Framework Availability Detection

Thread-safe, cached framework availability checking for PraisonAI adapters

Check whether optional frameworks and dependencies are installed before you run agents or YAML workflows.

from praisonaiagents import Agent

agent = Agent(name="assistant", instructions="You are a helpful assistant.")
agent.start("Run my task once a framework is available.")

from praisonai import PraisonAI

# PraisonAI picks the first available framework automatically
praison = PraisonAI(agent_file="agents.yaml")
praison.run()

The user runs YAML without naming a framework; PraisonAI probes installed adapters and picks the first available.

How It Works

Quick Start

1. Run YAML — framework auto-detected

   from praisonai import PraisonAI
   
   praison = PraisonAI(agent_file="agents.yaml")
   praison.run()  # uses first available framework (crewai → praisonai → autogen)
   

   ag2 is registered and can be requested explicitly via --framework ag2 or framework: ag2 in YAML, but it is not part of the auto-detect chain because its adapter is an unimplemented stub. Selecting it explicitly will raise NotImplementedError at run time until a full implementation lands.

2. Probe before selecting a framework

   from praisonai._framework_availability import is_available
   
   if is_available("crewai"):
       print("CrewAI is installed")
   
   frameworks = ["autogen", "autogen_v4", "crewai", "ag2", "langgraph", "openai_agents", "google_adk"]
   available = [fw for fw in frameworks if is_available(fw)]
   print(f"Available: {available}")
   

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API Reference

Function	Signature	Behaviour
is_available(name: str) -> bool	Raises ValueError on unknown name	Cached on first call (double-checked locking under threading.Lock)
invalidate(name: str | None = None) -> None	Pass None to clear the whole cache	Useful in tests that monkey-patch importlib

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Known Probe Names

The following framework names are supported:

Name	Detection Method	Notes
crewai	importlib.util.find_spec("crewai")	Standard probe
autogen	importlib.util.find_spec("autogen")	AutoGen v0.2 package
autogen_v4	find_spec("autogen_agentchat") + find_spec("autogen_ext")	AutoGen v0.4 packages
ag2	Distribution + namespace check	See AG2 Detection below
praisonaiagents	import praisonaiagents	PraisonAI agents framework
praisonai_tools	import praisonai_tools	PraisonAI tools package
agentops	import agentops	AgentOps observability
litellm	import litellm	LiteLLM package
openai	import openai	OpenAI Python client
chromadb	importlib.util.find_spec("chromadb")	Vector store backend; used by ChromaVectorStore
pinecone	importlib.util.find_spec("pinecone")	Vector store backend; used by PineconeVectorStore
qdrant_client	importlib.util.find_spec("qdrant_client")	Vector store backend
weaviate	importlib.util.find_spec("weaviate")	Vector store backend
langgraph	find_spec("langgraph") + find_spec("langgraph.prebuilt")	LangGraph framework
openai_agents	Distribution check + from agents import Runner	OpenAI Agents SDK
google_adk	_google_adk_probe() — three-step: dist check → google.adk spec → Agent import	Google ADK framework; True only when all three steps pass

google_adk detection uses a three-step probe in _google_adk_probe(): (1) importlib.metadata.distribution("google-adk") — the PyPI dist must be installed; (2) importlib.util.find_spec("google.adk") — the namespace must be discoverable; (3) from google.adk.agents import Agent with fallback to from google.adk import Agent. All three must succeed for is_available("google_adk") to return True. Install with pip install 'praisonai-frameworks[google-adk]' or pip install 'praisonai[google-adk]'.

Vector store backends use the same centralized probe registry — praisonai.adapters.vector_stores calls is_available("chromadb") / is_available("pinecone") rather than maintaining its own _check_* helpers.

autogen_v2 is an adapter name registered in FrameworkAdapterRegistry, not a probe name in _framework_availability. The probe name remains autogen (it imports the autogen v0.2 package). Use the adapter’s .is_available() method to test whether a specific adapter will dispatch successfully — it folds in the implemented marker.

