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

# worlds build

> Build World

Starts an asynchronous World build from ready Simulators and returns it in the pending state. Builds start in queue order when workspace capacity is available. Instructions generate and validate initial synthetic data. Start the World once it is ready to create its Simulations.

```bash theme={null}
continuous worlds build [flags]
```

## Examples

```bash theme={null}
continuous worlds build --simulators smr_01J8Z5X4K7M2N9P0Q1R2S3T4V5
```

## Flags

<ParamField path="--body" type="string">
  Request body as JSON (alternative to individual flags). Can also be provided via stdin.
</ParamField>

<ParamField path="--builder, -b" type="string">
  Legacy provider selection. Alone it selects the provider's default model (openai is gpt-6-astra, claude is claude-fable-5-1); with model it must name the model's provider. (options: openai, claude)
</ParamField>

<ParamField path="--instructions, -i" type="string">
  Describe the initial data, scenario, and relationships. Populated Worlds support up to 8 selected Simulators and 1,000 starting records in total. Named record types replace their default data. At most 16,384 characters and 65,536 UTF-8 bytes. U+0000 is not permitted.
</ParamField>

<ParamField path="--model, -m" type="string" default="gpt-6-astra">
  Model that builds and reviews starting data. Defaults to gpt-6-astra. Its provider is derived from the model. (options: gpt-6-astra, gpt-6-sol, claude-opus-5-5, claude-fable-5-1)
</ParamField>

<ParamField path="--name, -n" type="string">
  Name for the World. Omission generates a name. The ID stays its identity, and names need not be unique.
</ParamField>

<ParamField path="--simulators" type="stringArray" required>
  Simulator IDs for the World.
</ParamField>

<ParamField path="--start-time" type="string">
  Simulated time the World starts at, in RFC 3339 format. Omission uses 2024-01-01T00:00:00Z. Saved starting data keeps its build dates.
</ParamField>

<ParamField path="--timeout-seconds, -t" type="int" default="14400">
  Time limit for generation and validation in seconds, from 1 to 72000. Defaults to 14400 (four hours). Excludes queue wait and finalization. Retries share the same deadline.
</ParamField>

Global flags apply to every command. See [Global flags](/cli/global-flags).