langchain-edon ·

Runtime governance for LangChain agents. Evaluate and enforce every tool call before it executes — ALLOW, BLOCK, or escalate to a human.

pip install langchain-edon

---

What this does

langchain-edon wraps your LangChain tools so every call goes through EDON before execution. Your agent keeps using tools exactly as before — EDON just intercepts each call and checks it against your policy.

Agent decides to call a tool
         ↓
  EDON evaluates the action
         ↓
  ALLOW → tool executes normally
  BLOCK → EdonBlockedError raised
  HUMAN_REQUIRED → escalation raised

Every decision is logged to a tamper-evident audit trail.

---

Quickstart (2 minutes)

1. Install

pip install langchain-edon langchain-openai

2. Wrap your tools

import os
from langchain_openai import ChatOpenAI
from langchain.agents import AgentExecutor, create_tool_calling_agent
from langchain_core.prompts import ChatPromptTemplate
from langchain_community.tools import DuckDuckGoSearchRun

from langchain_edon import EdonGuard

# Define your tools as normal
tools = [DuckDuckGoSearchRun()]

# Wrap them — same interface, now governed
governed_tools = EdonGuard.wrap_tools(
    tools=tools,
    api_key=os.environ["EDON_API_KEY"],
    agent_id="research-agent",
)

# Build your agent exactly as before
llm = ChatOpenAI(model="gpt-4o-mini")
prompt = ChatPromptTemplate.from_messages([
    ("system", "You are a helpful research assistant."),
    ("human", "{input}"),
    ("placeholder", "{agent_scratchpad}"),
])

agent = create_tool_calling_agent(llm, governed_tools, prompt)
executor = AgentExecutor(agent=agent, tools=governed_tools)

result = executor.invoke({"input": "What is the latest news about AI governance?"})
print(result["output"])
# Every tool call was evaluated by EDON before it ran

---

Two integration patterns

Pattern 1: EdonGuard (enforcing)

Wraps tools so EDON evaluates each call before execution. Blocked actions raise an exception and the tool never runs.

from langchain_edon import EdonGuard
from edon.exceptions import EdonBlockedError, EdonEscalatedError

governed_tools = EdonGuard.wrap_tools(
    tools=[search_tool, email_tool, calendar_tool],
    api_key="your-edon-key",
    agent_id="my-agent",
    raise_on_block=True,   # default — raises EdonBlockedError on BLOCK
)

# Or softer mode — returns error string to LLM instead of raising
governed_tools = EdonGuard.wrap_tools(
    tools=tools,
    api_key="your-edon-key",
    raise_on_block=False,  # LLM sees "[EDON BLOCKED] ..." as tool output
)

Pattern 2: EdonCallbackHandler (audit-only)

Logs all tool calls to EDON without blocking anything. Use for observability and audit trails.

from langchain_edon import EdonCallbackHandler

handler = EdonCallbackHandler(
    api_key=os.environ["EDON_API_KEY"],
    agent_id="my-agent",
    verbose=True,   # prints [EDON] tool_name -> ALLOW (12ms) to stdout
)

executor = AgentExecutor(
    agent=agent,
    tools=tools,           # unmodified tools — not blocked
    callbacks=[handler],   # all calls logged to EDON
)

You can combine both — use EdonGuard for enforcement on high-risk tools and EdonCallbackHandler for full observability:

from langchain_edon import EdonGuard, EdonCallbackHandler

governed = EdonGuard.wrap_tools(
    tools=[email_tool, delete_tool],
    api_key="your-key",
    agent_id="my-agent",
)
handler = EdonCallbackHandler(api_key="your-key", agent_id="my-agent")

executor = AgentExecutor(
    agent=agent,
    tools=governed + [search_tool],   # governed + ungoverned mixed
    callbacks=[handler],
)

---

Handling blocked actions

from edon.exceptions import EdonBlockedError, EdonEscalatedError

try:
    result = executor.invoke({"input": "Delete all user records"})
except EdonBlockedError as e:
    print(f"Blocked: {e.reason}")
    print(f"Code:    {e.reason_code}")     # e.g. "OUT_OF_SCOPE"
    print(f"Audit:   {e.action_id}")       # trace the decision
except EdonEscalatedError as e:
    print(f"Needs human: {e.question}")
    # Send e.question to your human-in-the-loop queue

---

Parameters

Parameter	Default	Description
api_key	EDON_API_KEY env	Your EDON API key
base_url	EDON_BASE_URL or cloud	EDON gateway URL
agent_id	"langchain-agent"	Agent identifier in audit trail
intent_id	None	Pin to a specific intent contract
raise_on_block	True	Raise exception on BLOCK/ESCALATE

---

Environment variables

export EDON_API_KEY=your-key
export EDON_BASE_URL=https://edon-gateway.fly.dev   # or your self-hosted URL
export EDON_AGENT_ID=research-agent                 # optional default

---

Self-hosting

Point at your own EDON gateway:

governed_tools = EdonGuard.wrap_tools(
    tools=tools,
    api_key="your-token",
    base_url="http://localhost:8000",
)

---

Links

• Core SDK: github.com/EDONCORE/edon-python
• Console: edoncore.com/console
• Docs: docs.edoncore.com
• Issues: github.com/EDONCORE/langchain-edon/issues

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License

MIT © EDON Core