> ## Documentation Index > Fetch the complete documentation index at: https://docs.arcus.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Get markets > Returns all markets with details, sorted by ascending `marketId`. Optionally filter by market name. ## OpenAPI ````yaml /api-reference/openapi.yml get /v1/markets openapi: 3.1.0 info: title: Arcus API version: 1.0.0 description: > REST API for the Arcus exchange. Provides endpoints for order management, market data, and account onboarding. ## Coming soon (not implemented yet) The following features are declared in this spec (or implied by it) but are **not yet live** on the gateway or matching engine. Schemas and endpoints may be present so clients can wire against the final shape, but today the gateway returns `501 Not Implemented` or the feature is simply absent. Do not depend on these in production until they are announced as live. - **Modify order** (`POST /modifyOrder`) — reduce-only modifications will preserve queue priority; any change that moves the price level or increases size will be handled as an atomic cancel + replace (queue priority is lost). Currently returns `501 Not Implemented`. - **Batch modify order** (`POST /batchModifyOrders`) — same semantics as `modifyOrder`, applied atomically per item. Currently returns `501 Not Implemented`. - **Next predicted funding rate** — the predicted funding rate for the upcoming interval is not yet exposed on `GET /markets` or the markets WebSocket channel. Only the current realized rate is available today. - **Funding rate calculations** — the authoritative calculation methodology (premium sampling window, interest-rate component, clamping, payment schedule) is still being finalized and is not documented here yet. - **Advanced order types** — trailing stop, stop-limit, OCO, and other conditional / bracket order variants beyond plain `LIMIT` and `MARKET` are not yet supported. ## Authentication Order management and credential-creating endpoints require **three** request headers: - `X-API-Key` — hex-encoded Ed25519 public key (64 chars). The public key *is* the API key. Obtain/register one via `POST /createApiKey`. - `X-Timestamp` — Unix time in **nanoseconds** as a decimal string (e.g. `"1713825891591000000"`). Millisecond or second epochs are rejected with `401 Unauthorized`. Must be within ±30,000 ms (`MaxTimestampDriftMs`, the drift window stays configured in milliseconds) of server wall-clock; otherwise the request is rejected with `401 Unauthorized`. - `X-Signature` — lowercase hex-encoded Ed25519 signature (128 chars). **Single-order endpoints** (`placeOrder`, `cancelOrder`, `modifyOrder`) use the **ordersign typed canonical payload** as the signing message — a compact, key-sorted JSON object with engine-native integer values. The payload is NOT the raw HTTP body; it is built from the parsed request fields: ``` placeOrder: {"ad":"0x…","ai":N,[,"c":"…"],"ct":N,"g":N,"m":N,"op":1,"p":N,"q":N,"r":0|1,"s":N,"t":N,"v":1} cancelOrder: {"ad":"0x…","ai":N,[,"c":"…"],"ct":N,[,"id":"…"],"m":N,"op":2,"v":1} modifyOrder: {"ad":"0x…","ai":N,[,"c":"…"],"ct":N,[,"id":"…"],"m":N,"op":3,"p":N,"q":N,"v":1} ``` `ct` in the payload must equal `X-Timestamp`. Integer values `p`, `q` etc. are engine-native ticks/quantums, not human-readable decimals. Keys in brackets are conditional (omitted when empty). `op` is the operation enum: `1`=place, `2`=cancel, `3`=modify, `4`=placeUntriggered (TPSL). See the `ordersign` package for full field definitions and reference signing code. **Batch endpoints do not use this header** — see below. - **Batch endpoints are signed per order — no `X-Signature`.** `POST /batchPlaceOrders` and `POST /batchCancelOrders` require `X-API-Key` + `X-Timestamp` only; the gateway does **not** verify an envelope `X-Signature` for these routes. Instead, each element of the `orders` / `cancels` array embeds its own `"signature"` field — a 128-hex Ed25519 signature over the **ordersign typed canonical payload** for that operation: - Plain `orders` elements (no `tpsl_type`) use `op=1`. - TPSL / conditional `orders` elements (with `tpsl_type`) use `op=4` (`OpPlaceUntriggered`) — same field set as `op=1` but a different `op` value, preventing replay of a TPSL signature as a plain placeOrder. - `cancels` elements use `op=2`. The `ct` field inside every element's payload must equal the shared `X-Timestamp` header value. The whole batch consumes a single replay slot. Read-only endpoints (`GET /openOrders`, `GET /fills`, etc.) require only `X-API-Key`. In relaxed local development the gateway may run with signatures disabled; the OpenAPI `security` blocks list `signedRequest` (the three-header AND) or `{}` (empty) to reflect that. ## Account-scoped requests Public account info reads such as fills, positions, orders, open orders, and account snapshots require `address` as a **query parameter**. Signed order management requests also require `address`, and it must match the master Ethereum address returned for that API key from `POST /createApiKey`. WebSocket `placeOrder` / `cancel` / `batchPlaceOrders` / `batchCancelOrders` / `modifyOrder` use the same value in the JSON payload field `address`. ## Order execution is asynchronous `POST /placeOrder`, `POST /cancelOrder`, `POST /batchPlaceOrders`, and `POST /batchCancelOrders` are asynchronous. They return either: - **`202 Accepted`** — the common case. The signed request was validated by the gateway and forwarded to the matching engine; the body does **not** carry the order's terminal state. - **`200 OK`** — returned only when the gateway already has definitive state for the request by the time it responds (the body's `status` reflects that state, e.g. `OPEN` / `FILLED` / `CANCELED` / `REJECTED`). Clients should treat this as best-effort enrichment and not rely on it. In both cases the body echoes `orderId` / `clientId` so callers can correlate WebSocket events with the request. To observe the full order lifecycle (`OPEN`, `FILLED`, `CANCELED`, `REJECTED`, fills, rejection reasons, etc.) clients **must** subscribe to the `orders` WebSocket channel (and `userFills` for trade-level events). Treat both the `202` and `200` HTTP bodies as request acknowledgements; all definitive state lives on the WebSocket. `POST /modifyOrder` and `POST /batchModifyOrders` are **not implemented yet** — the schemas are declared so consumers can wire against the final shape, but the gateway returns `501 Not Implemented` today. When live, they will follow the same async contract. ## Order rejection reasons When the matching engine (go-core) rejects an order, the resulting `AccountUpdate` event (delivered over the WebSocket `account` channel with `type: REJECTED`) carries a `rejectionReason` enum. The same value may also appear on HTTP `OrderResponse` / `CancelOrderResponse` bodies that resolved to definitive state before returning (the `200` path described above). The complete set of reasons go-core can emit today is: | Value | Meaning | |------------------------------|-------------------------------------------------------------------------| | `POST_ONLY_WOULD_CROSS` | Post-only order was rejected because it would have crossed the book and taken liquidity. | | `SELF_TRADE` | Order would have matched against another resting order belonging to the same account; self-trade prevention rejected it. | | `UNDERCOLLATERALIZED` | Account has insufficient free collateral / margin to support the order. | | `COULD_NOT_FILL` | Generic "could not fill" outcome. Legacy reason — prefer the IOC/FOK-specific values below for time-in-force-driven cancels. | | `IOC_CANCELED` | An `IMMEDIATE_OR_CANCEL` order produced zero fills against the book and was canceled. | | `FOK_FAILED` | A `FILL_OR_KILL` order could not be filled in full at submission and was canceled in its entirety. | | `REDUCE_ONLY_WOULD_INCREASE` | A `reduceOnly` order was rejected because executing it would have opened or increased the account's position rather than reducing it. | | `TOO_MANY_CLIENT_IDS` | Account already has 10,000 live `clientId`s (the per-account maximum). Cancel an existing order or wait for one to reach a terminal state to free a slot. | | `DUPLICATE_CLIENT_ID` | The `clientId` already maps to a live order on this account. Cancel the prior order (or use atomic modify via `placeAndCancel`) before reusing the same `clientId`. | See the `RejectionReason` schema for the canonical enum. ## Rate limiting Rate-limited endpoints return `429 Too Many Requests` carrying two retry-after signals: - `Retry-After` HTTP header (integer seconds, RFC 7231 compliant). - `retryAfterMs` field in the JSON body — precise milliseconds. The body also carries a typed `reason` indicating which layer rejected (`ip`, `account_empty`, `account_partial`). See `RateLimitedError` for the schema and `TooManyRequests` for the behavioral contract. Partner market-makers may be added to the bypass allowlist via the `RATELIMIT_BYPASS_ADDRESSES` server-side configuration (per environment). Allowlisted addresses skip rate-limit charging entirely and never receive a 429 from this layer. servers: - url: https://api.testnet.arcus.xyz description: Testnet - url: https://api.arcus.xyz description: Mainnet security: [] tags: - name: Onboarding description: Account and API key management. - name: Public description: >- Unauthenticated endpoints — market data, health checks, and account-scoped info reads. - name: Exchange description: > Signed order management endpoints (all are HTTP `POST`). Every request must carry the full header triple `X-API-Key` + `X-Timestamp` + `X-Signature` where `X-Signature` is an Ed25519 signature over the operation-specific signing message: `placeOrder`, `cancelOrder`, and `modifyOrder` sign the ordersign typed canonical payload (the JSON object itself, no prefix), while `cancelAllOrders` and `setLeverage` use the legacy `X-Timestamp + ACTION + canonicalJSON(body)` message (ACTION = the final camelCase path segment; the HTTP method is not signed). `X-Timestamp` is a Unix nanosecond epoch (decimal string) and must be within ±30,000 ms of server wall-clock. See the top-level **Authentication** section for full details. These endpoints also require query parameter `address` matching the key's master Ethereum address. - name: Referral description: > Affiliate / referral program endpoints. Mutating endpoints (`POST`) require the full Ed25519 signature triple and the body `address` must match the API key's master Ethereum address. Read endpoints (`GET`) are public and scoped by `?address=`. - name: Meta description: > Product / UX-level APIs served by the `api-meta` service. These live behind the same host as the rest of the API but are routed (via the ALB path rule on `/v1/api-meta/*`) to a separate deployment with its own ScyllaDB keyspace and its own deployment lifecycle. They share the same `X-API-Key` + Ed25519 signature scheme as Exchange endpoints; the signed `REQUEST_PATH` includes the `/v1/api-meta/...` prefix verbatim. - name: UserPreferences description: > Per-master-wallet preference store (favorited markets, dashboard layouts, theme, language, …). Reads are public and scoped by `?address=`; writes (PATCH / DELETE) require an Ed25519 signature and are bound to the address registered to `X-API-Key`. See `UserPreferenceKey` for the known keys and `UserPreferenceValue` for the type system. - name: MarketMetadata description: > Curated reference data for markets (company profile, branding, headline financials, …) refreshed from the upstream ticker feed. Reads are public; freshness is bounded by the per-row `ingestedAt` returned in the response envelope. - name: Notifications description: > Per-master-wallet inbox of "unseen events" surfaced from the matching engine: terminal resting-order fills (maker side, fully filled), liquidations, and TP/SL triggers. Reads are public and scoped by `?address=`; the `:markSeen` write requires an Ed25519 signature and is bound to the address registered to `X-API-Key`. Notifications expire after 30 days. paths: /v1/markets: get: tags: - Public summary: Get markets description: >- Returns all markets with details, sorted by ascending `marketId`. Optionally filter by market name. operationId: getMarkets parameters: - name: market in: query required: false schema: type: string enum: - BTC-USD - ETH-USD description: Optional market filter. examples: btc: value: BTC-USD responses: '200': description: Markets list. content: application/json: schema: $ref: '#/components/schemas/MarketsResponse' '400': description: Invalid market filter. content: application/json: schema: $ref: '#/components/schemas/error' '429': $ref: '#/components/responses/TooManyRequests' x-codeSamples: - lang: Shell label: curl source: | curl https://api.testnet.arcus.xyz/v1/markets curl "https://api.testnet.arcus.xyz/v1/markets?market=BTC-USD" - lang: Python label: requests source: | import requests r = requests.get( "https://api.testnet.arcus.xyz/v1/markets", params={"market": "BTC-USD"}, ) print(r.json()) - lang: TypeScript label: fetch source: | const url = new URL("https://api.testnet.arcus.xyz/v1/markets"); url.searchParams.set("market", "BTC-USD"); const res = await fetch(url); console.log(await res.json()); components: schemas: MarketsResponse: type: object required: - markets properties: markets: type: array description: One entry per market, sorted by ascending `marketId`. items: $ref: '#/components/schemas/MarketInfo' error: type: object required: - error properties: error: type: string description: Human-readable error message. examples: - Invalid request body code: type: string description: > Machine-readable error code for generic (non-order) rejections. Present on geo-restriction blocks; clients should key product-availability UI off this rather than the human `error` string. | Value | Meaning | |------------------|---------| | `GEO_RESTRICTED` | The action is not available from the caller's country/region for this product (perps and/or spot). Reads remain available; only state-changing actions are blocked. | enum: - GEO_RESTRICTED errorSource: type: string description: > Scopes the failure to a specific operation. Present on structured order errors (place / cancel / modify flows); absent on generic HTTP errors. enum: - Order - Cancel errorType: type: string description: > Machine-readable reason for the API-layer rejection. Present alongside `errorSource` on structured order errors; absent on generic HTTP errors. | Value | Meaning | |-------------------|---------| | `Tick` | Price or size does not align to the market's tick size / step size. | | `InvalidRequest` | A request field failed validation (bad address, unknown market, invalid enum, etc.). TPSL-specific causes: `stopPrice` required when `tpslType` is set; `tpslType` must be `STOP_LOSS` or `TAKE_PROFIT`; `reduceOnly` must be `true` for TPSL orders; trigger price must not sit on the wrong side of the current oracle (would fire immediately); batch grouping/shape constraints violated (wrong order count, missing or duplicate `tpslType` legs). | | `OracleDeviation` | The order's price deviates from the current oracle price by more than the allowed threshold. Adjust the price closer to the oracle and resubmit. | | `ReduceOnly` | A reduce-only order was rejected because filling it would open or increase the account's position rather than reduce it. | | `Unavailable` | The requested operation (place / cancel) is temporarily disabled. | | `Unauthorized` | API key or trading-identity check failed. | | `Forbidden` | The authenticated key is not permitted to perform the requested operation. | | `NotImplemented` | The requested capability is not yet available on this path (e.g. TPSL over WebSocket). | | `Transmission` | The gateway accepted and validated the request but could not deliver it to the matching engine. Retry. | | `Internal` | Unexpected gateway-side failure unrelated to transmission. | enum: - Tick - InvalidRequest - OracleDeviation - ReduceOnly - Unavailable - Unauthorized - Forbidden - NotImplemented - Transmission - Internal rejectionReason: type: string description: > Machine-readable engine-level rejection code. Present on `OrderResponse` / `BatchOrderItemResponse` when `status` is `REJECTED` on the synchronous `200` path (i.e. the gateway already had a definitive engine reject before responding). Absent on `202` responses and on HTTP error bodies — in those cases rejection reasons are delivered asynchronously via the `orders` WebSocket channel. Mirror of the canonical `RejectionReason` schema in `openapi.yaml` — keep the two in lockstep (and the hardcoded list in `sdks/python/scripts/post_process_models.py`). | Value | Meaning | |------------------------------------|---------| | `POST_ONLY_WOULD_CROSS` | Post-only order would have crossed the book and taken liquidity. | | `SELF_TRADE` | Order would match against the account's own resting order; blocked by self-trade prevention. | | `UNDERCOLLATERALIZED` | Account has insufficient free collateral / margin to support the order. | | `COULD_NOT_FILL` | Generic "could not fill" (legacy; prefer `IOC_CANCELED` / `FOK_FAILED`). | | `IOC_CANCELED` | IOC order produced zero fills and was canceled. | | `FOK_FAILED` | FOK order could not be fully filled at submission. | | `REDUCE_ONLY_WOULD_INCREASE` | reduce-only order would have opened or increased the position. | | `TOO_MANY_CLIENT_IDS` | Account already has 10,000 live `clientId`s (the per-account maximum). Cancel or let existing orders reach a terminal state to free slots before placing new ones with distinct `clientId`s. | | `DUPLICATE_CLIENT_ID` | Account already has an open order with the same `clientId`. | | `POSITION_TPSL_ALREADY_EXISTS` | A position-level TPSL of the same trigger class (TP or SL) already exists for this account+market. At most one TP and one SL per