Glossary
Every term teaspill uses, in one place. Terms are listed alphabetically; if you're new, read the Concepts section in order instead — it introduces each of these when you need it.
Agent
An AI agent that keeps working — and keeps its memory — across process restarts, deploys, and crashes. Every teaspill agent is a durable entity with its own timeline. → Defined in the Introduction.
API key
The server-side credential (tsp_…) for the gateway. It authorizes everything — spawn, send, control, registration — and belongs in backends, never browsers. → Defined in Auth & API keys.
Archive
An idle agent archives: its state is stored in the catalog and it stops costing anything. Its timeline stays readable. See also Resurrection. → Defined in Lifecycle & control.
Catalog
The Postgres registry of every entity — type, status, parent, tags — that your UI subscribes to as live-updating queries (via Electric). Lists and dashboards come from the catalog; conversation detail comes from timelines. → Defined in Projections & the catalog.
child_finished
The message a finishing child delivers to its parent, carrying the child's outcome and result. It arrives as a wake — never as a return value. → Defined in Durable agents.
Control verb
The four outside interventions: interrupt, pause, resume, archive. Everything else you want to tell an agent is just a message. → Defined in Lifecycle & control.
Drift
A reader-detected inconsistency in a timeline — a forward gap in seq where events should be. The client SDK surfaces it loudly instead of rendering a silently incomplete history. → Defined in Frontend integration.
Durable execution
A way of running code as a journal of recorded steps: if the process dies, the run resumes from the last completed step instead of starting over. teaspill gets this from Restate. → Defined in Durable agents.
Durable streams
The history store: the durable streams server holds every timeline, delta stream, and workspace output stream as append-only, resumable HTTP streams. → Described in Self-hosting.
Electric
The open-source Postgres sync engine that streams catalog rows to clients as live-updating subscriptions. → Introduced in Projections & the catalog.
Entity
Each running agent is an entity with a stable URL-shaped id (/t/default/a/researcher/01j…) used everywhere: in the catalog, in events, in the API. → Defined in Entities & addressing.
Executor
The service plane that hosts workspaces; it scales independently of the agents themselves. → Defined in Workspaces & execution.
Fast-join
Joining a long timeline at its latest snapshot and folding forward, instead of replaying from event 0. → Defined in Timelines & events, shown in Frontend integration.
Gateway
The single front door. Your app, your UI, and the CLI talk to teaspill only through the gateway. → Defined in the Introduction.
Harness
The engine that runs the model loop inside a wake. You pick one per agent: the native harness (teaspill owns the loop, any provider) or the Claude Agent SDK harness (Claude Code semantics). Swapping harnesses changes nothing else about the agent. → Defined in Harnesses.
History hole
A marked gap: after catastrophic history loss and recovery, the timeline says "history is missing here" instead of pretending otherwise. → Explained in Backup & restore.
Opaque event
A lossless carrier for records with no other canonical home — typically harness-internal data that must round-trip exactly. Most consumers ignore it. → Specified in the Event schema reference.
Outbox
The mechanism that makes projections exactly-once. You'll only care about the name if you work on teaspill itself. → Named in Projections & the catalog.
Projection
The one-way flow that copies what agents do out to the places you read from (the timeline stream, the catalog). Nothing is ever read back from a projection to make a decision. → Defined in Projections & the catalog.
Read token
An optional, short-lived token that lets a browser read streams and catalog shapes directly. A read token can never spawn, send, or control. → Defined in Auth & API keys.
Restate
The open-source durable-execution engine teaspill builds on. It runs as one of the stack's services; you never talk to it directly. → Defined in Restate in five minutes.
Resurrection
Sending to an archived agent resurrects it — same identity, same timeline, and the seq counter continues where it left off. → Defined in Lifecycle & control.
Revision
The version number of an agent type's state schema. Within a revision, changes must be additive; a breaking change bumps the revision, and existing instances keep theirs until they archive. → Explained in Building agents.
seq
An event's position on its entity's timeline: 0-based, gapless, counting up by one. seq — not the timestamp — is the ordering authority. → Defined in Timelines & events.
Snapshot
A periodic event that carries the entity's complete state at that point, so a UI can join a long timeline at the latest snapshot and fold forward, instead of replaying from event 0. → Defined in Timelines & events.
Spawn
Creating a new agent entity — from your backend, the CLI, or another agent. Spawn returns the new entity's id immediately; a child's result arrives later as child_finished. → Defined in Durable agents.
Steer
Injecting a message into an agent's current run mid-turn instead of queueing a new wake; degrades to a normal message if the agent isn't mid-turn. → Defined in Lifecycle & control.
Summarization
An event marking a context fold: for the model, older conversation is superseded by a summary once the context budget is crossed. History stays intact for UIs — nothing is deleted. → Specified in the Event schema reference.
Tenant
The namespace segment in every identifier (/t/default/…). One deployment is one tenant; the segment is a constant you rarely think about. → Defined in Entities & addressing.
Timeline
The append-only record of everything an entity does — messages, tool calls, results, lifecycle markers — as numbered events. The timeline is history you can read and replay; the platform never reads it to decide what to do next. Its records are called canonical events. → Defined in Timelines & events.
Token delta
The live, streaming fragments of a message while the model is still producing it. Deltas ride a sibling stream, are droppable, and are always superseded by the finalized event on the timeline. → Defined in Timelines & events.
Virtual object
A named, addressable unit with its own state that handles one invocation at a time. Every teaspill agent is one; "single-writer" means nothing else can mutate its state concurrently, which is what makes its event ordering trustworthy. → Defined in Restate in five minutes.
Wake
One turn of an agent's life. A message or a child finishing wakes the agent; it does some work (maybe calls the model, maybe spawns children), then goes back to sleep. Agents never block or poll — anything they're waiting for arrives as a later wake. → Defined in Durable agents.
Workspace
The sandboxed environment (filesystem + shell) an agent's tools run in, chosen when the agent is spawned. → Defined in Workspaces & execution.