Webhook channel loses responses on timeout — no async/polling support

[jeremy-creator]

Expected Behavior

When a webhook request takes longer than syncTimeoutMs (default 25s), the response should still be retrievable. The webhook channel should support an async>

Actual Behavior

The webhook channel is purely synchronous. When the agent takes longer than 25 seconds (typical for non-trivial requests), waitForResponse resolves null,>

Additionally, phantom_task_create writes tasks to the DB with status: 'queued' but nothing processes the queue, so there's no async alternative.

Relevant code path in webhook.ts:

const timeoutMs = this.config.syncTimeoutMs ?? 25_000;
const responseText = await this.waitForResponse(conversationId, inbound, timeoutMs);

if (responseText === null) {
    return Response.json({ status: "error", message: "Response timeout" }, { status: 504 });
}

A suggested fix: have the webhook return 202 Accepted with a task_id, persist responses in SQLite (webhook_responses table), and add a `GET /webhook?po>

Environment

• OS: Ubuntu 25.10
• Docker version: 28.2.2
• Phantom version: 0.18.2
• Deployment method: Docker
• Model: claude-sonnet-4-6

Logs

# Typical flow: agent works for ~60s, but webhook times out at 25s
[webhook] Channel ready
# ... user sends message via webhook ...
# 25 seconds later, 504 returned to caller
# Agent finishes work ~35s later, result discarded