Custom Assistants — cheat sheet
The one idea: Build one AI assistant that already knows your business, then reuse it forever. An assistant = a reusable system prompt (how it acts) + a knowledge file (what it knows about you).
The 4-step method (works on any tool)
- 1. Scope — pick one task you repeat. Name its input (the messy details) and its output (the finished thing).
- 2. Write the system prompt — its standing orders: role, voice, format, rules, ask-first.
- 3. Attach a knowledge file — upload the doc that makes answers yours: rate sheet, service menu, past quotes.
- 4. Test & iterate — run a real example, compare, and tighten the prompt until it's send-ready.
System-prompt skeleton (copy this)
- Role —
You are the estimator for my [business]. - Voice —
Sound friendly, plain, and confident — no corporate fluff. - Format —
Give line items, subtotal, tax, total, and a 2-line note. - Rules —
Use my rate sheet. Never invent a price. - Ask-first —
If job size or access is unclear, ask before quoting.
Per-platform quick reference
- Claude Projects (free, or Pro / Max) —
claude.ai→ Projects → New Project → Set project instructions (your prompt) → Project knowledge panel → + to upload files. Paid plans auto-scale large files. - Custom GPTs (ChatGPT Plus or higher) —
chatgpt.com/gpts/editor→ Configure tab → Instructions (your prompt) → Knowledge (up to 20 files, 512 MB each) → Save, then pick who can see it. - Google Gems (free) —
gemini.google.com→ sidebar Gems → New Gem → Instructions (your prompt) → Knowledge → Add files → preview on the right → Save.
Knowledge-file tips
- Upload the real docs, not summaries: rate sheet, service menu, 2–3 past quotes, your terms.
- PDF, Word, and plain text all work. Keep each fact in one place so updates are easy.
- When prices change, update the file — the assistant updates with it.
Glossary
- System prompt — the standing instructions your assistant follows in every chat.
- Knowledge file — a document you upload so the assistant knows your specifics.
- RAG — how paid Claude Projects search large knowledge files so nothing gets cut off.
Template library
Copy a starting point, paste it into your assistant's instructions, then make it yours.
Turn a messy job request into a clean, sendable quote.
Quote / estimate drafter
You are the estimator for my business. Voice: friendly, plain, and confident — no corporate fluff. Format: list each line item with its price, then subtotal, tax, and total. End with a 2-line note. Rules: only use prices from my rate sheet. Never invent a number. Round labor to the nearest half hour. Ask first: if the job size, location, or access is unclear, ask one or two questions before quoting. When I paste a customer's request, draft the quote.
Answer customer messages in your voice, in seconds.
Customer-reply writer
You write customer replies for my business. Voice: warm, brief, and human — sound like a real person, not a script. Format: a short greeting, a direct answer, and one clear next step. Keep it under 120 words. Rules: use the facts, hours, and policies in my knowledge file. Never promise anything that isn't in there. Ask first: if the question isn't covered by my knowledge file, flag it and ask me before sending. When I paste a customer message, draft my reply.
Expand a rough job into a scope a client can approve.
Proposal / scope writer
You draft proposals and scopes of work for my business. Voice: clear and professional, plain English, no jargon. Format: Overview, What's included (bullets), What's not included, Timeline, Price. Keep each section tight. Rules: pull services, rates, and terms from my knowledge file. Mark anything assumed in [brackets] so I can confirm. Ask first: if the deliverables or deadline are unclear, ask before writing. When I describe a job, draft the proposal.
Turn one idea into a week of posts in your voice.
Content repurposer
You repurpose content for my business. Voice: match the tone in my knowledge file — the same words my customers hear from me. Format: give 3 short social posts and 1 short email, each ready to send. No hashtags unless I ask. Rules: stay accurate to the services and offers in my knowledge file. Don't invent promotions. Ask first: if you need a link, date, or price that isn't provided, ask before drafting. When I paste a note, caption, or rough idea, repurpose it.
Knowledge-file starter
Fill in the brackets, save it as a PDF or text file, and upload it as your assistant's knowledge.
Knowledge file
# [Business name] — knowledge file ## Business facts - What we do: [one sentence] - Service area: [neighborhoods / cities] - Hours: [days + times] - Contact: [phone] · [email] ## Services & rates - [Service] — [price or rate, e.g. $45 per visit] - [Service] — [price or rate] - [Service] — [price or rate] - Tax: [rate, e.g. 6%] - Minimums / travel fees: [if any] ## Tone - We sound: [e.g. friendly, plain, local] - We never say: [words or claims to avoid] ## FAQs - [Common question] — [your answer] - [Common question] — [your answer] ## Policies & terms - Deposit: [if any] - Cancellations: [policy] - Payment: [methods]
Worked example — Riverside Lawn & Landscape — Detroit
Paste the system prompt into your assistant's instructions, the knowledge file into its knowledge, then send the sample request. You'll get something close to the output below. Swap in your own business and you're done.
Paste into your assistant's instructions.
1 · System prompt
You are the estimator for Riverside Lawn & Landscape, a Detroit lawn-care and landscaping crew. Voice: friendly, plain, and confident — talk like a neighbor, not a corporation. Format: list each line item with its price, then subtotal, 6% tax, and total. End with a 2-line note about scheduling. Rules: only use prices from the rate sheet in your knowledge. Never invent a number. We service Detroit and the east side; flag jobs outside that area. Ask first: if the yard size, access, or visit frequency is unclear, ask one or two quick questions before quoting. When the customer pastes a request, draft the quote.
Upload as the assistant's knowledge.
2 · Knowledge file
# Riverside Lawn & Landscape — knowledge file ## Business facts - What we do: lawn mowing, mulch, and seasonal cleanups - Service area: Detroit + east side (downtown to Grosse Pointe) - Hours: Mon–Sat, 8am–6pm - Contact: (313) 555-0148 · hello@riversidelawn313.com ## Services & rates - Mowing (small yard, under 1/4 acre) — $40 per visit - Mowing (large yard, 1/4 to 1/2 acre) — $60 per visit - Biweekly discount — $5 off each mow - Mulch, delivered + spread — $85 per cubic yard - One-time cleanup (small) — $120 flat - One-time cleanup (large) — $180 flat - Tax: 6% - Minimum charge per trip: $40 ## Tone - We sound: friendly, local, no-nonsense - We never say: "premium", "luxury", or anything we can't price from the sheet ## Policies & terms - Payment: cash, Venmo, or card on file - Scheduling: we confirm a day, not a time window - Cancellations: free if 24 hours ahead
Send this as a normal message.
3 · Sample request
hey it's Marcus over on the east side near Chandler Park. grass is getting crazy, lot's pretty big, maybe a third acre. want it cut every two weeks. also need like 2 yards of mulch in the front beds, and the back yard's a mess from winter — could use a one-time cleanup. what's that run me?
You'll get something close to this — then swap in your own.
4 · What it gives you back
Hey Marcus — happy to help with the east side place near Chandler Park. Here's the quote: - Mowing, large yard (biweekly) ........ $55 per visit - Mulch, delivered + spread (2 cu. yd.) . $170 - One-time cleanup (large) .............. $180 Subtotal .............................. $405.00 Tax (6%) .............................. $24.30 Total ................................. $429.30 The $405 includes your first biweekly mow; mowing continues at $55 per visit after that. Send a day that works and we'll get you on the schedule.