Usage & Limits - NBQ Docs

How usage is counted

Usage is counted per conversation, keyed by your session_id.

The first call with a new session_id registers the conversation.
Subsequent calls with the same session_id belong to that conversation and are not counted again.
Your current consumption, remaining allowance, and any overage are visible on the Dashboard.

Plan limits

Plans may include a number of conversations per period (monthly or annual). Depending on your contract, overage is either:

Billed — conversations above your allowance are charged at the per-conversation rate.
Blocked — requests return HTTP 429 when the quota is reached.

API field limits

Field	Limit
`session_id`	1–128 characters
`conversation_history`	Up to 50 messages
`conversation_history[].content`	1–2000 characters per message
`context`	Up to 8000 characters
`answered_question_ids`	Up to 200 entries
Conversion `metadata`	Serialised size ≤ 4096 bytes
CSV import file size	Up to 2 MB

Rate limiting

Rate limiting is enforced at the API level. When you exceed it, requests return HTTP 429. Back off and retry with exponential backoff.

Minimum question bank

The API Key tab in the NBQ Studio is locked until your NBQ instance has at least 10 active questions. The API cannot serve traffic until this threshold is met.