> ## Documentation Index
> Fetch the complete documentation index at: https://docs.firedrill.run/llms.txt
> Use this file to discover all available pages before exploring further.

# Worlds and state

> Understand the isolated environment in which an agent acts.

A **world** is the isolated, stateful environment in which Tools, actors, time, events, and faults interact.

## Shared consequences

All Tools selected for one attempt share that attempt's SQLite-backed world. This lets a call to one Tool schedule an event, change data observed by another Tool, or affect a later assertion while preserving one causal order.

The SQLite file is runtime state—not a representation of the agent's own production database. Repository files define the reproducible baseline. Tool calls mutate only the isolated runtime copy.

## What the world contains

* Tool-owned state namespaces and records
* actors and operation grants
* virtual clock and deterministic randomness
* pending events and scheduled work
* active faults and response overrides
* callbacks and subscriptions
* an append-only causal journal

Every trial and retry receives its own world. Concurrent drills do not share mutations.

## Baseline, scenario, and runtime state

| Layer          | Purpose                                                 | Changes source files?             |
| -------------- | ------------------------------------------------------- | --------------------------------- |
| World baseline | Default Tools, records, actors, permissions, and time   | Yes, when you edit the repository |
| Scenario       | Reusable variation for a starting condition             | Yes, when you edit the scenario   |
| Per-test setup | Temporary data, faults, bindings, or behavior overrides | No                                |
| Runtime state  | Consequences produced by one attempt                    | No                                |

## Read and control state

The CLI and inspector expose the world through bounded, paginated views. The local TypeScript SDK can call operations, read state and evidence, advance virtual time, export a scenario, and perform full or Tool-scoped resets.

<Card title="Control state and time" icon="clock" href="/guides/control-state-time">
  Seed records, activate faults, advance the clock, and reset the world.
</Card>