LangStream vs Haystack

Side-by-side — pricing, strengths, tradeoffs, and fit.

LangStream

Event-driven framework for building and running LLM applications with no-code and Python.

Haystack

Build industrial-strength applications with Transformer models and LLMs.

At a glance

Open SourceFree Tier
◌ Declining·From $0
Open SourceFree Tier
● Established·From $0

Overview

One-liner

Event-driven framework for building and running LLM applications with no-code and Python.

One-liner

Build industrial-strength applications with Transformer models and LLMs.

Maturity

Declining

Maturity

Established

Open source

✓ Yes

Open source

✓ Yes

Pricing

Free tier

✓ Available

Open source — free to use

Free tier

✓ Available

Open source — free to use

Starts at

$0

Starts at

$0

Model

Flat rate

Model

Flat rate

Enterprise

✕ None

Enterprise

✕ None

Best for

✓ Best for

Teams looking to build scalable, event-driven LLM applications without extensive coding knowledge
Projects requiring integration with LangChain-based agents for enhanced functionality
Developers who prefer a no-code approach but also need the flexibility of Python scripting

✓ Best for

Teams building RAG apps who need a modular architecture for flexibility
Developers integrating AI into existing applications with Python
Researchers developing custom NLP solutions using Transformer models and LLMs

Not ideal for

✕ Not for

Applications that require real-time streaming capabilities beyond its current architecture
Teams needing cloud-hosted solutions without self-hosting options

✕ Not for

Projects requiring real-time streaming capabilities (batch-only architecture)
Budget-constrained projects that cannot afford the computational resources required for running large language models

Strengths

↑ Strengths

Support for event-driven architecture
Integration with LangChain-based agents
No-code and Python development options
Scalable application building for LLMs

↑ Strengths

Support for Transformer models and LLMs
Question answering system integration
Document search engine capabilities
Modular architecture for flexibility

Weaknesses

↓ Weaknesses

Limited documentation for advanced use cases
Small community and limited third-party integrations

↓ Weaknesses

Limited documentation for advanced use cases
Performance issues with large datasets
Full LangStream profile →Full Haystack profile →