Prediction Markets Events API

Retrieve Octagon's analyzed prediction market events over REST. The Events API exposes two endpoints:

• List events — the latest snapshot of every analyzed event, including model/market probabilities, confidence scores, analysis summaries, and per-market outcome breakdowns.
• Event history — the historical snapshots for a single event by ticker, for time-series analysis and backtesting.

Like the Chat Completions and Responses endpoints, these are direct REST endpoints called relative to the Octagon API base URL:

Base URL

https://api.octagonai.co/v1

List Events

GET /predictions/events

Returns the latest snapshot of every analyzed prediction market event tracked by Octagon, ordered by most recently captured first.

Query Parameters

Parameter	Type	Required	Description
limit	integer	No	Number of records to return. Default 10; minimum 1; maximum 200.
cursor	string	No	Cursor for pagination. Use the cursor returned from a previous response to continue.
has_history	boolean	No	When true, only return events that have multiple historical snapshots available for time-series use.
include	string	No	Comma-separated list of optional per-row field groups. Supported: eligibility (see below).

Response Fields

Each event in the data array includes:

Field	Type	Description
history_id	integer	Unique identifier for this snapshot.
run_id	string (UUID)	The export run that produced this snapshot.
captured_at	string (ISO 8601)	When this snapshot was captured.
event_ticker	string	Ticker identifier for the event.
name	string	Human-readable event name.
slug	string	URL-friendly slug.
image_url	string	Event image URL.
series_category	string	Category (e.g., "Politics", "Crypto", "Economics").
available_on_brokers	boolean	Whether the event is available on supported brokers.
mutually_exclusive	boolean	Whether the event's outcomes are mutually exclusive.
analysis_last_updated	string (ISO 8601)	When the analysis was last refreshed.
confidence_score	float	Octagon's confidence in the model output (0–10 scale).
model_probability	float	Octagon model probability for the event's primary/most-liquid market (0–100 percentage scale). See outcome_probabilities for the full per-market breakdown.
market_probability	float	Market-implied probability for the event's primary/most-liquid market (0–100 percentage scale). See outcome_probabilities for the full per-market breakdown.
edge_pp	float	Model edge in percentage points (model_probability - market_probability).
expected_return	float	Expected return if the model is correct.
r_score	float	Risk-adjusted score.
total_volume	float	Total trading volume.
total_open_interest	float	Total open interest.
close_time	string	When the event closes.
key_takeaway	string	One-line summary of the model's view.
current_state_summary_richtext	string	Rich-text summary of the current state.
short_answer_richtext	string	Rich-text short answer.
executive_summary_richtext	string	Rich-text executive summary.
outcome_probabilities	array	Per-market outcome breakdown (see below). null if unavailable.
has_history	boolean	Whether this event has multiple historical snapshots for time-series analysis.

The response envelope also includes next_cursor and has_more for pagination.

Eligibility fields

Present only when include=eligibility is set:

Field	Type	Description
eligible	boolean | null	Whether a fresh report can be generated for this event.
eligibility_status	string | null	Market state on the marketplace: open, paused, unopened, closed, settled, or unknown.
eligibility_reason	string | null	Human-readable explanation for the eligible value.

Generate fresh reports with the Reports API.

Event History

GET /predictions/events/{event_ticker}/history

Returns historical snapshots for a single prediction market event by its ticker, newest first.

Finding the event ticker in a Kalshi URL. A Kalshi event URL has the form /markets/<series-ticker>/<event-slug>/<event-ticker>. In https://kalshi.com/markets/kxfeddecision/fed-meeting/kxfeddecision-26jun, the event ticker is KXFEDDECISION-26JUN. Market deeplinks end in a market ticker instead, which is the event ticker plus an outcome suffix: strip the suffix to get the event ticker (kxoaianth-40-oai → KXOAIANTH-40).

Query Parameters

Parameter	Type	Required	Description
limit	integer	No	Number of records to return. Default 50; minimum 1; maximum 200.
cursor	string	No	Cursor for pagination. Use the cursor returned from a previous response to continue.
captured_from	datetime (ISO 8601)	No	Start timestamp filter (inclusive) for snapshot capture time.
captured_to	datetime (ISO 8601)	No	End timestamp filter (inclusive) for snapshot capture time.
include	string	No	Set to analysis to include the analysis fields in the response.
days	integer	No	Exclude snapshots where close_time is before now minus this many days. Snapshots with no close_time are always included. Minimum 1.
exclude_empty_model	boolean	No	When true, exclude snapshots where model_probability is null (incomplete analysis). Default true.

Response Fields

Each snapshot in the data array includes:

Field	Type	Description
history_id	integer	Unique identifier for this snapshot.
run_id	string (UUID)	The export run that produced this snapshot.
captured_at	string (ISO 8601)	When this snapshot was captured.
event_ticker	string	Ticker identifier for the event.
name	string	Human-readable event name.
slug	string	URL-friendly slug.
series_category	string	Category (e.g., "Politics", "Crypto", "Economics").
close_time	string	When the event closes.
confidence_score	float	Octagon's confidence in the model output (0–10 scale).
model_probability	float	Octagon model probability for the event (0–100 percentage scale).
market_probability	float	Current market-implied probability (0–100 percentage scale).
edge_pp	float	Model edge in percentage points (model_probability - market_probability).
expected_return	float	Expected return if the model is correct.
r_score	float	Risk-adjusted score.
total_volume	float	Total trading volume.
total_open_interest	float	Total open interest.
outcome_probabilities	array	Per-market outcome breakdown (see below). null if unavailable.

When include=analysis is set, these additional fields are included:

Field	Type	Description
key_takeaway	string	One-line summary of the model's view.
current_state_summary_richtext	string	Rich-text summary of the current state.
short_answer_richtext	string	Rich-text short answer.
executive_summary_richtext	string	Rich-text executive summary.

The response envelope also includes the requested event_ticker, plus next_cursor and has_more for pagination.

outcome_probabilities items

Each item in the outcome_probabilities array represents one market/outcome within the event:

Field	Type	Description
market_ticker	string	Ticker for this specific market/outcome.
outcome_name	string	Human-readable name for the outcome.
model_probability	float	Octagon model probability for this outcome (0–100 percentage scale).
market_probability	float	Market-implied probability for this outcome (0–100 percentage scale).

Use Cases

• Discover all events currently tracked and analyzed by Octagon, or build a catalog/dashboard of active events.
• Monitor the latest model probabilities, confidence scores, and analysis across all events.
• Filter to events with historical data (has_history=true), then drill into each event's time-series via the history endpoint.
• Build time-series views of model vs. market probability for a specific event ticker.
• Backtest signal quality (for example, edge_pp and expected_return) across historical snapshots.
• Backtest multi-outcome events using outcome_probabilities per snapshot.
• Track how confidence and liquidity metrics evolve as an event approaches resolution.

Notes

• On Event History, prefer bounded time windows (captured_from and captured_to) for predictable page sizes.
• Probability and score scales follow the Kalshi Search API conventions.