What is an agent runtime?
An agent runtime is the environment where agents actually live: it executes their tool calls, manages memory and context, enforces permissions, and records what happened. Models think; runtimes act.
Why a model alone is not enough
An LLM emits text — including text that says "call this tool". Something must execute that call, handle the failure, retry, log it and feed the result back. That something is the runtime, and its quality decides whether agents are reliable.
What good runtimes provide
Tool execution with permissions, persistent memory, context management, scheduling and triggers, human approval gates, and receipts. The checklist is mundane; shipping it well is the product.
Local-first as a runtime choice
Where the runtime lives determines who owns your keys, data and history. A local-first runtime keeps them on your machines and makes the cloud optional — the reverse of the usual arrangement.
Build or buy
Writing your own runtime is appealing and usually a mistake, because the difficulty is not in the first version. It is in the second year: permission models, retry semantics that do not duplicate side effects, context assembly, credential rotation, and the audit trail somebody will eventually demand. Teams that start by writing a framework wrapper generally rebuild this list badly while their competitors are shipping workflows on one that already exists.
Common questions
Is AGNT a framework or a runtime?
A runtime — a running product with visual workflows and a marketplace — rather than a code library you assemble into one.
Can one runtime use many model providers?
Yes; AGNT normalises tool calling across frontier APIs and local models, so workflows are provider-portable.
What should I look for when comparing runtimes?
Tool execution with real permissions, persistent memory, approval gates, triggers, provider portability and receipts. If any of those is missing you will end up building it.