> ## Documentation Index
> Fetch the complete documentation index at: https://docs.bayse.markets/llms.txt
> Use this file to discover all available pages before exploring further.

# v0.1.11 — May 5, 2026

> Batch order endpoints and self-trade prevention for CLOB markets

## New endpoints

### Batch place orders — `POST /v1/pm/orders/batch`

Submit up to **50 CLOB orders** in a single round-trip. Orders may span multiple markets and events — each item carries only `outcomeId`, and the server resolves market and event from the outcome. Per-order best-effort: a bad item does not abort the rest of the batch.

```json theme={null}
{
  "orders": [
    { "outcomeId": "...", "side": "BUY",  "type": "LIMIT", "amount": 100, "price": 0.70 },
    { "outcomeId": "...", "side": "SELL", "type": "LIMIT", "amount":  50, "price": 0.32 }
  ]
}
```

See [Batch place orders](/api-reference/pm/batch-place-orders) for the full schema.

***

### Batch cancel orders — `DELETE /v1/pm/orders/batch`

Cancel up to **100 CLOB orders** in a single round-trip. Order IDs may belong to different markets and events. IDs the caller does not own return `ORDER_NOT_FOUND`.

```json theme={null}
{
  "orderIds": [
    "f6a7b8c9-d0e1-2345-fabc-678901234567",
    "a1b2c3d4-e5f6-7890-abcd-ef1234567890"
  ]
}
```

See [Batch cancel orders](/api-reference/pm/batch-cancel-orders) for the full schema.

***

## New features

### Self-trade prevention — `stpMode` on CLOB orders

CLOB order placement now accepts an optional `stpMode` field that controls how the matching engine resolves a match against another resting order from the same user. Previously, both same-user orders sat on the book until one was manually cancelled — a sharp edge for market makers replacing quotes.

```json theme={null}
{
  "side": "BUY",
  "outcomeId": "...",
  "type": "LIMIT",
  "amount": 100,
  "price": 0.71,
  "stpMode": "CANCEL_OLDEST"
}
```

Valid values:

* `SKIP` *(default)* — the match is silently skipped and both orders remain on the book. Backward-compatible behavior.
* `CANCEL_OLDEST` — the resting same-user maker is cancelled and refunded; the taker continues matching against other counterparties.
* `CANCEL_NEWEST` — the incoming taker stops at the same-user match. If it had already filled against other users, those fills stand and the taker comes back as `cancelled`; otherwise it is `rejected`.
* `CANCEL_BOTH` — the resting maker is cancelled and the taker is cancelled or rejected under the same rule as `CANCEL_NEWEST`.

Unknown values fall back to `SKIP`. The applied `stpMode` is echoed back on `OrderDto` / `OrderResponse`, so the client can confirm what the server applied without round-tripping through the request body. AMM orders ignore `stpMode`.

***

## Behavior to know

* **CLOB-only.** Both batch endpoints and `stpMode` apply only to CLOB markets. AMM orders in a batch are rejected per-item with `UNSUPPORTED_ENGINE`; AMM orders ignore `stpMode` entirely.
* **Per-order best-effort.** Batch HTTP responses are `200 OK` whenever the batch was processed. Inspect the per-item `success` flag and the `summary` to see what landed.
* **Weighted rate limiting.** Batches are charged **per item** against your write rate-limit bucket — a 50-order batch costs 50 tokens, not 1. Over-budget batches are rejected with `429` before any orders reach the matching engine.
* **Idempotent retries.** Both batch endpoints accept an optional `Idempotency-Key` header. Retries within 24 hours that share the same key, body, and route replay the original response with `Idempotent-Replayed: true`. Reusing a key with a different body returns `422`; a concurrent retry (sent before the first is finished) returns `409`. Transient responses (`5xx`, `429`, `408`) are not cached so you can recover by retrying.

## Documentation

* New concept page: [Batch orders](/concepts/batch-orders).
* New API references: [Batch place orders](/api-reference/pm/batch-place-orders) and [Batch cancel orders](/api-reference/pm/batch-cancel-orders).
* [Place order](/api-reference/pm/place-order) request and response schemas updated with `stpMode`, including a short market-maker quote-replacement example.