Send params as a JSON object, not as a JSON-encoded string. Use the engine_name of each variable in input_params from List Pricing Engine Parameters as the key.

Omit version, or send 0, to run the default version. A live_ key runs your live engines, and a test_ key runs your sandbox engines.

What comes back

• When offers match, result is a list of offer rows. The keys in each row are the engine_names of the engine's output and derived variables, so they depend on how you set up the engine.
• When no offer matches, the status is still 200 and result is an object: {"message": "No offer found"}. Check whether result is a list before you read offers from it.

Errors that return 200

If the pricing engine itself returns an error, this endpoint still responds with HTTP 200, but the body has no object or result. It looks like this:

{
  "type": "api_error",
  "errors": "pricing engine error"
}

Don't rely on the status code alone. Treat any response that has a type field as an error.

The 404 messages for this endpoint say "decision tree", but they refer to the pricing engine.