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

> ## Agent Instructions
> To build and serve your own model, start at /deploy/development/quickstart and /deploy/development/overview. Deploying is the default path: reactor init scaffolds a workspace, reactor auth login authenticates, and reactor model deploy registers the model, publishes the release with the weights/ folder, and activates it on Reactor's GPUs, in one command from that workspace. Docker must be running, because the publish step builds the image locally. Bump model.version in reactor.yaml before redeploying a change, because a release that already has an image is reactivated as it is. Deployment access is granted per account, so contact team@reactor.inc if a deploy is refused. Every key in reactor.yaml is documented at /deploy/platform/reactor-yaml. Model code imports reactor_runtime; Python client code imports reactor_sdk. The runtime overview explains the model interface. Running the model on your own machine with reactor run is optional and needs a GPU you attach with --gpus; /deploy/development/local-testing covers that loop and pairs a complete brightness model with a Python client test in a separate brightness-test workspace.
> Reactor hosts multiple models, each with its own connect slug (modelName) and command/event schema. The video model catalog — slug, typed SDK package, and links to its schema — is at /model-api-reference/overview. Robotics policy documentation starts at /robotics/overview; X-WAM observations, actions, and client integration are under /robotics/xwam/; Cosmos3 Nano Policy DROID is under /robotics/cosmos/nano-policy-droid/. Some models expose one slug per experience (e.g. HappyOyster); always take the slug from the model's own pages, never guess it.
> Fastest path to a working app: `npx create-reactor-app my-app --model=<slug>` scaffolds a complete app with secure auth wired up. Typed TypeScript SDKs are published as @reactor-models/<model>; Python uses the base reactor-sdk package.
> Auth: exchange an API key (rk_...) for a JWT via POST https://api.reactor.inc/tokens from your server. Never put the API key in client-side code.
> Append .md to any docs URL for clean Markdown. Search these docs via the MCP server at https://docs.reactor.inc/mcp.

# Cosmos3 Nano Policy

> Joint-position actions from the DROID variant of NVIDIA Cosmos3 Nano Policy.

Cosmos3-Nano-Policy-DROID predicts an action chunk from a wrist camera, two exterior cameras,
measured joint and gripper state, and a language instruction. Reactor hosts inference; your
application executes the returned targets.

## Variant and compatibility

| Property | Value |
| - | - |
| Model identifier | `reactor/cosmos-nano-policy-droid` |
| Family | NVIDIA Cosmos3 Nano Policy |
| Checkpoint | [Cosmos3-Nano-Policy-DROID](https://huggingface.co/nvidia/Cosmos3-Nano-Policy-DROID) |
| Reference embodiment | DROID: seven-joint Franka arm and gripper; RoboLab uses a Robotiq 2F-85 gripper |
| Action representation | Seven absolute joint positions in radians, plus normalized gripper closure |
| Prediction horizon | 32 control steps; 8 values per step |
| Request mode | First chunk from observations; subsequent chunks require an executed-step acknowledgement |
| Documented model release | `0.4.2`; see [release notes](/robotics/cosmos/nano-policy-droid/changelog) |

The identifier selects the DROID variant. Other Cosmos checkpoints and robot embodiments do not
inherit this observation/action contract. A seven-joint robot is not automatically compatible: joint
ordering, gripper convention, camera geometry, and training distribution must match.

| Path | What is provided |
| - | - |
| First actions | A Python example using synthetic camera fixtures; no simulator or local model weights |
| Simulation | An OpenPI-compatible gateway for NVIDIA RoboLab's Cosmos3 client |
| Physical robot | Contract and integration guidance; these examples do not supply a validated hardware driver |

## Use the model

Start with [Get your first actions](/robotics/cosmos/nano-policy-droid/quickstart), then choose
[simulation](/robotics/cosmos/nano-policy-droid/simulation) or
[robot integration](/robotics/cosmos/nano-policy-droid/integration). The
[reference](/robotics/cosmos/nano-policy-droid/reference) specifies the wire contract.

Reference clients live in the public
[simulator examples in Reactor’s public cookbook](https://github.com/reactor-team/reactor-cookbook/tree/main/robotics/sim).
Contact [Reactor](mailto:team@reactor.inc) if you need hosted model access.


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