A browser agent can need permission to log in without needing to read the user's password. Browserbase, which supplies browser infrastructure for agents, describes how a agent harnessThe scaffolding around a model that turns it into a working agent — the loop, the tools it can call, and the rules for when to stop.Full definition → can separate those responsibilities. The model requests a login action using a session reference and temporary access credentials; software surrounding the model holds the actual secret and fills the password field outside the model's context windowThe maximum amount of text a model can consider at once — its working memory for the current conversation or task.Full definition →. This credential-brokering design places sensitive operations in a controlled execution layer while leaving the model responsible for deciding the next step.
Terms in this piece · Glossary
agent harness — The scaffolding around a model that turns it into a working agent — the loop, the tools it can call, and the rules for when to stop.
context window — The maximum amount of text a model can consider at once — its working memory for the current conversation or task.
context compaction — Summarizing an agent's earlier conversation to free room in the context window so a long session can keep going.
agent skill — A reusable instruction file that teaches an agent how to do one job well — the procedure, the tools, and what counts as done.
