Place & Manage Orders

PredictBase allows users to place, update, and cancel orders programmatically using authenticated API requests.

All order-related endpoints require a user-bound API key and enforce strict ownership and status checks.

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Authentication

All endpoints on this page require an API key passed via the request header:

x-api-key: YOUR_API_KEY

The API key must be authorized for the user performing the action.

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Create a new Order

Places a new buy or sell order on an existing market.

Endpoint

POST /create-order

Full URL

https://api.predictbase.app/create-order

Request Body

{
  "kind": "NEW_ORDER",
  "order": {
    "type": "LIMIT",
    "side": "BUY",
    "marketId": "10744",
    "optionIndex": 0,
    "qty": 1,
    "price": 0.42,
    "userId": "0xUserAddress",
    "timeInForce": "GTC",
    "receivedAt": 1765595666776
  },
  "meta": {
    "clientOrderId": "ORD#abc123",
    "originalQty": 1
  }

Response (Success)

{
  "success": true,
  "orderId": "ORDER#abc123",
  "status": "RECEIVED"
}

---

Update an Order

Updates the price of an existing order while it is still pending.

Endpoint

POST /update-order

Full URL

https://api.predictbase.app/update-order

Request Body

{
  "orderId": "ORDER#abc123",
  "user": "0xUserAddress",
  "price": 0.42
}

Response (Success)

{
  "success": true,
  "order": {
    "id": "ORDER#abc123",
    "price": 0.42,
    "status": "RECEIVED",
    "updatedAt": "2025-01-01T00:00:00.000Z",
    "...": "other fields"
  }
}

Errors

Status	Meaning
400	Missing orderId, user, or price
409	Invalid status or user mismatch
500	Unexpected server error

---

Cancel an Order

Cancels an existing order that has not been fully filled.

Endpoint

POST /cancel-order

Full URL

https://api.predictbase.app/cancel-order

Response (Success)

{
  "success": true,
  "order": {
    "id": "ORDER#abc123",
    "status": "CANCELED",
    "updatedAt": "2025-01-01T00:00:00.000Z",
    "...": "other fields"
  }

Possible Errors

Status	Meaning
404	Order not found
403	User mismatch
400	Order status not cancelable
409	Order was filled or updated concurrently
500	Unexpected server error

---

View your Orders

Returns a list of user active orders.

Endpoint

GET /get_user_orders/{userAddress}

Full URL

https://api.predictbase.app/get_user_orders/{userAddress}

Response (Success)

[
  {
    "id": "ORDER#6ddcdb08-3147-47ce-8650-e6484e5491d2",
    "marketId": "10001",
    "optionIndex": 0,
    "side": "SELL",
    "type": "LIMIT",
    "qty": 300,
    "filledQty": 0,
    "price": 0.5,
    "maxSlippageBps": null,
    "outcome": "YES",
    "userId": "0x0...",
    "timeInForce": "GTC",
    "status": "RECEIVED",
    "createdAt": "2026-01-03T23:45:24.451Z",
    "updatedAt": "2026-01-03T23:45:24.451Z",
    "__typename": "IntakeOrder"
  },
]

---

Behavior

• The user is resolved from the API key

• Order prices are specified in USD (USDC) dollar value.

  • price = 0.42 means $0.42 USD (42 cents)

  • price = 1.00 means $1.00 USD

  • Prices must be between 0.00 and 1.00

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💡 Common Use Cases

• Trading bots

• Market-making strategies

• Order management dashboards

• Automated re-pricing systems