outcomePrices in events.retrieve returns bid/ask spread, not per-outcome mid-prices

[jasonwdon]

SDK Version

0.1.2

Python Version

3.11.4

Operating System

macOS

Description

The outcomePrices field returned by client.events.retrieve() does not contain per-outcome prices. Instead, it contains a bid/ask pair (best bid and best ask from the order book), making the field name misleading and inconsistent with client.markets.retrieve(), which correctly returns a mid-price per outcome that sums to ~1.

Steps to Reproduce

from polymarket_us import PolymarketUS

client = PolymarketUS(key_id=..., secret_key=...)

event = client.events.retrieve(16521)  # Netherlands vs. Japan
markets = event['event']['markets']

market = markets[1]  # a spread/total/prop market
print(market['outcomes'])       # '["No","Yes"]'
print(market['outcomePrices'])  # '["0.2700","0.2800"]' — sums to 0.55, not ~1

# Compare with markets.retrieve for the same market
full = client.markets.retrieve(market['id'])
print(full['market']['outcomePrices'])  # e.g. '["0.7250","0.2750"]' — sums to 1

Expected Behavior

outcomePrices returns one price per outcome ([noPrice, yesPrice]) summing to approximately 1, consistent with markets.retrieve.

Actual Behavior

outcomePrices returns two values that appear to be the best bid and ask for a single outcome token (e.g., ["0.2700", "0.2800"]), summing to ~0.55 instead of ~1. The field is misleading as it does not reflect the probability/price of each outcome.

Code Sample

[Nexory]

For what it's worth, this doesn't look like an SDK transformation. events.retrieve() (and retrieve_by_slug) just return the raw /v1/events/{id} response without touching the payload (polymarket_us/resources/events.py), and outcomePrices isn't referenced anywhere in the client or modeled in polymarket_us/types/events.py, so the field is passed through verbatim from the API.

That means the difference you're seeing (events giving a ["0.2700", "0.2800"] bid/ask pair vs markets giving ["0.7250", "0.2750"] per-outcome prices) comes from the two API endpoints populating outcomePrices differently, not from the client reshaping it. So it looks like an API-side representation question rather than something fixable in the SDK layer.

If the events endpoint is meant to return per-outcome mid-prices the way /v1/markets does, that would be a backend change; if it intentionally returns the primary token's bid/ask, a short note on the field semantics in the docs/types would save the next person the same confusion.