> ## Documentation Index > Fetch the complete documentation index at: https://docs.langchain.com/llms.txt > Use this file to discover all available pages before exploring further. # Read Delta Stream > Stream feedback deltas for multiple feedback keys. Returns results in chunks as they become available. Each chunk contains results for one or more feedback keys. Errors for individual chunks are included in the response rather than failing the entire operation. Response format (SSE): event: data data: {"feedback_deltas": {"key1": {session_id: {...}}, ...}, "errors": null} event: data data: {"feedback_deltas": {"key2": {...}}, "errors": null} event: end ## OpenAPI ````yaml /langsmith/langsmith-platform-openapi.json post /api/v1/datasets/{dataset_id}/runs/delta/stream openapi: 3.1.0 info: title: LangSmith description: >+ The LangSmith API is used to programmatically create and manage LangSmith resources. ## Host https://api.smith.langchain.com ## Authentication To authenticate with the LangSmith API, set the `X-Api-Key` header to a valid [LangSmith API key](https://docs.langchain.com/langsmith/create-account-api-key#create-an-api-key). version: 0.1.0 servers: - url: / security: [] tags: - name: run x-group: Tracing - name: runs x-group: Tracing - name: sessions x-group: Tracing - name: tracer-sessions x-group: Tracing - name: datasets x-group: Datasets - name: examples x-group: Datasets - name: evaluators x-group: Evaluation - name: experiment-view-overrides x-group: Evaluation - name: experiments x-group: Evaluation - name: annotation-queues x-group: Feedback & Annotation - name: annotation_queues x-group: Feedback & Annotation - name: feedback x-group: Feedback & Annotation - name: feedback-configs x-group: Feedback & Annotation - name: alert_rules x-group: Monitoring - name: bulk-exports x-group: Monitoring - name: charts x-group: Monitoring - name: commits x-group: Prompts & Playground - name: directories x-group: Prompts & Playground - name: hub_environments x-group: Prompts & Playground - name: playground-settings x-group: Prompts & Playground - name: prompt-webhooks x-group: Prompts & Playground - name: prompts x-group: Prompts & Playground - name: tag-transitions x-group: Prompts & Playground - name: comments x-group: Prompt Hub - name: likes x-group: Prompt Hub - name: optimization-jobs x-group: Prompt Hub - name: ownerships x-group: Prompt Hub - name: repos x-group: Prompt Hub - name: settings x-group: Prompt Hub - name: tags x-group: Prompt Hub - name: integrations x-group: Integrations & Tools - name: mcp x-group: Integrations & Tools - name: mcp_vendors x-group: Integrations & Tools - name: oauth x-group: Integrations & Tools - name: tools x-group: Integrations & Tools - name: gateway-policies x-group: LLM Gateway - name: sandboxes x-group: Sandboxes - name: issues x-group: Issues - name: issues-agent x-group: Issues - name: Organizations x-group: Administration - name: SCIM Tokens x-group: Administration - name: TTL Settings x-group: Administration - name: access_policies x-group: Administration - name: api-key x-group: Administration - name: audit-logs x-group: Administration - name: auth x-group: Administration - name: aws_marketplace x-group: Administration - name: data_planes x-group: Administration - name: me x-group: Administration - name: orgs x-group: Administration - name: service-accounts x-group: Administration - name: tenant x-group: Administration - name: ttl-settings x-group: Administration - name: usage-limits x-group: Administration - name: workspaces x-group: Administration - name: ace x-group: System - name: backfills x-group: System - name: features x-group: System - name: info x-group: System - name: model-price-map x-group: System - name: public x-group: System - name: threads x-group: System - name: agents x-hidden: true - name: beacon x-hidden: true - name: engine-trial - name: fleet - name: fleet auth x-hidden: true - name: fleet credentials x-hidden: true - name: fleet github-app x-hidden: true - name: fleet integrations x-hidden: true - name: fleet mcp x-hidden: true - name: fleet threads x-hidden: true - name: fleet trigger-templates x-hidden: true - name: fleet triggers x-hidden: true - name: fleet usage x-hidden: true - name: fleet_webhooks x-hidden: true - name: health - name: internal x-hidden: true - name: metrics x-hidden: true - name: nps x-hidden: true - name: sandboxes-internal x-hidden: true - name: skills x-hidden: true paths: /api/v1/datasets/{dataset_id}/runs/delta/stream: post: tags: - datasets summary: Read Delta Stream description: |- Stream feedback deltas for multiple feedback keys. Returns results in chunks as they become available. Each chunk contains results for one or more feedback keys. Errors for individual chunks are included in the response rather than failing the entire operation. Response format (SSE): event: data data: {"feedback_deltas": {"key1": {session_id: {...}}, ...}, "errors": null} event: data data: {"feedback_deltas": {"key2": {...}}, "errors": null} event: end operationId: read_delta_stream_api_v1_datasets__dataset_id__runs_delta_stream_post parameters: - name: dataset_id in: path required: true schema: type: string format: uuid title: Dataset Id requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/QueryFeedbackDeltaBatch' responses: '200': description: Successful Response content: application/json: schema: {} '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' security: - API Key: [] - Tenant ID: [] - Bearer Auth: [] components: schemas: QueryFeedbackDeltaBatch: properties: baseline_session_id: type: string format: uuid title: Baseline Session Id comparison_session_ids: items: type: string format: uuid type: array maxItems: 10 minItems: 1 title: Comparison Session Ids feedback_keys: items: type: string type: array maxItems: 100 minItems: 1 title: Feedback Keys filters: anyOf: - additionalProperties: items: type: string type: array propertyNames: format: uuid type: object - type: 'null' title: Filters type: object required: - baseline_session_id - comparison_session_ids - feedback_keys title: QueryFeedbackDeltaBatch description: >- Request schema for batched feedback delta queries with multiple feedback keys. HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type type: object required: - loc - msg - type title: ValidationError securitySchemes: API Key: type: apiKey in: header name: X-API-Key Tenant ID: type: apiKey in: header name: X-Tenant-Id Bearer Auth: type: http description: >- Bearer tokens are used to authenticate from the UI. Must also specify x-tenant-id or x-organization-id (for org scoped apis). scheme: bearer ````