Summary

Adds a new hook event type message:received that fires before a message is processed by the agent. This enables:

• Running custom logic on incoming messages (e.g., memory curation with memfas)
• Injecting context into the message body via injectedContext
• Optionally skipping message processing via skipProcessing

Changes

• src/hooks/internal-hooks.ts: Added MessageReceivedHookContext type and isMessageReceivedEvent() guard
• src/web/auto-reply/monitor/on-message.ts: Wired up hook for WhatsApp channel
• src/hooks/internal-hooks.test.ts: Added 10 new tests (28 total, all passing)

Hook Context

type MessageReceivedHookContext = {
  message: string;
  messageId?: string;
  senderId?: string;
  senderName?: string;
  channel: string;
  chatId?: string;
  isGroup: boolean;
  sessionKey: string;
  agentId: string;
  injectedContext?: string;  // mutable - prepended to message
  skipProcessing?: boolean;  // mutable - skip agent turn
  skipReason?: string;       // mutable - logged if skipped
};

Usage

// hooks/my-hook.js
export default async function(event) {
  if (event.type !== 'message' || event.action !== 'received') return;
  
  // Inject context
  event.context.injectedContext = 'Relevant memory: user likes pizza';
  
  // Or skip processing
  if (isSpam(event.context.message)) {
    event.context.skipProcessing = true;
    event.context.skipReason = 'spam detected';
  }
}

Future Work

• Wire up other channels (Discord, Telegram, Slack, Signal, iMessage)
• The pattern is identical - just add the hook trigger before each channel's dispatch

Closes #7541

Greptile Overview

Greptile Summary

This PR introduces a new internal hook event message:received (type message, action received) with a dedicated context shape and a runtime type guard (src/hooks/internal-hooks.ts). The WhatsApp web auto-reply handler now triggers this hook before calling processMessage(), allowing hooks to request skipping processing or to inject a context prefix into the inbound message (src/web/auto-reply/monitor/on-message.ts). Tests were extended to cover handler registration/triggering and the new isMessageReceivedEvent guard (src/hooks/internal-hooks.test.ts).

Key items to double-check before merging:

• The current injection path mutates msg.body but processMessage() still computes and logs combinedBody separately, so the agent input (RawBody) and the logged/contextual Body can diverge.
• The lockfile now contains two axios snapshot variants; ensure this is intentional and produced by the expected pnpm version/settings.

Confidence Score: 3/5

• This PR is reasonably safe to merge but has a couple of behavioral/consistency concerns worth addressing.
• Core hook plumbing and tests look straightforward, but the WhatsApp wiring currently injects context by mutating msg.body in a way that can diverge from how processMessage() constructs/logs combinedBody, and the pnpm-lock change introduces an additional axios resolution variant that should be verified as intentional.
• src/web/auto-reply/monitor/on-message.ts, pnpm-lock.yaml

_{(2/5) Greptile learns from your feedback when you react with thumbs up/down!}