@tethora/langchain

LangChain integration for Tethora - the AI agent governance and compliance platform.

Provides a callback handler that enforces policies and automatically logs LLM calls, chain runs, and tool calls. Actions that violate your policies are blocked before they execute.

Install

npm install @tethora/langchain tethora-sdk @langchain/core

Usage

import { Tethora } from 'tethora-sdk';
import { TethoraCallbackHandler } from '@tethora/langchain';
import { ChatOpenAI } from '@langchain/openai';

const tethora = new Tethora({ apiKey: 'your-tethora-api-key' });

const handler = new TethoraCallbackHandler({
  client: tethora,
  sessionId: 'conversation-123', // optional
});

const model = new ChatOpenAI({ model: 'gpt-4' });
const result = await model.invoke('Hello!', {
  callbacks: [handler],
});

Works With Chains and Agents

// Chains
const chain = prompt.pipe(model).pipe(outputParser);
await chain.invoke({ input: '...' }, { callbacks: [handler] });

// Agents with tools
const agent = createReactAgent({ llm: model, tools });
await agent.invoke({ messages: [...] }, { callbacks: [handler] });

Policy Enforcement

Before each LLM call, chain run, and tool call, the handler checks your Tethora policies. If a policy blocks the action, a BlockedError is thrown and the operation is aborted:

import { BlockedError } from '@tethora/langchain';

try {
  await chain.invoke({ input: '...' }, { callbacks: [handler] });
} catch (err) {
  if (err instanceof BlockedError) {
    console.log('Blocked by policy:', err.violations);
  }
}

To disable enforcement and use logging only:

const handler = new TethoraCallbackHandler({
  client: tethora,
  skipCheck: true, // Log only, no policy enforcement
});

What Gets Logged

| Event Type | Actions | Data Captured | |-----------|---------|---------------| | llm_call | llm.start, llm.complete, llm.error, llm.blocked | Model name, prompts, token usage, duration | | chain_run | chain.start, chain.complete, chain.error, chain.blocked | Chain name, inputs, outputs, duration | | tool_call | tool.start, tool.complete, tool.error, tool.blocked | Tool name, input, output, duration |

Configuration

new TethoraCallbackHandler({
  client: tethora,       // Required: Tethora SDK instance
  sessionId: '...',      // Optional: group events by session
  agentId: '...',        // Optional: override default agent ID
  skipCheck: false,      // Optional: set true to disable policy enforcement
});

Links

• Documentation
• tethora-sdk

Licence

MIT