Cancel all pending limit orders (legacy DELETE alias).
Deprecated — use POST /v1/cancel-all going forward. The DELETE verb stays live until 2026-08-01 to avoid breaking older SDKs that shipped against it. Responses include X-Deprecation and Sunset headers. Requires confirmation: pass ?confirm=true query parameter OR X-Confirm-Cancel-All: true header (P1-J footgun guard, audit 2026-05-12).
Authorizations
Issue from /v1/keys (or admin-issued for enterprise tier).
Headers
Alternative to ?confirm=true; set to true.
Your PolySimulator API key
Polymarket-CLOB-compat alias for X-API-Key (underscore form). SDK clients ported from Polymarket can authenticate without changing header names. X-API-Key takes precedence when both are provided.
PM-CLOB-compat dashed-form alias for X-API-Key. Same value semantics as POLY_API_KEY but with HTTP-conventional dash separators. Audit P1 (staging audit 2026-05-16 0817 PR #1296): the per-tier middleware accepts both spellings but the auth dependency originally only matched the underscore form — now both work end-to-end.
PM-CLOB-compat: Authorization: Bearer ps_live_... (or ps_test_...) is accepted as an alias for X-API-Key so py-clob-client and other ported SDKs authenticate without header name changes. Bearer JWTs are NOT accepted here — use the dashboard-auth endpoints for those.
Query Parameters
Required (one of confirm=true / X-Confirm-Cancel-All header). Footgun guard — see endpoint description.