Headless Agent
An agent in a chat window has a safety net it rarely gets credit for: a person reading along, ready to answer a question or pull the plug. A headless agent runs without that. No session, nobody watching — it is started by a schedule, a webhook or a queue message, works through the task, and writes its result somewhere durable.
What changes with nobody there
- It cannot ask. Every input has to arrive up front, and genuine ambiguity must resolve to a stop plus an escalation record, not a guess.
- Its budget is the only brake. Step limits, token caps and wall-clock timeouts, because nobody will notice a loop at minute forty.
- Output replaces the transcript. A pull request, a ticket, a row in a table — something a human finds later, without the reasoning that produced it in front of them.
- Runs must be idempotent, since a retried webhook will start the same work twice.
Why run one at all
Headless operation is how agent work scales past one person's attention: a coding agent triaging the overnight bug queue and opening a draft pull request, a nightly job reconciling records. It is also where tracing stops being optional — with no conversation to scroll back through, a tool like LangSmith holding the full trajectory is the only account of what happened. Pair it with durable execution and checkpointing so a crash at step thirty resumes rather than restarts, and with an approval queue for irreversible steps, asynchronous by necessity: there is nobody to ask in the moment.
A headless agent runs with no interactive session and no human present — triggered by a schedule, webhook or queue message, taking all its input up front and writing results to a durable sink such as a pull request, ticket or log. It cannot ask a clarifying question, so ambiguity must end in a stop, and step, token and time budgets plus tracing replace the supervision a chat session provides.
Think of a dishwasher rather than a sous-chef. With a sous-chef you are in the kitchen, answering questions as they come. With a dishwasher you load it, press start, and walk away. A headless agent is the dishwasher version of AI.
It runs with nobody watching — kicked off by a timetable or by something happening in another system — and it has to manage alone. That means everything it needs must be supplied before it starts, since there is no one to ask. It needs firm limits on how long it can run and how much it can spend. And it has to leave a clear record of what it did, because that record is all anyone will have afterwards.