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Adapter Availability vs Framework Availability

Two distinct concepts affect whether an AutoGen-family adapter will actually work:

Question	API
”Is the underlying package importable?”	is_available("autogen") from _framework_availability
”Will calling adapter.run(...) actually work?”	AutoGenV4Adapter().is_available() (folds implemented flag)

For AutoGen v0.4 and AG2 today: the package may import successfully, but the adapter still reports False because implemented = False. This is the safety-by-default behaviour added in PR #2086.

from praisonai._framework_availability import is_available

# Package-level check: is the v0.4 package installed?
pkg_available = is_available("autogen_v4")  # True if autogen-agentchat is installed

# Adapter-level check: will dispatch actually work?
from praisonai.framework_adapters.autogen_adapter import AutoGenV4Adapter
adapter_available = AutoGenV4Adapter().is_available()  # False — implemented = False

# pkg_available may be True while adapter_available is False
# Always use adapter.is_available() to test dispatch-readiness

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AG2 Detection Quirk

AG2 ships under the autogen namespace, so is_available("ag2") checks both:

1. importlib.metadata.distribution('ag2') - Ensures AG2 distribution is installed
2. importlib.util.find_spec("autogen") - Ensures autogen namespace is importable

This prevents false positives when only the legacy AutoGen package is installed.

from praisonai._framework_availability import is_available

# This checks both AG2 distribution AND autogen namespace
if is_available("ag2"):
    print("AG2 is properly installed and autogen namespace is available")

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Cache Management

Results are cached indefinitely until explicitly invalidated:

from praisonai._framework_availability import is_available, invalidate

# First call - performs actual import check
result1 = is_available("crewai")  # Slow: actual import

# Subsequent calls - returns cached result
result2 = is_available("crewai")  # Fast: cached

# Invalidate specific framework
invalidate("crewai")
result3 = is_available("crewai")  # Slow: re-checks import

# Invalidate entire cache
invalidate()  # Clear all cached results

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Thread Safety

The availability checker uses double-checked locking under threading.Lock for thread-safe caching:

import threading
from praisonai._framework_availability import is_available

def worker():
    # Safe to call from multiple threads
    return is_available("crewai")

threads = [threading.Thread(target=worker) for _ in range(10)]
for t in threads:
    t.start()
for t in threads:
    t.join()

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Custom Adapter Usage

Plugin authors can use _framework_availability for their is_available() implementations:

from praisonai._framework_availability import is_available
from praisonai.framework_adapters.base import BaseFrameworkAdapter

class MyAdapter(BaseFrameworkAdapter):
    name = "myframework"
    
    def is_available(self) -> bool:
        return is_available("myframework")  # Uses centralized detection

Third-party adapters cannot extend the known probe names at runtime. The _PROBES dict is module-level and not extensible via public API.

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Testing Support

Use invalidate() in tests that mock importlib:

import unittest.mock
from praisonai._framework_availability import is_available, invalidate

def test_framework_detection():
    # Clear any cached results
    invalidate()
    
    with unittest.mock.patch('importlib.util.find_spec', return_value=None):
        assert not is_available("crewai")
    
    # Clear cache again for clean test state
    invalidate()

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Backward-compat constants on praisonai.agents_generator

Six module-level constants are available for backward compatibility and can be imported directly from praisonai.agents_generator.

from praisonai.agents_generator import CREWAI_AVAILABLE, AUTOGEN_AVAILABLE

Constant	Equivalent to
PRAISONAI_TOOLS_AVAILABLE	is_available("praisonai_tools")
CREWAI_AVAILABLE	is_available("crewai")
AUTOGEN_AVAILABLE	is_available("autogen")
AG2_AVAILABLE	is_available("ag2")
PRAISONAI_AVAILABLE	is_available("praisonaiagents")
AGENTOPS_AVAILABLE	is_available("agentops")

For new code, use is_available("crewai") directly rather than importing these constants.

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Best Practices

Prefer adapter.is_available() for dispatch decisions

Package probes (is_available("autogen_v4")) only confirm importability. Use AutoGenV4Adapter().is_available() when you need to know whether execution will actually succeed.

Use invalidate() in tests that mock importlib

Cached results persist for the process lifetime. Call invalidate() before and after monkey-patching importlib so probes re-run cleanly.

Avoid heavy imports inside is_available()

Custom adapters should delegate to is_available() rather than importing large packages on every CLI startup probe.

Use pick_default() instead of manual priority lists

For default framework selection, call FrameworkAdapterRegistry.pick_default() rather than hard-coding probe tuples.

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Related

Framework Adapter Plugins

Creating custom framework adapters

AutoGen Framework

AutoGen framework integration

Google ADK Framework

Google ADK framework integration