Documentation Reference Glossary

Glossary

1 min read·Updated 30 Jul 2026

Terms as this documentation uses them. Where a word has a loose industry meaning and a precise Arble meaning, the precise one is given.

AgentA reusable configuration: a model, a set of tools, and instructions. Not a running process — that is a run.
RunOne execution of an agent. Has a status, a deadline, and usage.
SessionA conversation with accumulated context. Runs happen inside sessions.
ToolOne typed capability the agent can call, with an input and output schema.
SkillA packaged procedure that calls tools. A way of working, not a capability.
ConnectorAn authenticated link to an external service, contributing tools.
MCPModel Context Protocol. A standard for exposing tools to any compatible client.
Tool registryThe single index of every callable tool, regardless of source.
PlannerThe component that picks which tool to call for a step.
Permission gateThe check every tool call passes before executing.
CapabilityA permission subject, such as filesystem.write.
ScopeThe narrowing on a capability — a path, a host, a repository.
MemoryDurable per-project facts, retrieved semantically. Outlives sessions.
ProjectThe unit that scopes memory, permissions and connectors.
WorkspaceSeveral projects sharing memory and connectors.
ProfileAn endpoint, organization and credential under one name.
WorkerThe sandboxed process that executes tool code. Holds no database credentials.
ResourceA typed non-scalar tool input or output — a file, image, table or database handle.
Requires actionA run paused waiting on you, for an approval or a tool result.
DrainLetting in-flight runs finish before a process shuts down.