> ## Documentation Index > Fetch the complete documentation index at: https://docs.credibledata.com/llms.txt > Use this file to discover all available pages before exploring further. # Stream package change events (SSE) > Opens a Server-Sent Events (SSE) stream of file-change events for the package, used by in-package HTML data apps (via the publisher.js runtime) to live-reload when their sources are edited. This is a long-lived `text/event-stream` connection, not a JSON endpoint, and is therefore not surfaced through the generated API clients — consume it with an `EventSource`. The stream emits: - `event: hello` (`data: connected`) once on connect. - `event: mode` (`data: enabled|disabled`) reporting whether watch mode is currently active for the environment. When `disabled`, no `changed` events will follow until watch mode is started. - `event: changed` (`data: changed`) each time a watched file in the package changes. - periodic `: heartbeat` comments to keep idle proxies from closing the connection. ## OpenAPI ````yaml /dataplane-public-api-doc.yaml get /environments/{environmentName}/packages/{packageName}/events openapi: 3.1.0 info: title: Malloy Publisher - Semantic Model Serving API description: > The Malloy Publisher - Semantic Model Serving API provides comprehensive access to Malloy packages and their associated resources. A Malloy package is a directory containing Malloy models (.malloy files), Malloy notebooks (.malloynb files), and embedded databases (.parquet files) with a malloy-publisher.json manifest at the package's root directory. ## Key Features - **Environment Management**: Create and manage environments with their associated packages and connections - **Package Lifecycle**: Full CRUD operations for Malloy packages and their versions - **Model & Notebook Access**: Retrieve and execute Malloy models and notebooks - **Connection Management**: Secure database connection configuration and testing - **Query Execution**: Execute queries against models and retrieve results - **Watch Mode**: Real-time file watching for development workflows ## Resource Hierarchy The API follows a hierarchical resource structure: ``` Environments ├── Connections └── Packages ├── Models ├── Notebooks └── Databases ``` For examples, see the Malloy samples packages (https://github.com/malloydata/malloy-samples) repository. version: v0 servers: - url: https://{organization}.data.credibledata.com/api/v0/ description: Production API server variables: organization: default: demo description: Your organization subdomain security: - bearerAuth: [] tags: - name: publisher description: Publisher status and health check operations - name: environments description: >- Environment lifecycle management including creation, configuration, and deletion of data modeling environments - name: connections description: >- Database connection management for secure data source configuration and access - name: packages description: >- Package management for Malloy data models, including versioning and distribution - name: models description: Malloy model access and compilation operations - name: notebooks description: Malloy notebook access and execution operations - name: pages description: Static HTML pages (in-package data apps) - name: databases description: Embedded database management and access - name: watch-mode description: Real-time file watching for development workflows - name: materializations description: Package-level materializations for persisting Malloy sources paths: /environments/{environmentName}/packages/{packageName}/events: get: tags: - watch-mode summary: Stream package change events (SSE) description: | Opens a Server-Sent Events (SSE) stream of file-change events for the package, used by in-package HTML data apps (via the publisher.js runtime) to live-reload when their sources are edited. This is a long-lived `text/event-stream` connection, not a JSON endpoint, and is therefore not surfaced through the generated API clients — consume it with an `EventSource`. The stream emits: - `event: hello` (`data: connected`) once on connect. - `event: mode` (`data: enabled|disabled`) reporting whether watch mode is currently active for the environment. When `disabled`, no `changed` events will follow until watch mode is started. - `event: changed` (`data: changed`) each time a watched file in the package changes. - periodic `: heartbeat` comments to keep idle proxies from closing the connection. operationId: stream-package-events parameters: - name: environmentName in: path description: Name of the environment required: true schema: $ref: '#/components/schemas/IdentifierPattern' - name: packageName in: path description: Name of the package required: true schema: $ref: '#/components/schemas/IdentifierPattern' responses: '200': description: An open Server-Sent Events stream of change events content: text/event-stream: schema: type: string description: SSE event stream (see endpoint description for event types) '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '404': $ref: '#/components/responses/NotFound' '500': $ref: '#/components/responses/InternalServerError' '503': $ref: '#/components/responses/ServiceUnavailable' components: schemas: IdentifierPattern: type: string pattern: ^[a-zA-Z0-9_-]+$ description: Standard identifier pattern for resource names Error: type: object description: Standard error response format properties: message: type: string description: Human-readable error message describing what went wrong details: type: string description: Additional error details or context required: - message responses: BadRequest: description: >- The request was malformed or cannot be performed given the current state of the system content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: Unauthorized - authentication required content: application/json: schema: $ref: '#/components/schemas/Error' NotFound: description: The specified resource was not found content: application/json: schema: $ref: '#/components/schemas/Error' InternalServerError: description: The server encountered an internal error content: application/json: schema: $ref: '#/components/schemas/Error' ServiceUnavailable: description: > The service is temporarily unable to accept the request. Possible causes: * Initialization or draining state (rolling updates, graceful shutdown). * Memory back-pressure — the publisher's RSS crossed the high-water mark derived from PUBLISHER_MAX_MEMORY_BYTES and PUBLISHER_MEMORY_HIGH_WATER_FRACTION, so new queries are rejected until RSS drops below the low-water mark (PUBLISHER_MEMORY_LOW_WATER_FRACTION). * Per-pod query concurrency cap reached — PUBLISHER_MAX_CONCURRENT_QUERIES in-flight queries are already running on this pod. Clients should retry with backoff; under sustained pressure, scale out, raise PUBLISHER_MAX_MEMORY_BYTES / PUBLISHER_MAX_CONCURRENT_QUERIES, or refine the offending queries. content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: JWT ````