market. | | `ENTRY_TPSL_CANNOT_BE_POSITION_TPSL` | A TPSL bound to an entry order (`parentOrderId` set) cannot also be a position-level TPSL; entry-linked TPSLs are sized partial legs. | | `OPEN_ORDER_CAP_EXCEEDED` | Account has reached its per-account open-order cap; cancel a resting order or let one reach a terminal state before placing another. | | `ORDER_WILL_TAKE_LIQUIDITY_DURING_MARKET_HALT` | Outside regular trading hours, a crossing order would have taken liquidity past the off-hours trading bound while the market is halted at that band. | | `ORDER_NOT_FOUND` | `cancelOrder` referenced an order not on the orderbook (already filled, canceled, never placed, or owned by another account). | | `ORDER_NOT_FOUND_FOR_MODIFY` | `modifyOrder` referenced an order not on the regular orderbook; TPSL and untriggered orders cannot be modified. | | `MODIFY_CHANGED_IMMUTABLE_FIELD` | `modifyOrder` attempted to change an immutable field (`side`, `timeInForce`, `reduceOnly`, or `orderType`). | | `MODIFY_ZERO_SIZE` | `modifyOrder` specified a new size of zero or less. | enum: - POST_ONLY_WOULD_CROSS - SELF_TRADE - UNDERCOLLATERALIZED - COULD_NOT_FILL - IOC_CANCELED - FOK_FAILED - REDUCE_ONLY_WOULD_INCREASE - TOO_MANY_CLIENT_IDS - DUPLICATE_CLIENT_ID - POSITION_TPSL_ALREADY_EXISTS - ENTRY_TPSL_CANNOT_BE_POSITION_TPSL - OPEN_ORDER_CAP_EXCEEDED - ORDER_WILL_TAKE_LIQUIDITY_DURING_MARKET_HALT - ORDER_NOT_FOUND - ORDER_NOT_FOUND_FOR_MODIFY - MODIFY_CHANGED_IMMUTABLE_FIELD - MODIFY_ZERO_SIZE MarketInfo: type: object required: - marketDisplayName - marketId - status - baseAsset - quoteAsset - tickSize - stepSize - tickTiers - minOrderNotional - type - category - addedTimestamp properties: marketDisplayName: $ref: '#/components/schemas/MarketDisplayName' fullAssetName: type: string description: >- Human-readable name of the underlying asset. Omitted when no canonical name is configured for the market. examples: - Bitcoin marketId: $ref: '#/components/schemas/MarketId' status: type: string description: >- Operational state of the market. `OFFLINE` markets are returned for visibility but should not be quoted or traded. examples: - ONLINE - OFFLINE baseAsset: type: string examples: - BTC quoteAsset: type: string examples: - USD tickSize: type: string stepSize: type: string tickTiers: type: array description: > Per-price-band placement grid: a submitted limit price must be a multiple of the `tick` for the band its price falls in. Bands are ascending by `upToPrice` (the last band is unbounded — `upToPrice` omitted). `tickSize` equals the base tier, so clients that read only `tickSize` stay correct for prices in the base band. items: type: object required: - tick properties: upToPrice: type: string description: >- Exclusive upper price bound (decimal USD) for this band; omitted for the unbounded top band. tick: type: string description: Minimum price increment (decimal USD) for prices in this band. minOrderNotional: type: string description: > Flat minimum order notional (`quantity` × `price`, decimal USD) on position-opening orders. Reduce-only orders (including TPSLs) are exempt. examples: - '5' oraclePrice: type: string description: >- Latest oracle price as a decimal USD string. "0" if no update has been received yet. markPrice: type: string description: > Authoritative mark price stamped by go-core, as a decimal USD string. "0" means no mark price has been received yet — callers must not fall back to `oraclePrice` in that case. Currently equals `oraclePrice`; will be replaced by the 2.5-min EWMA of impact-mid minus oracle once that feed is wired in. fundingRate: type: string description: > Most recently applied funding rate — always the rate the engine actually charged at the last tick, never a recomputation. Funding keeps ticking hourly while a market is outside its `regularTradingHours` window, with each off-hours tick pinned to the fixed financing rate (SOFR + 0.5% annualized, expressed per hour), so this converges to the off-hours rate within one funding interval of a close. nextFundingRate: type: string description: > Forecast for the next funding rate. In regular trading hours (and for 24/7 markets) this is the funder's in-progress order-book forecast; while the market is outside RTH (`isOutsideRth` is `true`) it is the fixed off-hours financing rate (SOFR + 0.5% annualized, per hour) the engine will pin the next tick to. nextFundingAt: type: integer format: int64 description: Unix seconds for the next funding payment