> ## Documentation Index
> Fetch the complete documentation index at: https://levers9.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Concepts

> The words you will meet, in the order you will meet them

## Things you run

| word | meaning |
| - | - |
| **Job** | a Python function that runs in a container: `.remote()` once, `.map()` fan-out, `.remote()` from another function to build pipelines |
| **Endpoint** | a function behind an HTTP URL, invoked synchronously; `@asgi` wraps a whole ASGI app, `@realtime` a WebSocket handler |
| **Queue** | background work, one task per item, with retries; `.put()` from Python or `POST` from anywhere |
| **Cron** | a function on a cron expression (UTC) |
| **Box** | any long-running process with ports, for servers, databases and notebooks |
| **Sandbox** | a box you drive from Python: run code and processes, read and write files, expose ports, snapshot memory |
| **Task** | one execution of any of the above; it has a status (pending, running, complete, error), a container and logs |
| **Container** | the process running a task. A container that is already up answers immediately; one that has to start pays for the blueprint, the container setup and whatever the process loads - see [Cold starts](https://levers9.mintlify.site/sdk/cold-starts.md) |

## Things you attach

| word | meaning |
| - | - |
| **Blueprint** | what is installed in the container: Python version, pip and apt packages, shell commands. Built once and content-addressed, so a changed line rebuilds only from that step |
| **Volume** | persistent files shared between containers, browsed in the dashboard or with `levers9 ls / cp / rm`; a `CloudBucket` mounts S3 or GCS the same way |
| **Secret** | a value stored in the workspace and injected as an environment variable into containers that ask for it |
| **GPU** | `gpu="L40S"` or a preference list; the scheduler takes the first type with free capacity. `gpu_count=2/4/8` gives one job several cards on one node for one training with `levers9.distributed`; `.map()` over `gpu_count=1` jobs runs many trainings side by side. See [Train on 1, 2, 4 or 8 cards](https://levers9.mintlify.site/guides/multi-gpu.md) |
| **Pool** | a group of workers with the same hardware (`default`, `build`, `l40s`); a box or job can be pinned to one |
| **Cluster** | a Kubernetes cluster you run, attached as a pool with `levers9 cluster join`: one agent inside it dials out, reports the GPU nodes, and starts workers when asked; nothing dials in. See [Attach a cluster](https://levers9.mintlify.site/guides/clusters.md) |

## Things you ship

| word | meaning |
| - | - |
| **Deployment** | a named, versioned thing you can call: `/job/NAME/v1`, `/endpoint/NAME/v2`, `/queue/NAME/v1`, `/box/NAME/PORT/...` (the older `/function`, `/taskqueue` and `/pod` paths still answer) |
| **Version** | every `levers9 deploy` makes one; older versions keep working until stopped |
| **App** | the group of functions and deployments in one script, shown together in the dashboard; deployed, stopped or ephemeral (ran once, never deployed) |
| **Serve** | a temporary URL for the code in front of you, with hot reload, gone when you stop it |

## Who you are

| word | meaning |
| - | - |
| **Workspace** | a team: its apps, volumes, secrets and members. Everyone with the same email domain shares one; you can create more for a project or a client |
| **Environment** | a separate space inside a workspace (`main`, `staging`, a branch). Each is a controlplane workspace of its own, so nothing leaks between them |
| **Token** | what the CLI and the dashboard use to act as one environment; `levers9 login` fetches it, `levers9 token` manages extra ones |
| **Context** | one entry in `~/.levers9/config`: controlplane host, port and token; switch with `-c NAME` |

Every abstraction takes the same knobs: `cpu`, `memory`, `gpu`, `image`, `volumes`, `secrets`, `env`,
`timeout`, `retries`. They are listed on [Parameters](https://levers9.mintlify.site/sdk/parameters.md).


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