CrewAI

In multi-agent crews, per-agent identity is the whole point: each member gets its own keys, its own hash chain, and its own trust score — so when something goes wrong you know which agent did it.

One client per crew member

import os
from proofledger import create_client
from crewai import Agent, Task, Crew

def audited(agent_name: str, role: str):
    """A ProofLedger client bound to one crew member's identity."""
    client = create_client(
        api_key=os.environ["PROOFLEDGER_API_KEY"],
        agent_name=agent_name,
        owner="growth-team",
        framework="crewai",
        model="gpt-4.1",
    )
    client.register_agent(name=role)
    return client

researcher_pl = audited("crew-researcher", "Market Researcher")
writer_pl     = audited("crew-writer", "Report Writer")

WF = "wf_market_report_001"

researcher = Agent(
    role="Market Researcher", goal="Find pricing data", backstory="…",
    step_callback=lambda step: researcher_pl.log_decision(
        workflow_id=WF, action=f"Step: {str(step)[:180]}"),
)
writer = Agent(role="Report Writer", goal="Write the report", backstory="…")

# Log the handoff between agents explicitly:
researcher_pl.log_workflow_step(WF, event_type="task_received",
                                action="Research competitor pricing")
crew = Crew(agents=[researcher, writer], tasks=[research_task, write_task])
result = crew.kickoff()

researcher_pl.log_workflow_step(WF, action="Handed findings to writer")
writer_pl.log_workflow_step(WF, status="completed",
                            action="Report delivered")

Note

create_client gives each member an isolated client (its own identity and signing key) while sharing one API key. Both agents appear separately in the registry with their own timelines — and the shared workflow_id stitches the crew's work into one replayable story.

Agent identity →Claude agent example →