Release 2026.8
Check August's updates.
Know When Your Pipeline Is Warming Up
Streaming ping events can now include a phase field set to cold_start, which tells you that infrastructure for a newly scaled pipeline replica is still starting up. You can display this state in your client while continuing to ignore ping events as before. For details, see The ping event in Enable Streaming.
Pipeline Dependencies Block
You can now declare a specific Haystack Open Source version and add extra packages directly in your pipeline YAML using the dependencies key. When present, the platform automatically runs the pipeline in an isolated environment with exactly the packages you specify, with no changes needed to how you query the pipeline.
The platform validates the block when you save or deploy a pipeline, so version mismatches are caught early. For details on pipeline YAML, see Building Pipelines.
To learn more about Haystack Open Source and its relation to Haystack Platform, see Haystack Open Source.
Keep Services Active with Scheduled Calls
You can now keep a managed service active with scheduled calls. In a service's Settings > Scheduled calls section, turn on the schedule and set the interval in minutes, an optional query, and optional JSON params.
For details, see Keep a Service Active with Scheduled Calls.
Search Session Now Optional for Chat Queries
When you call the pipeline or deployment /chat endpoint, you no longer have to provide a search_session_id. If you omit it, the platform creates a new search session owned by the pipeline or deployment you're querying and returns its ID in the X-Search-Session-Id response header, matching the existing behavior of the /chat-stream endpoint. You can still pass an existing search_session_id to continue a conversation and keep chat history.
Set the Haystack Version for a Pipeline
Choose the Haystack version your pipeline runs on from the pipeline settings. Go to Pipeline Settings and select a version from the Haystack Version list. Selecting a version pins your pipeline to that release; leaving it unset keeps your pipeline on the default supported version. For details, see Update Pipeline Settings.
Turn Off SSE Keep-Alive Comments for Streaming Requests
Streaming responses periodically send : keep-alive comment lines while a pipeline is idle, so the connection isn't dropped. If your client only parses data: lines and breaks on these comment lines, you can now send the X-Deepset-Stream-Keepalive: off request header on any streaming request to suppress them for that request. Omitting the header, or sending on, keeps the deployment's configured keep-alive behavior unchanged. Sending any other value returns a 400 error.
This header works on the pipeline search-stream and chat-stream endpoints and the deployment search-stream, chat-stream, and chat completions endpoints. For background on streaming responses and event types, see Enable Streaming.
Easier on the Eyes
You can now use the Haystack Platform in dark or light. Click your profile icon and choose your theme: Light, Dark, or System to match your system's settings.
Redesigned Conditional Router
The Conditional Router component has a redesigned drawer editor and canvas card. In the drawer, each route now appears as a sortable If, Else if, or Else block that you edit directly as YAML, with a Valid or Invalid badge that flags issues like malformed Jinja2 delimiters, output type mismatches, and duplicate output names for that specific route. On the canvas, each route gets its own condition row and a dedicated output handle, so it's easier to see how routes map to downstream connections. Renaming or removing a route automatically updates any canvas connections that depend on it.
To try this feature, ask deepset to enable it for your organization. For details, see ConditionalRouter.
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