Bot-to-Bot VA Integration: Outbound Callback Not Completing + Architecture Guidance

[HomiK]

Hi everyone,

We are building an external AI agent that needs to communicate with an existing ServiceNow Virtual Agent — reusing the VA's existing topics, workflows, knowledge base and conversation management rather than rebuilding any of that logic externally. The target pattern is:

External AI Agent → existing Santos VA → existing topics / workflows / knowledge → response back to external agent

We are currently validating this through a proof-of-concept script before wiring it into the agent itself. Once the end-to-end pattern is confirmed we will implement the validated approach in production.

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What is working

The POC can successfully submit an inbound request to the VA via /api/sn_va_as_service/bot/integration. We can see the inbound request in the ServiceNow logs. The device_type on the conversation record is recorded as Bot to Bot, confirming the external client can reach the VA.

What is not working

The outbound response from the VA to our callback endpoint is not completing. The outbound message record stays in Pending status with a payload-related error.

Screenshots attached:

- Screenshot 2 — Inbound/outbound logs: inbound received successfully, outbound not completing
- Screenshot 3 — Direction and status of inbound and outbound messages
- Screenshot 2 — Inbound/outbound logs: inbound received successfully, outbound not completing
- Screenshot 3 — Direction and status of inbound and outbound messages
- Screenshot 4 — Inbound message confirming the request reaches the VA correctly
- Screenshot 5 — Outbound record stuck in Pending with payload error

Our current interpretation is that the inbound integration is working but the VA's outbound callback delivery path is failing.

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Questions
1. Routing visibility — How can I see which VA profile and model a conversation is being routed to after a bot-to-bot request? We want to confirm which context profile matched and whether it is using LLM or NLU Keyword.

2. Context profile order — We have multiple VA context profiles with different order values. We set our intended profile to a high order number, but the conversation is still routing to a different default profile instead. How does ServiceNow evaluate context profile order for bot-to-bot sessions — does higher order win, or lower? And how can we force a specific profile to handle bot-to-bot requests?

3. Outbound callback debugging — The outbound message record is created but stays in Pending status and never reaches our callback endpoint. How do we diagnose this on the ServiceNow side? Where should we look — syslog, outbound HTTP logs, MID server, or somewhere else?