Last updated on Aug 27, 2026

Tags:

• SDK
• LangChain
• Configuration

Options

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Configuration

The LangChain SDK is configured through explicit options passed to create_openbox_langchain_middleware(). In production, load connection and identity values from environment variables in your application code.

Configuration Precedence

Configuration is resolved in this order:

1. Explicit options passed in code
2. OPENBOX_AGENT_DID and OPENBOX_AGENT_PRIVATE_KEY environment fallback when identity options are omitted
3. SDK defaults for optional fields

api_url and api_key are always required as function parameters. Most applications pass them from OPENBOX_URL and OPENBOX_API_KEY.

Environment Variables

Variable	Required	Default	Purpose
OPENBOX_URL	Yes	-	OpenBox Core base URL, passed as api_url
OPENBOX_API_KEY	Yes	-	OpenBox API key, passed as api_key
OPENBOX_AGENT_DID	Yes, unless disabled	-	DID assigned to this OpenBox agent
OPENBOX_AGENT_PRIVATE_KEY	Yes, unless disabled	-	Base64 raw Ed25519 seed returned during identity provision or rotation
OPENBOX_DEBUG	No	false	Enable verbose SDK logging

DID signing defaults

DID signing is enabled by default for newly registered agents in OpenBox. If it has been explicitly disabled for the agent, OPENBOX_AGENT_DID and OPENBOX_AGENT_PRIVATE_KEY can be omitted. Otherwise, provide both values together.

Middleware Parameters

All parameters are passed as keyword arguments to create_openbox_langchain_middleware().

api_url

OpenBox Core API URL.

api_url="https://core.openbox.ai"          # Production
api_url="http://localhost:8000"            # Local dev

api_key

Agent API key issued by OpenBox. Load it from the environment in production:

api_key=os.environ["OPENBOX_API_KEY"]

agent_did and agent_private_key

Agent identity used to sign governance requests. These values default to OPENBOX_AGENT_DID and OPENBOX_AGENT_PRIVATE_KEY.

middleware = create_openbox_langchain_middleware(
    api_url=os.environ["OPENBOX_URL"],
    api_key=os.environ["OPENBOX_API_KEY"],
    agent_did=os.environ["OPENBOX_AGENT_DID"],
    agent_private_key=os.environ["OPENBOX_AGENT_PRIVATE_KEY"],
)

Provide both values together. Passing only one of them fails during SDK configuration.

agent_name

Human-readable name shown in the OpenBox Dashboard.

agent_name="CustomerSupportAgent"

on_api_error

Behavior when OpenBox Core is unreachable or times out:

Value	Behavior
"fail_open"	Allow the operation to proceed and log a warning. Default.
"fail_closed"	Block the operation.

on_api_error="fail_open"    # Default — prioritize availability
on_api_error="fail_closed"  # High-security deployments

governance_timeout

Maximum seconds to wait for a governance evaluation response.

governance_timeout=30.0  # Default
governance_timeout=60.0  # Slower networks
governance_timeout=10.0  # Low-latency requirements

validate

Validate the API key against OpenBox when the middleware is created.

validate=True   # Default
validate=False  # Useful in tests or offline development

session_id

Optional session identifier for grouping runs.

session_id="support-ticket-123"

task_queue

Task queue label included in emitted OpenBox events. Defaults to langchain.

task_queue="customer-support"

tool_type_map

Map LangChain tool names to semantic types. These values can be used by OpenBox policies to target categories of tools rather than individual function names.

tool_type_map={
    "search_web": "http",
    "lookup_customer": "database",
    "send_email": "communication",
}

skip_tool_types

Set of LangChain tool names to exclude from governance evaluation. Use this sparingly for internal logging or health-check tools.

skip_tool_types={"log_metric", "health_check"}

Event Emission Flags

Control which lifecycle events the SDK sends to OpenBox. All default to True.

Parameter	Event sent
send_chain_start_event	WorkflowStarted
send_chain_end_event	WorkflowCompleted
send_tool_start_event	ToolStarted
send_tool_end_event	ToolCompleted
send_llm_start_event	LLMStarted
send_llm_end_event	LLMCompleted

send_llm_start_event=True
send_llm_end_event=True

sqlalchemy_engine

Pre-created SQLAlchemy engine for database governance. When provided, the SDK instruments SQL queries executed through this engine.

from sqlalchemy import create_engine

engine = create_engine(os.environ["DATABASE_URL"])

middleware = create_openbox_langchain_middleware(
    api_url=os.environ["OPENBOX_URL"],
    api_key=os.environ["OPENBOX_API_KEY"],
    agent_did=os.environ["OPENBOX_AGENT_DID"],
    agent_private_key=os.environ["OPENBOX_AGENT_PRIVATE_KEY"],
    sqlalchemy_engine=engine,
)

Full Configuration Example

import os

from langchain.agents import create_agent
from openbox_langchain import create_openbox_langchain_middleware
from sqlalchemy import create_engine

middleware = create_openbox_langchain_middleware(
    api_url=os.environ["OPENBOX_URL"],
    api_key=os.environ["OPENBOX_API_KEY"],
    agent_did=os.environ["OPENBOX_AGENT_DID"],
    agent_private_key=os.environ["OPENBOX_AGENT_PRIVATE_KEY"],
    agent_name="SupportAgent",
    on_api_error="fail_closed",
    governance_timeout=45.0,
    validate=True,
    session_id="support-session",
    task_queue="customer-support",
    tool_type_map={
        "search_web": "http",
        "lookup_customer": "database",
        "send_email": "communication",
    },
    skip_tool_types={"log_metric"},
    send_chain_start_event=True,
    send_chain_end_event=True,
    send_tool_start_event=True,
    send_tool_end_event=True,
    send_llm_start_event=True,
    send_llm_end_event=True,
    sqlalchemy_engine=create_engine(os.environ["DATABASE_URL"]),
)

agent = create_agent(
    model="openai:gpt-4o",
    tools=[search_web, lookup_customer, send_email],
    middleware=[middleware],
)

Next Steps

1. Error Handling — Handle governance decisions in your code
2. Integration Walkthrough — Wire and verify an existing LangChain agent
3. Event Model — Understand the event payloads used by policies and guardrails
4. Troubleshooting — Diagnose configuration and telemetry issues