OpenBox LangChain SDK — Python

LangChain-Core adapter for OpenBox governance. Provides callback handlers that emit tool and LLM lifecycle events to OpenBox Core's policy engine, enabling real-time governance, guardrails, HITL approval flows, and base-SDK hook governance (HTTP/DB/File I/O) for LangChain agents.

Installation

pip install openbox-langchain-sdk-python

Quick Start

from langchain.agents import create_agent
from openbox_langchain import create_openbox_langchain_middleware

# 1. Create middleware
middleware = create_openbox_langchain_middleware(
    api_url="https://core.openbox.ai",
    api_key="obx_live_...",
    agent_did="did:aip:...",
    agent_private_key="...",
    agent_name="MyAgent",
)

# 2. Create agent with middleware
agent = create_agent(
    model="openai:gpt-4o",
    tools=[...],
    middleware=[middleware],
)

# 3. Invoke — governance applied automatically
result = agent.invoke({"messages": [("user", "your query")]})

How It Works

Two-layer governance architecture:

Core components:

• ActivityBridge — Ownership channel for tool and LLM events; prevents duplicate governance evaluation
• OpenBoxLangChainCoreAsyncCallbackHandler / ...SyncCallbackHandler — LangChain-Core callbacks emitting tool and LLM lifecycle events to OpenBox Core
• AgentMiddleware (for create_agent) — Wraps model and tool calls with additional governance context

Configuration

middleware = create_openbox_langchain_middleware(
    api_url="https://core.openbox.ai",  # OpenBox Core URL
    api_key="obx_live_...",              # API key (obx_live_* or obx_test_*)
    agent_did="did:aip:...",             # Required by default; can use OPENBOX_AGENT_DID
    agent_private_key="...",             # Required by default; can use OPENBOX_AGENT_PRIVATE_KEY
    agent_name="MyAgent",                # Agent name (from dashboard)
    governance_timeout=30.0,             # HTTP timeout in seconds
    validate=True,                       # Validate API key on startup
    session_id="session-123",            # Optional session tracking
    tool_type_map={                      # Optional tool classification
        "search_web": "http",
        "query_db": "database",
    },
)

Agent Identity and DID Signing

OpenBox issues each registered agent a decentralized identifier (DID) and private key. DID signing is enabled by default for newly registered agents. The OpenBox UI returns both values when the agent is created. Pass them to the middleware so governance events are signed and attributable to that agent.

You can provide them directly:

middleware = create_openbox_langchain_middleware(
    api_url="https://core.openbox.ai",
    api_key="obx_live_...",
    agent_did="did:aip:...",
    agent_private_key="...",
)

Or set them through the environment:

export OPENBOX_AGENT_DID="did:aip:..."
export OPENBOX_AGENT_PRIVATE_KEY="..."

If DID signing is explicitly disabled for the agent in OpenBox, these values can be omitted. Otherwise, provide both values together.

Supported Agent Types

• create_agent(model, tools, middleware=[...]) — recommended
• Any LangChain agent builder that accepts middleware

Verdict Enforcement

5-tier verdict system:

• ALLOW — Request permitted
• CONSTRAIN — Request constrained (e.g., rate limit)
• REQUIRE_APPROVAL — Human approval required (HITL polling)
• BLOCK — Request blocked with error
• HALT — Entire workflow halted (unrecoverable error)

Requirements

• Python 3.11+
• openbox-sdk-python >= 1.0.0
• langchain-core >= 1.3.3
• LangChain >= 1.0.0 (required only for [agent] extra, which enables create_agent middleware)

API Reference

LangChain-Core callbacks:

• OpenBoxLangChainCoreAsyncCallbackHandler — Async callback handler for tool/LLM lifecycle
• OpenBoxLangChainCoreSyncCallbackHandler — Sync callback handler for tool/LLM lifecycle
• ActivityBridge — Ownership channel for lifecycle event deduplication

AgentMiddleware (optional):

• create_openbox_langchain_middleware() — Creates configured middleware for create_agent

See openbox_langchain.__init__.py for full API export list.

License

MIT