crewai_persistence_firestore 0.1.0

Google Firestore persistence backend for CrewAI Flows with built-in message pruning via agentstate-reducer

crewai-persistence-firestore

Google Firestore persistence backend for CrewAI Flows. Persists flow state between runs so your flows can resume from any prior step.

What makes this different: it has message history pruning built in. Pass a MessageReducer and the persistence layer automatically caps your message list before writing to Firestore — no extra code in your flow, no state class changes required. This is the only CrewAI Firestore persistence backend with this capability.

Features

• Full flow state persistence — save and load CrewAI flow state in Google Firestore
• Built-in message pruning — optional MessageReducer prunes message history at the persistence layer, keeping documents lean without changing your flow code
• Pydantic and dict state — works with both BaseModel-based and plain-dict flow states
• Zero schema setup — Firestore collections are created automatically on first write
• Single document per flow — one Firestore document per flow_uuid, easy to inspect and query

Installation

pip install crewai-persistence-firestore

With optional message pruning support:

pip install "crewai-persistence-firestore[reducer]"

Requires Python 3.10+

Firestore Setup

The saver uses Google Cloud Application Default Credentials. Set up auth with one of:

# Local development — authenticate with your Google account
gcloud auth application-default login

# Service account (CI / production)
export GOOGLE_APPLICATION_CREDENTIALS="/path/to/service-account-key.json"

Your Firestore instance must be in Native mode (not Datastore mode). Collections are created automatically on first write — no manual setup required.

Quick Start

Normal flow (dict or Pydantic state)

from crewai.flow.flow import Flow, listen, start
from crewai.flow.persistence import persist_flow
from crewai_persistence_firestore import FirestoreFlowPersistence

persistence = FirestoreFlowPersistence(
    project_id="my-gcp-project",
    collection="flow_states",
)

@persist_flow(persistence=persistence)
class MyFlow(Flow):
    @start()
    def step_one(self):
        return {"status": "started", "counter": 1}

    @listen(step_one)
    def step_two(self, state):
        return {**state, "counter": state["counter"] + 1}

flow = MyFlow()
result = flow.kickoff()

Conversational flow with message pruning

from crewai.flow.flow import Flow, listen, start
from crewai.flow.persistence import persist_flow
from agentstate_reducer import MessageReducer
from agentstate_reducer.models import ReducerConfig
from crewai_persistence_firestore import FirestoreFlowPersistence

reducer = MessageReducer(config=ReducerConfig(min_messages=10, max_messages=20))

persistence = FirestoreFlowPersistence(
    project_id="my-gcp-project",
    collection="flow_states",
    reducer=reducer,
    messages_key="messages",   # key in state that holds the message list
)

@persist_flow(persistence=persistence)
class ChatFlow(Flow):
    @start()
    def chat(self):
        # messages accumulate here; pruning happens automatically at save time
        ...

API Reference

FirestoreFlowPersistence(project_id, collection, reducer, messages_key)

Parameter	Type	Default	Description
project_id	str	required	Google Cloud project ID
collection	str	"flow_states"	Firestore collection name
reducer	MessageReducer	None	Optional pruner — see Message Pruning
messages_key	str	"messages"	Key in the state dict that holds the message list

Methods

Method	Description
init_db()	No-op — Firestore needs no schema setup
save_state(flow_uuid, method_name, state_data)	Persist flow state; applies reducer if configured
load_state(flow_uuid)	Load state dict for the given flow UUID; returns None if not found

Built-in Message Pruning

Long-running conversational flows accumulate message history with every turn. Left unchecked this inflates Firestore document size and eventually blows past LLM context limits.

This persistence backend solves that at the storage layer: pass a MessageReducer and it automatically prunes the message list inside save_state() before writing to Firestore. Your flow code, state class, and node logic stay untouched.

Install with reducer support

pip install "crewai-persistence-firestore[reducer]"

Usage

from agentstate_reducer import MessageReducer
from agentstate_reducer.models import ReducerConfig
from crewai_persistence_firestore import FirestoreFlowPersistence

reducer = MessageReducer(config=ReducerConfig(min_messages=10, max_messages=20))

persistence = FirestoreFlowPersistence(
    project_id="my-gcp-project",
    reducer=reducer,
    messages_key="messages",
)

When len(messages) > max_messages, the oldest human/ai messages are removed until min_messages remain. The following are never pruned:

• Index 0 (typically the system prompt) — controlled by preserve_first=True
• system and function messages
• tool messages — unless their parent ai message is pruned (cascade behaviour, configurable)

See agentstate-reducer on PyPI for full configuration: preserve_first, cascade_tool_messages, summarize_fn, and role alias support (user/assistant/agent).

Data Model

Each flow run is stored as a single Firestore document:

{collection}/
  {flow_uuid}          ← one document per flow run

The document contains all state fields plus two metadata fields added by the persistence layer:

Field	Description
_method_name	Name of the flow method that triggered the save
_saved_at	ISO 8601 UTC timestamp of the last save

Example document:

{
  "user_id": "kamal",
  "messages": [...],
  "step_output": "some result",
  "_method_name": "process_input",
  "_saved_at": "2025-06-30T10:15:00.123456+00:00"
}

License

MIT