AWS Strands - Sakshi Documentation

A Strands Agent runs with a list of hook providers, and the SDK invokes their callbacks around every tool call and model call. Sakshi ships one. SakshiStrandsHooks is a HookProvider: pass it via Agent(hooks=[...]) and every tool and model call is witnessed on the active decision. Turn on enforce and each tool call is routed through the agent’s autonomy envelope before it runs. The provider does not import strands at module load, so it degrades cleanly and carries no version lock.

Install

pip install sakshi-sdk strands-agents

Register the hooks

Pass SakshiStrandsHooks in the agent’s hooks list, and run inside a witness session.

from strands import Agent

agent = Agent(model=model, tools=[check_credit, approve_loan])
agent("Assess this applicant.")

from strands import Agent
from sakshi import SakshiClient
from sakshi.middleware import SakshiStrandsHooks

client = SakshiClient("https://sakshi.your-company.internal", api_key="sks_...")

agent = Agent(
    model=model,
    tools=[check_credit, approve_loan],
    hooks=[SakshiStrandsHooks(client, "loan-decision-agent", enforce=True)],
)

with client.witness("loan-decision-agent", client_ref="APP-2026-04471") as decision:
    agent("Assess this applicant.")
    decision.action(outcome="approved")

What gets witnessed

As the agent runs, the provider records onto the active witness session:

Model calls become llm_call steps with the served model and the finish reason.
Tool calls become tool_call steps with the tool name, the argument keys (never the values, which are tokenized at ingest anyway), and the status. A tool that raises or is cancelled is recorded as such.
The agent invocation is bracketed with agent_start and agent_end.

Enforce in the tool path

With enforce=True, the provider routes each tool call through the agent’s autonomy envelope in BeforeToolCallEvent, before the tool runs. An auto outcome lets the tool proceed; anything else cancels the tool (Strands’ cancel_tool) so it never executes, and a tool_blocked step records why.

hooks = SakshiStrandsHooks(
    client,
    "loan-decision-agent",
    enforce=True,
    exempt_tools=("check_credit",),          # read-only, never gated
    stakes_fields=("amount", "stakes"),       # read stakes from tool input
    confidence_fields=("confidence", "score"),
)

The stakes and confidence signals are read from the tool’s own input by the field names you configure. A read-only tool listed in exempt_tools is never gated.

Enforcement is fail-closed: if Sakshi is unreachable, a governed tool is cancelled rather than run ungoverned. Witnessing is fail-open: a recording problem never breaks the agent, and with no active witness session the provider is a no-op. enforce=True requires the client and the agent id.

Full SDK reference

The client, the witness session, and enforcement.

​Install

​Register the hooks

​What gets witnessed

​Enforce in the tool path

Full SDK reference

Install

Register the hooks

What gets witnessed

Enforce in the tool path