Haystack: what’s new in v3.4.1 and our verdict
Apache-2.0 Python framework for building search, RAG and agent pipelines, maintained by deepset.
At a glance
- Evidence
- Tested (smoke test)
- Released
- Oct 21, 2026
- Last verified
- Oct 25, 2026
- Pricing
- Official page, dated
- Best for
- agent building
Evidence and ranking
Evidence behind this verdict
- Sources read2 cited sources, latest fetched Oct 25, 2026. (done)
- Facts re-checkedLast verified Oct 25, 2026. (done)
- Run by usSmoke test on Oct 25, 2026 (scope below). (done)
Passed Test log result: Passed. Read the log
Where we rank it (editorial)
Listed here but not yet ranked. Ranks are editorial picks, not benchmark scores.
Pricing: Open-source library; costs come from the model APIs you call. (checked 2026-10-25)
Our verdict
Apache-2.0 Python framework for building search, RAG and agent pipelines, maintained by deepset.
Good for
- Production RAG pipelines
- Teams that like explicit pipeline components
Skip if
- You want a visual builder
Tested. Tested 2026-10-25 (America/Chicago). Haystack 3.4.1 passed our one-tool task on a local 3B model: 3 of 3 trials; cold uv install 2.3 s. Test environment: Linux x86_64 virtual machine (Debian 13), 8 vCPU, 15 GiB RAM, no GPU; no vendor account, login or API key. Agent tools were pointed at a local open-weight model (Qwen2.5-3B-Instruct (Q4_K_M) through Ollama 0.40.11), so we tested the tool, not any vendor's hosted models. Not tested: Any vendor-hosted model: everything ran on a local 3B model, so tool-call reliability with frontier models is not measured here; Multi-agent flows, memory, long conversations, streaming, tracing and cloud deployment; Anything beyond one tool and one question; three trials is a smoke test, not a benchmark; Document stores, retrieval pipelines and evaluation. These are smoke tests, not a benchmark. Full log: /tests/haystack.
Full test log with exact commands, versions and raw output: Haystack 3.4.1: our test log.
- Evidence
- Tested (smoke test, 2026-10-25, local 3B model (Qwen2.5-3B)). A smoke test is not a benchmark.
- What we ran
- Haystack 3.4.1 passed our one-tool task on a local 3B model: 3 of 3 trials; cold uv install 2.3 s.
- Model used
- Qwen2.5-3B-Instruct (Q4_K_M) through Ollama 0.40.11
- Environment
- Linux x86_64 virtual machine (Debian 13), 8 vCPU, 15 GiB RAM, no GPU; no vendor account, login or API key
- Not tested
- Any vendor-hosted model: everything ran on a local 3B model, so tool-call reliability with frontier models is not measured here; Multi-agent flows, memory, long conversations, streaming, tracing and cloud deployment; Anything beyond one tool and one question; three trials is a smoke test, not a benchmark; Document stores, retrieval pipelines and evaluation.
- Date
- (America/Chicago)
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Best for
- Best AI tool for agent building: Open-source Python framework for RAG and agent pipelines.
Key facts
Haystack's repository is Apache-2.0 licensed with v3.4.1 tagged Oct 21, 2026 and a push on Oct 24, 2026.
- License: Apache-2.0 (per GitHub)
- Platforms: Python
- Pricing model: Free and open source
- Free tier: Free to self-host
- Paid plans: None listed for the library
- GitHub: deepset-ai/haystack: 26,842 stars on 2026-10-25, last push 2026-10-24
- Latest release we saw: v3.4.1, 2026-10-21
- How to start: Install haystack-ai with pip and follow the quickstart in the docs.
- v3.4.1 (2026-10-21): the newest release listed on the official page or repository when we read it on 2026-10-25.
How to set it up: Get started with Haystack
These steps come from the vendor's own pages as read on 2026-10-25. We ran Haystack on 2026-10-25; the test log lists what was and was not covered.
Get access
Install haystack-ai with pip and follow the quickstart in the docs.
Check the limits and costs first
Free to self-host. Open-source library; costs come from the model APIs you call.
Pros and cons
Pros
- Apache-2.0
- Active releases
Cons
- Python only
- Our test was one small task on a local 3B model; it does not show behaviour with hosted models or larger jobs
Alternatives and comparisons
- LlamaIndex: Open-source data framework for retrieval-augmented generation and document-centred agents, with a hosted document platform alongside.
- LangChain: Open-source framework for building LLM applications and agents in Python and JavaScript, from the team behind LangGraph and LangSmith.
- Dify: Open-source platform for building LLM apps and agent workflows with a visual canvas; licensed under a modified Apache 2.0 with extra conditions.
- Langflow: MIT-licensed visual builder for AI agents and MCP servers with a very large GitHub following.
FAQ
What is Haystack?
Haystack's repository is Apache-2.0 licensed with v3.4.1 tagged Oct 21, 2026 and a push on Oct 24, 2026.
Is Haystack free?
Free to self-host. Open-source library; costs come from the model APIs you call. Checked 2026-10-25; prices change, so confirm on the vendor's page.
What license is Haystack under?
Its license: Apache-2.0 (per GitHub). Read from the project's own pages on 2026-10-25.
What we have not verified
- Hosted platform pricing
Sources
- Haystack (fetched 2026-10-25)
- Haystack repository (GitHub) (fetched 2026-10-25)
Last verified · Agentic Weekly
Related tools
How to cite this page
Agentic Weekly, "Haystack v3.4.1: what's new, verdict & setup", last updated 2026-10-25, https://theagenticweekly.com/tools/haystack
Keep the Reported or Tested label when you quote a verdict. Plain-text version: https://theagenticweekly.com/tools/haystack.md. More for AI assistants: /ai, /tools.json, /llms.txt.
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