> ## 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; The launch policies are Cosmos Nano DROID (/robotics/cosmos/nano-policy-droid/), DreamZero DROID (/robotics/dreamzero/droid/), and FLUX Action DROID (/robotics/flux-action/droid/), organized by model family and embodiment. 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=` scaffolds a complete app with secure auth wired up. Typed TypeScript SDKs are published as @reactor-models/; 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. # Get where a session runs > Returns a smaller view of the session that names where it runs: its state, its placement, and the instance that serves it. `machine_id` is empty until an instance picks up the session, and `cluster_id` is `""` until the session is placed. Only the user who started the session may call this. A session token reads only the sessions bound to it. ## OpenAPI ````yaml /openapi.yaml get /sessions/{session_id}/runtime openapi: 3.1.0 info: title: Reactor Platform API version: '1' description: > The Reactor Platform API mints session tokens, starts and operates sessions, negotiates media transport, and manages your account, models, and deployments. Every path is relative to `https://api.reactor.inc`. See the [Introduction](/platform-api/introduction) and [Authentication](/platform-api/authentication) pages for credentials, versioning, and errors. contact: name: Reactor support url: https://docs.reactor.inc/resources/support servers: - url: https://api.reactor.inc description: Production security: - apiKey: [] tags: - name: Status description: >- Public, unauthenticated endpoints for service health, pricing, and the values the API accepts. - name: Tokens description: > Exchange a long-lived API key for a short-lived, session-scoped token that a client can use to create and operate sessions without holding the key. - name: Users description: > Read your own user record, your account's roster, and account memberships, and manage member roles as an account admin. - name: API Keys description: >- Revoke API keys. Use the [Dashboard](https://reactor.inc/dashboard) to list or create keys. The CLI can also create a key with `reactor auth login`. - name: Sessions description: > Create, inspect, and end sessions. A session holds one running model for one client application; media and messages flow over a transport you attach to it afterwards. - name: Transport description: > Attach a client to a session. WebRTC signaling carries ICE servers, SDP, and ICE candidates; a LiveKit room connection lets the session join a room you host. - name: Files description: > Upload files a model reads, either for one running session or ahead of time for sessions you have not started yet. - name: Recordings description: > Fetch the recorded video of a session as an HLS playlist, during the session or after it ends. - name: Accounts description: > Read and manage the account your credential acts in: its name and slug, its credit balance, its effective quotas, and its accelerator capacity. - name: Invitations description: > Invite people to your account by email, and manage pending invitations. The recipient accepts from the emailed link while signed in to the dashboard. - name: Usage description: > List the sessions your account has run, filter them by status, date, model, or API key, and read exact session totals for a date window. - name: Models description: > Register, read, update, and delete the models your account serves, and list the models you can use. The `reactor model` CLI commands are built on these endpoints. - name: Releases description: > Register a model's versioned releases, push their container image, and deploy a release with a per-region instance plan. - name: Model Weights description: > Upload and inspect the weights bundle of a release: single-request uploads, multipart uploads for large files, and the server-side finalize that marks a bundle complete. - name: Model Schemas description: > Attach an OpenAPI schema to a release that describes the model's commands, messages, and tracks. Schemas of public models are readable without credentials. - name: Model Access description: | Share a private model with other accounts, one environment at a time. - name: Projects description: > A project is the deploy identity of a model you serve on Reactor. Each model is one project, with its own UUID. Creating a project also creates its `production` environment. - name: Environments description: > An environment is a named deploy target of a project, such as `production` or `staging`. Each write to an environment creates its next revision, and the newest revision is what the environment runs. Environment access grants let another account start sessions on one environment. - name: Revisions description: > A revision is an immutable, numbered snapshot of one environment: its model image, weights, resources, instances, and variables. An environment's revisions, newest first, are its change log. - name: Images description: > Model images are the container images pushed to your model's repository, named by digest. Experimental: this API can change without notice. - name: Weight Sets description: > A weight set is a version-2 weights bundle, named by its set digest. Push the files, then put the manifest. Available when weight sets are enabled for your account. Experimental: this API can change without notice. - name: Tags description: > A tag is a movable name on one model image or one weight set of a project. A release of the model is a read-only tag. Experimental: this API can change without notice. paths: /sessions/{session_id}/runtime: parameters: - $ref: '#/components/parameters/SessionId' get: tags: - Sessions summary: Get where a session runs description: > Returns a smaller view of the session that names where it runs: its state, its placement, and the instance that serves it. `machine_id` is empty until an instance picks up the session, and `cluster_id` is `""` until the session is placed. Only the user who started the session may call this. A session token reads only the sessions bound to it. operationId: getSessionRuntime parameters: - $ref: '#/components/parameters/ApiVersion' responses: '200': description: Where the session runs. content: application/json: schema: $ref: '#/components/schemas/SessionRuntime' example: session_id: 85ded560-014c-42df-8902-89dfbca8fa00 state: ACTIVE cluster_id: 054e2495-c685-450f-9ceb-57f185b7300a zone: us-west machine_id: inst-7f9c2d '400': description: '`session_id` is not a UUID.' content: application/json: schema: $ref: '#/components/schemas/Error' '401': $ref: '#/components/responses/Unauthorized' '403': description: > The caller did not start this session, or the session does not exist. The two answer the same. content: application/json: schema: $ref: '#/components/schemas/Error' security: - apiKey: [] - sessionToken: [] components: parameters: SessionId: name: session_id in: path required: true description: The session's ID, as returned by `POST /sessions`. schema: type: string format: uuid ApiVersion: name: Reactor-API-Version in: header required: false description: >- The API protocol version the client speaks. Currently `1`. Older versions than the server's minimum get `426`. schema: type: string example: '1' schemas: SessionRuntime: type: object required: - session_id - state - cluster_id properties: session_id: type: string format: uuid state: $ref: '#/components/schemas/SessionState' cluster_id: type: string description: An opaque placement ID. `""` until the session is placed. zone: type: string description: The Reactor region serving the session. Omitted when unknown. machine_id: type: string description: >- An opaque ID of the instance serving the session. Absent until an instance picks it up. Error: type: object required: - error properties: error: type: string description: >- A stable error code (for example `not_found`) on newer routes, or a sentence on older ones. When `message` is present, branch on `error`. message: type: string description: >- A human-readable explanation. Do not parse it; its wording may change. resource: type: string description: The type of the resource a `not_found` refers to. reason: type: string description: >- A more specific cause for `failed_precondition`, `aborted`, and some `invalid_request` errors. SessionState: type: string description: The session's lifecycle state. enum: - CREATED - PENDING - WAITING - SUSPENDED - ACTIVE - INACTIVE - CLOSED responses: Unauthorized: description: The credential is missing, invalid, or expired. content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: apiKey: type: http scheme: bearer description: >- A Reactor API key (`rk_...`), sent as `Authorization: Bearer rk_...`. Keep it on a server. sessionToken: type: http scheme: bearer bearerFormat: JWT description: >- A session-scoped JWT minted by `POST /tokens`. Accepted on `/sessions` and `/clips` only. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.