time. priceChange24h: type: string volume24h: type: string volume24hNotional: type: string trades24h: type: integer format: int64 openInterest: type: string description: >- Open interest: total size of all open long positions in the market (equals total short), in base asset units. Refreshed periodically from a snapshot, so it may lag real time by up to the poll interval. initialMarginFraction: type: string maintenanceMarginFraction: type: string offHoursInitialMarginFraction: type: string description: > Initial margin fraction the engine enforces when the market is outside its `regularTradingHours` window (overnight and weekends for equity-class markets), reflecting gap risk while the venue is closed. Equals `initialMarginFraction` for 24/7 markets (crypto). Size buying power against this whenever `regularTradingHours` is present and the current time falls outside that window — otherwise an order sized at the in-RTH leverage will be rejected `UNDERCOLLATERALIZED`. Maintenance margin is not uplifted off-hours. regularTradingHours: $ref: '#/components/schemas/RegularTradingHours' isOutsideRth: type: boolean description: > Off-hours flag for markets that have a `regularTradingHours` window, sourced from the exchange calendar (weekends and US holidays included) rather than derived client-side. When `true`, `nextFundingRate` carries the fixed off-hours rate (SOFR + 0.5%). Omitted for 24/7 markets (crypto), and omitted briefly while the server has not yet learned the market's state (e.g. right after a deploy): `regularTradingHours` present with `isOutsideRth` absent means the state is not yet known. currentSettlementPrice: type: string description: > Sealed VWAP settlement price (decimal USD) that anchors the off-hours trading band, sealed by the engine when the market exits its `regularTradingHours` window. Present only while the market is outside RTH with a sealed anchor; omitted in-RTH and for 24/7 markets (crypto), which have no settlement anchor. currentTradingBound: type: string description: > Off-hours trading-band multiplier currently in force, as a decimal string (`"0.5"`, `"1"`, `"2"`, `"4"`). The band widens around the settlement anchor as `anchor ± anchor × initialMarginFraction × bound`. A freshly opened off-hours session reports `"0.5"` before any bound event. Present only while the market is outside RTH with a sealed anchor; omitted in-RTH and for 24/7 markets. nextTradingBound: type: string description: > The next wider off-hours trading-band multiplier the market can expand to, one level above `currentTradingBound` on the fixed `0.5` → `1` → `2` → `4` ladder, as a decimal string. Always differs from `currentTradingBound` except at the `"4"` maximum (where there is no wider band, so it equals `currentTradingBound`). Present only while the market is outside RTH with a sealed anchor; omitted in-RTH and for 24/7 markets. type: $ref: '#/components/schemas/MarketType' category: $ref: '#/components/schemas/MarketCategory' addedTimestamp: type: integer format: int64 description: Unix seconds at which this market was first listed. assetResolution: type: string description: >- Integer scaling factor used for on-wire quantum math (e.g. `"10000000000"` for 1e-10 base units). pythId: type: string description: >- Pyth Network price feed id for this market's index/oracle pair — numeric string for Pyth Pro, 0x-prefixed hex for legacy Hermes (e.g. `"1"` for Crypto.BTC/USD on Pyth Pro). RateLimitedError: description: > 429 response body shape. Extends the generic `Error` with two rate-limit-specific fields: - `reason` — which limiter rejected the request. Stable string enum; new values may be added in future versions, so clients should treat unknown values as opaque. - `retryAfterMs` — precise milliseconds the client should wait before retrying. The HTTP `Retry-After` header carries the same information rounded up to whole seconds (RFC 7231); prefer this field when sub-second precision matters. type: object required: - error properties: error: type: string example: rate limited reason: type: string enum: - ip - account_empty - account_partial - unknown description: | Layer that rejected the request: * `ip` — per-IP weight bucket exhausted. * `account_empty` — per-subaccount pool fully exhausted; the drip-throttle has no token available either. * `account_partial` — pool has some credit but not enough for this batch. Split the request into smaller chunks to drain the remaining headroom. * `unknown` — defensive