LLM integration · how to
How to Integrate an LLM Into Existing Business Software (CRM, POS, Messengers)
Integrate an LLM into existing business software by putting the model at the edge of a flow you already trust, not in the middle of it. Read from the CRM or POS through its API, let the model draft, classify or summarise, keep exact calculations and permissions in ordinary code, and test the whole path on real data before anyone depends on it.
01The shape of a safe integration
The system you already run stays the source of truth. The model never writes straight into it without a check, and anything that must be exact goes through code, not through a prompt.
02Where an LLM helps, and where it should not decide
Good fit for a model
- Drafting messages and replies
- Classifying free text and requests
- Summarising long histories
- Extracting fields from documents
Keep in ordinary code
- Money, totals and prices
- Permissions and who may do what
- Dates, schedules and booking rules
- Anything an auditor must reproduce
03Step by step
- Map the flow. Who does what today, and what data moves where.
- Read through the API. Use the system's own interface with the narrowest permissions that work.
- Separate the exact from the fuzzy. Rules first, model second.
- Give the model a small job. One task per call, with the context it needs and nothing more.
- Verify the output. Check formats, ranges and business rules before anything is written back.
- Test on real data and keep the tests; they are what lets you change the prompt or the model later.
04An example from my work
The CRM I built for a network of clubs sits on top of the booking and payment software the clubs already used. It adds WhatsApp mailings with its own click tracking, funnels, reports and trainer pay, and it does not replace the existing systems. Data and permissions are scoped per club. The principle is the same for an LLM feature: build around what works, scope access, test the path.
FAQShort answers
- Do I need to replace my CRM to use an LLM?
- No. A well-scoped integration reads from and writes to your existing CRM through its API.
- Is it safe to send customer data to a model?
- It depends on the data and the provider. Send only what the task needs, and agree with the owner which fields may leave your systems.
- How do I test an LLM feature?
- Build a set of real examples with known correct outcomes, run the whole flow on them, and re-run after every change to the prompt or model.
- How long does a first integration take?
- A narrow flow can be done in a few days to a couple of weeks, depending on how accessible the system's API is.
Have a task like this? Write to me.