ag2ai/faststream

Health v2 · maintenance only

Adoption not part of the score

5316 stars · 383 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

FastStream is an asynchronous Python framework for building event-driven applications on top of message brokers like Kafka, RabbitMQ, NATS, Redis, and MQTT. It provides decorator-based producers/consumers, Pydantic or msgspec validation, dependency injection, in-memory testing without a broker, OpenTelemetry/Prometheus observability, and automatic AsyncAPI documentation generation.

Use cases

• build kafka consumers in python
• produce and consume rabbitmq messages with validation
• generate asyncapi docs from code
• test message handlers without a running broker
• build streaming microservices with nats jetstream
• add opentelemetry tracing to message consumers
• integrate kafka subscribers into a fastapi app
• publish test messages to a broker from the cli

When to choose

• you want FastAPI-style ergonomics for message brokers instead of HTTP
• you need AsyncAPI contracts generated automatically from handlers
• you want broker-agnostic code across Kafka, RabbitMQ, NATS, Redis, and MQTT
• you need broker testing in CI without containers
• you want built-in observability middleware for event-driven services

When to avoid

• you need a broker not covered by Kafka, RabbitMQ, NATS, Redis, or MQTT
• you want a heavy streaming platform with built-in state stores or stream processing engines like Flink
• your project is synchronous and cannot use asyncio
• you need direct low-level control and prefer raw broker clients

Facets

framework · maturity active

message-queue serialization testing api-framework middleware tracing monitoring cli documentation microservices backend developer-tools python cross-platform cli kafka rabbitmq nats redis-streams mqtt asyncapi event-driven pydantic msgspec fastapi-integration opentelemetry stream-processing messaging data-engineering docker

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markdown · JSON · MCP: product_card(name="ag2ai/faststream")