fallback; clients should retry per `retryAfterMs` and report the occurrence. retryAfterMs: type: integer format: int64 minimum: 0 description: >- Milliseconds to wait before retrying. Matches the precise wait the rate limiter computed (the `Retry-After` header rounds up to the next whole second). clientId: type: string description: > Echo of the request's client-supplied `clientId`, so the client can correlate the rejection to a specific order request. Present only on single-order endpoints (placeOrder, modifyOrder, cancelOrder) when the request carried a `clientId`. Omitted on batch endpoints (see `clientIds`) and when the request had none. clientIds: type: array items: type: string description: > Echo of every client-supplied `clientId` in a batch request (batchPlaceOrders, batchCancelOrders), positionally aligned with the submitted `orders` / `cancels` array. A batch is rejected all-or-nothing, so every listed order was rejected; the echo lets a client submitting multiple batches concurrently correlate the 429 to a specific batch. An entry is empty when that element carried no `clientId` (e.g. a cancel-by-orderId). Omitted on single-order endpoints (see `clientId`). MarketDisplayName: type: string description: Market symbol (e.g. BTC-USD). examples: - BTC-USD MarketId: type: integer minimum: 0 maximum: 65535 description: >- Perpetual market identifier (uint16). Map to display name via `GET /markets`. Used for orders, positions, funding, and market metadata. RegularTradingHours: type: object description: > Market session window during which the base margin fractions (`initialMarginFraction` / `maintenanceMarginFraction`) apply. Outside this window the `offHours*` fractions apply. Times are local seconds-of-day in [0, 86400) in `timezone`. Weekend and holiday closures are venue-calendar concerns layered on top and are NOT encoded here, so a client deriving the current session must also exclude those. Omitted entirely for 24/7 markets (crypto). required: - startSecondsOfDay - endSecondsOfDay - timezone - isOvernight properties: startSecondsOfDay: type: integer format: int32 description: >- Local seconds-of-day at which the session opens (e.g. `14400` = 04:00). endSecondsOfDay: type: integer format: int32 description: >- Local seconds-of-day at which the session closes. Half-open — a time exactly at the close is outside RTH. timezone: type: string description: IANA timezone the seconds-of-day are expressed in. examples: - America/New_York isOvernight: type: boolean description: >- True when the window wraps past local midnight (`startSecondsOfDay` > `endSecondsOfDay`), e.g. an 18:00→17:00 session. MarketType: type: string enum: - PERPETUAL - SPOT description: Kind of market venue exposed for a symbol. MarketCategory: type: string enum: - CRYPTO - INDICES - EQUITIES - FOREX - COMMODITIES description: Underlying asset class of a market. responses: TooManyRequests: description: > Rate limit exceeded. Two signals are returned, designed to coexist with both naive HTTP clients and rate-limit-aware SDK clients: - `Retry-After` header (integer seconds, RFC 7231 compliant). Rounds up — clients that obey this header sleep at least as long as required. Safe for generic HTTP libraries to read. - JSON body `retryAfterMs` (precise milliseconds, matches the server's internal computation). Sophisticated clients should prefer this over the header to avoid the round-up overshoot. - JSON body `reason` indicates which rate-limit layer rejected: `ip` (per-IP weight bucket), `account_empty` (per-subaccount pool fully exhausted, in drip throttle), `account_partial` (pool has some credit but not enough for this batch — split the request smaller to drain), or `unknown` (defensive fallback). - JSON body `clientId` (single-order endpoints) or `clientIds` (batch endpoints) echoes the request's client-supplied order identifier(s) so the client can correlate the rejection to a specific order request. Allowlisted addresses bypass the rate-limit middleware entirely (see `RATELIMIT_BYPASS_ADDRESSES`); they never receive a 429 from this layer. headers: Retry-After: $ref: '#/components/headers/RetryAfter' content: application/json: schema: $ref: '#/components/schemas/RateLimitedError' example: error: rate limited reason: account_empty retryAfterMs: 850 clientId: my-order-42 headers: RetryAfter: description: Seconds the client should wait before retrying the request. schema: type: integer minimum: 1 example: 1 ````