Identity context. Who the business is. What it makes or sells. Who it sells to. Where it operates. The history that still shapes how decisions get made. This is the foundation. Without identity context, the AI defaults to writing for "businesses" in the abstract.
Operational context. How the business actually works day to day. Your pricing model. Your customer segments. Your suppliers, your lead times, your products, your processes. The parts that look ordinary from the inside but are distinctive once you compare them with the business next door. This is the layer that converts generic advice into specific advice.
Voice context. How the business sounds when it speaks. The words you use. The words you don't. The tone your customers expect from you. Whether you write formally or informally. Whether you're cautious or direct. Without voice context, an AI will draft in a register that sounds nothing like you, and your customers will notice immediately.
Rules context. What the business won't do. Topics you won't comment on. Claims you won't make. Customers you won't take on. Tone you won't allow. This is the part most people forget, and it's the part that protects you from the AI writing something embarrassing on your behalf.
What is an example of a context?
Let's make this concrete.
Imagine a wholesale distribution business in the Midlands. Identity context tells the AI it sells industrial fasteners to manufacturers, mostly in the automotive and aerospace sectors, and that it's been trading for thirty years from the same family ownership.
Operational context tells the AI that customers are tiered by annual spend, that any order under £50 attracts a small-order surcharge, that lead times for standard SKUs are 48 hours and for special-order items between two and six weeks, and that the company stopped using one of its major suppliers last spring because of quality issues.
Voice context tells the AI to write the way the sales team writes. Plainly and confidently. Never marketing speak. Never opening an email with "I hope this finds you well". Always signing off with the regional account manager's name.
Rules context tells the AI not to quote prices in writing, not to promise delivery dates without checking, not to comment on competitors, and not to engage with anything that looks like a complaint or a chargeback without escalating.
With all four loaded, the AI stops sounding like a stranger and starts sounding like a member of the team. Not perfect, but close enough to be genuinely useful. A draft a person can edit, not a draft a person has to rewrite from scratch.
Where to start
You don't have to write all four sections in one go. Most people start with identity and operational context, since those answer the most common questions. Voice and rules tend to grow over time, as you spot patterns in the answers you keep correcting.
The point is to write it down once, in a place you can paste from, rather than re-explaining your business in every new conversation.
That's all a context file really is. A short document, written in plain English, that means the AI never has to meet you for the first time again.