Item in conversation-flow-version exceeds size limit

Support Help
1

Hi there,

I am experiencing this error via the API:

Unexpected error: BadRequestError: 400 Item in conversation-flow-version exceeds size limit. Please reduce the size of the data.
{
status: 400,
error: {
status: ‘error’,
message: ‘Item in conversation-flow-version exceeds size limit. Please reduce the size of the data.’
}
}

Could you please advise if there is any way to increase or disable this limit. This is critical for us, as we are building big agents. We are already employing agent swapping strategies to partially mitigate this but it is very cumbersome.

Thanks

2

Thank you for reaching out to Retell AI Support. We’ve received your ticket and our team will respond within 8 hours.

3

Hi, thanks for reaching out, the error you’re seeing is due to a hard size limit on individual conversation flow versions — unfortunately, this is not something that can be increased or disabled at this time.

4

Hi thanks for your reply. Could you comfirm what this limit is exactly - does it only apply to nodes or also edges? Does every element count the same in this system? Etc

Thanks

5

The size limit applies to the entire conversation flow version as a whole. Everything in the flow counts toward the limit with no single element being “more expensive,” including:

  • Nodes (all types — conversation, function, transfer, end, etc.) and their instruction text
  • Edges (transition conditions on each node)
  • Tools defined in the flow
  • Components (local component copies, including their own nodes and tools)
  • Global prompt text
  • Fine-tune examples (conversation and transition examples on each node)
  • Knowledge base references, dynamic variables, and other metadata
6

Thanks! And what is the max number we are meant to be able to have?

7

The limit is 400KB of total serialized data per conversation flow version — it’s not expressed as a specific number of nodes or edges. Since different elements vary in size (e.g., a node with a long instruction prompt takes more space than one with a short prompt), there’s no fixed “max number” of elements. In practice, the biggest contributors to size tend to be:

  • Long instruction/prompt text in nodes
  • Many fine-tune examples (conversation and transition examples)
  • Large numbers of edges with complex conditions
  • Tools with detailed descriptions