Telephony · Custom HTTP guide · Voice URL webhook + Status Callback

Northsun + Twilio

Twilio's documented Voice URL webhook and Status Callback webhook cover raw TwiML telephony — no assistant, no agent concept, no vendor LLM. This guide maps those two events to Mnemix's frozen caller-memory API through your own server; it is a custom HTTP guide, not a native or certified adapter.

What

Mnemix is the memory and enrichment layer for AI agents. Governed context intelligence is the differentiator.

Who

For teams building voice, chat, coding, and workflow agents that need persistent, inspectable context.

Price

Hobby is $0. Paid access is Contact sales.

How

Use the frozen caller REST contract for recall, durable call write-back, and read-only caller lookup. Use authenticated MCP only for the broader beta context tools enabled and proven for your tenant.

For agents

On an inbound call your voice agent receives the caller profile, this tenant's prior-call memory, and available Trestle and Twilio Lookup enrichment as contextual evidence before its first sentence; after hangup the call is submitted and committed durably before the response returns, visible on the very next read.

What Northsun adds to Twilio

• A caller-memory lookup you control. Your Voice URL handler decides when to call Mnemix and what to do with the response — there is no vendor response envelope to fill in.
• Explicit normalization. Twilio's form-encoded webhook body maps into the frozen Mnemix request shape; test that mapping with controlled calls before production.
• A proofable boundary. A successful recording proves the exact Voice URL and Status Callback configuration shown; it does not establish a native adapter.

How to connect Twilio to Northsun

1. 1

   Configure the Voice URL

   Point your Twilio phone number's (or TwiML App's) Voice URL at your handler and verify X-Twilio-Signature before trusting the request.

2. 2

   Recall before you build TwiML

   Call POST /v1/recall_and_enrich with the caller's number and CallSid, then use the response to shape the TwiML you return.

3. 3

   Configure the Status Callback

   Point the Status Callback URL at a verified handler and write back only on a terminal CallStatus (completed, busy, failed, no-answer, canceled).

4. 4

   Prove the write-back

   The interaction is committed durably before calls/end responds; retain the Mnemix trace ID and confirm it with a later recall.

Custom HTTP pattern

Adapt this boundary to the current vendor payload and verify it with controlled events before production.

async function callMnemix(path: string, body: unknown) {
  const response = await fetch(`https://mcp.mnemix.ai${path}`, {
    method: "POST",
    headers: {
      Authorization: `Bearer ${process.env.MNEMIX_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify(body),
  });

  if (!response.ok) {
    throw new Error(`Mnemix request failed: ${response.status}`);
  }

  return response.status === 204 ? undefined : response.json();
}

// In your Voice URL webhook handler, after verifying X-Twilio-Signature:
const packet = await callMnemix("/v1/recall_and_enrich", {
  phone_number: callerNumber,
  trigger: "answered",
  session_id: callSid,
});

// Return your own TwiML using packet.caller / packet.memory here.

// In your verified Status Callback handler, on a terminal CallStatus:
await callMnemix("/v1/calls/end", {
  phone_number: callerNumber,
  session_id: callSid,
  duration_s: durationSeconds,
  outcome: mappedOutcome,
});

FAQ

Is this a native Twilio integration?

No. It is a custom HTTP mapping between documented Twilio webhook capabilities and Mnemix's frozen REST endpoints.

Does Twilio send a transcript?

No. Twilio's Status Callback carries no transcript field — Twilio does not perform ASR on this path. Pass your own transcript only if your application assembled one.

Is this the same as the enrichment vendor Twilio Lookup?

No. Twilio Lookup is a caller-ID enrichment vendor Mnemix calls server-side on every recall. This guide is for wiring raw Twilio telephony (TwiML/Media Streams) itself, a separate integration.

Last updated: 2026-08-18.