Function writeMessages

source code/bridge/replBridge.ts:1696–1758

(messages)

    },
    sessionIngressUrl,
    writeMessages(messages) {
      // Filter to user/assistant messages that haven't already been sent.
      // Two layers of dedup:
      //  - initialMessageUUIDs: messages sent as session creation events
      //  - recentPostedUUIDs: messages recently sent via POST
      const filtered = messages.filter(
        m =>
          isEligibleBridgeMessage(m) &&
          !initialMessageUUIDs.has(m.uuid) &&
          !recentPostedUUIDs.has(m.uuid),
      )
      if (filtered.length === 0) return

      // Fire onUserMessage for title derivation. Scan before the flushGate
      // check — prompts are title-worthy even if they queue behind the
      // initial history flush. Keeps calling on every title-worthy message
      // until the callback returns true; the caller owns the policy.
      if (!userMessageCallbackDone) {
        for (const m of filtered) {
          const text = extractTitleText(m)
          if (text !== undefined && onUserMessage?.(text, currentSessionId)) {
            userMessageCallbackDone = true
            break
          }
        }
      }

      // Queue messages while the initial flush is in progress to prevent
      // them from arriving at the server interleaved with history.
      if (flushGate.enqueue(...filtered)) {
        logForDebugging(
          `[bridge:repl] Queued ${filtered.length} message(s) during initial flush`,
        )
        return
      }

      if (!transport) {
        const types = filtered.map(m => m.type).join(',')
        logForDebugging(
          `[bridge:repl] Transport not configured, dropping ${filtered.length} message(s) [${types}] for session=${currentSessionId}`,
          { level: 'warn' },
        )
        return
      }

      // Track in the bounded ring buffer for echo filtering and dedup.
      for (const msg of filtered) {
        recentPostedUUIDs.add(msg.uuid)
      }

      logForDebugging(
        `[bridge:repl] Sending ${filtered.length} message(s) via transport`,
      )

      // Convert to SDK format and send via HTTP POST (HybridTransport).
      // The web UI receives them via the subscribe WebSocket.
      const sdkMessages = toSDKMessages(filtered)
      const events = sdkMessages.map(sdkMsg => ({