Price threshold crossing callback
Fired when an outcome’s price/probability crosses a target level (edge-triggered, fires once per crossing). At least one of min_probability or max_probability is required. Use min_probability (e.g. 0.75) to fire when the price crosses up to ≥ that level; use max_probability (e.g. 0.25) to fire when it crosses down to ≤ that level. Set one_shot to delete the subscription after the first delivery (requires position_ids or condition_ids). Set fire_if_already_past to fire immediately when the first observed price is already past the target. Optional scope filters: condition_ids, position_ids, outcomes, position_outcome_indices (0 = Yes/Up, 1 = No), event_slugs, tags (a market’s tags or category), series_slugs (parent series).
Headers
UUID of the webhook subscription that fired
UUID of this specific delivery attempt (matches envelope id field)
Event name string (e.g. trader_first_trade)
Delivery attempt number (1 = first attempt)
x >= 1HMAC-SHA256 of the raw request body: sha256=<hex>. Present only when the webhook has a secret configured. Verify with: HMAC-SHA256(secret, raw_body_bytes) == hex_part.
^sha256=[0-9a-f]{64}$Body
Webhook delivery envelope. The data field contains the event-specific payload.
Outer envelope for every webhook HTTP POST delivery. The data field contains the event-specific payload. Delivery headers sent with every POST: X-Webhook-ID (subscription UUID), X-Delivery-ID (this attempt's UUID), X-Event-Type (event name string, e.g. trader_first_trade), X-Attempt (attempt number, 1-indexed). When the webhook has a secret configured, X-Webhook-Signature: sha256=<hmac-hex> is also included — compute HMAC-SHA256 over the raw request body using your secret to verify.
UUID of this specific delivery attempt (matches X-Delivery-ID header)
Event name (e.g. trader_first_trade). On test deliveries the suffix _test is appended.
Price-threshold crossing webhook payload
Unix timestamp in milliseconds when this delivery was created
UUID of the webhook subscription that fired (matches X-Webhook-ID header)
Delivery attempt number. 1 = first attempt; increments on each retry.
x >= 1Response
Webhook delivery acknowledged