> ## Documentation Index > Fetch the complete documentation index at: https://api.csboard.com/llms.txt > Use this file to discover all available pages before exploring further. # Buy listings from your balance > Buy 1–10 listings by id, debited from your CSBoard balance. Requires trading enabled on the key + a linked Steam account and trade URL. Buys are charged at the LIVE price at execution; always send `max_price_usd` as an atomic overcharge ceiling. Idempotent via the `Idempotency-Key` header or `idempotency_key` in the body. ## OpenAPI ````yaml /openapi.json post /orders openapi: 3.1.0 info: title: CSBoard API version: 1.0.0 description: >- Market data over the CSBoard marketplace — live listings, floats, stickers, minAsk prices, FX rates — plus opt-in buying straight from your balance. Free to read, key-gated, built for automation. contact: name: CSBoard url: https://csboard.com/docs servers: - url: https://csboard.com/v1 description: Production security: - bearerAuth: [] tags: - name: Status description: Liveness and freshness probes. - name: Market data description: Read the live catalog, prices, and FX rates. - name: Trading description: Buy listings from your CSBoard balance. Opt-in, key-gated. - name: Account description: Your balance, settled funds, and trading status. paths: /orders: post: tags: - Trading summary: Buy listings from your balance description: >- Buy 1–10 listings by id, debited from your CSBoard balance. Requires trading enabled on the key + a linked Steam account and trade URL. Buys are charged at the LIVE price at execution; always send `max_price_usd` as an atomic overcharge ceiling. Idempotent via the `Idempotency-Key` header or `idempotency_key` in the body. operationId: createOrder parameters: - name: Idempotency-Key in: header description: >- Optional. A retried request with the same key replays the original order instead of buying twice. schema: type: string requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/OrderRequest' example: item_ids: - itm_8841201 - itm_8841340 max_price_usd: 30 idempotency_key: 6f9c2b10-1a2b-4c3d-8e4f-5a6b7c8d9e0f responses: '200': description: Order accepted and debited. content: application/json: schema: $ref: '#/components/schemas/OrderCreated' example: order_id: ord_01J9Z3K8Q2 status: processing items: - item_id: itm_8841201 charged_usd: 14.37 delivery: hold - item_id: itm_8841340 charged_usd: 12.1 delivery: instant total_charged_usd: 26.47 balance_after_usd: 73.53 created_at: '2026-06-29T17:12:04Z' '400': description: Invalid request (e.g. price moved past your ceiling). content: application/json: schema: $ref: '#/components/schemas/Error' examples: price_moved: summary: Live price exceeded max_price_usd value: code: price_moved message: Live total 31.20 exceeds max_price_usd 30.00. current_total_usd: 31.2 '401': $ref: '#/components/responses/Unauthorized' '402': description: Insufficient balance. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: insufficient_balance message: Balance 10.00 is below order total 26.47. '403': description: Trading not enabled on this key. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: trading_not_enabled message: Enable buying for this key in your profile. '429': $ref: '#/components/responses/RateLimited' components: schemas: OrderRequest: type: object properties: item_ids: type: array items: type: string minItems: 1 maxItems: 10 uniqueItems: true description: >- 1–10 unique ids from /v1/listings. Some items can't be combined in a single order — if so the order is rejected and you can split it. max_price_usd: type: number description: >- Total ceiling in USD. Strongly recommended — your overcharge protection, enforced atomically inside the locked debit. idempotency_key: type: string description: >- Optional; or send the Idempotency-Key header. Replays the original order on retry. required: - item_ids OrderCreated: type: object properties: order_id: type: string status: type: string enum: - processing - completed - failed items: type: array items: type: object properties: item_id: type: string charged_usd: type: number delivery: type: string enum: - instant - hold total_charged_usd: type: number balance_after_usd: type: number created_at: type: string format: date-time required: - order_id - status - total_charged_usd Error: type: object description: >- All errors return { code, detail }. Some carry extra fields (e.g. price_moved adds current_total_usd, insufficient_balance adds required_usd/current_usd). properties: code: type: string description: >- Machine-readable error code, e.g. rate_limit_exceeded, trading_not_enabled, price_moved. detail: type: string description: Human-readable explanation. required: - code responses: Unauthorized: description: Missing or invalid API key. content: application/json: schema: $ref: '#/components/schemas/Error' example: code: unauthorized message: Missing or invalid API key. RateLimited: description: Rate limit exceeded. Includes a Retry-After header. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer content: application/json: schema: $ref: '#/components/schemas/Error' example: code: rate_limit_exceeded message: Too many requests. securitySchemes: bearerAuth: type: http scheme: bearer description: >- Send your key as a Bearer token on every request: `Authorization: Bearer csb_pub_...`. Generate keys in your CSBoard profile. ````