> ## Documentation Index > Fetch the complete documentation index at: https://docs.calibri.io/llms.txt > Use this file to discover all available pages before exploring further. # Place a signed order > Places a non-custodial order. `signed_order` is an EIP-712 signature over the CTF Exchange Order struct. Atlas validates it — a signature it cannot verify is rejected rather than placed — then relays to the engine and attaches the signature. Placing locks the stake PLUS the maximum taker fee the fill could incur; the unused reserve is released. PASSKEY WALLETS: a passkey signs only in the browser it was registered in, and browser-held session keys are non-extractable, so neither can sign from a script. To place orders programmatically, add a SECOND SIGNING KEY to your wallet (Settings → Wallet → Signing keys) — an address you hold the key for, which becomes an owner of the same Safe. Orders stay `signature_type` 3 with maker == signer == the Safe; the signature becomes a standard Safe owner signature over the EIP-712 `SafeMessage(bytes message)` whose message is `abi.encode(orderHash)`, in a domain of (chainId, the Safe). Signing the order hash directly always fails. MARKET ORDERS AND EXPIRY: a market-style order is a limit at a price ceiling; send `ioc: true` and the unfilled remainder is refunded rather than rested. The signature's `expiration` is enforced by the engine — it never matches an order within 30 seconds of its expiry (a fill must settle on-chain before the signature lapses), cancels and refunds a resting order at that point, and rejects an order that arrives inside that window (`market.order.expired`). ## OpenAPI ````yaml /api-reference/openapi/calibri.yaml post /api/v2/atlas/account/orders openapi: 3.1.0 info: title: Calibri API version: 1.0.0 description: >- The Calibri API. Discover markets, read live books, place signed orders, and manage positions and account data. Routed by path prefix to the service that answers it — which is an implementation detail, not something a caller has to reason about. servers: - description: Production url: https://calibri.io security: [] tags: - name: Health description: Service liveness. x-displayName: Health - name: Events description: Discover events and their metadata. x-displayName: Events - name: Markets description: List markets and load market detail for trading. x-displayName: Markets - name: Series description: Recurring event series. x-displayName: Series - name: Tags description: Editorial shelves used to browse the catalogue. x-displayName: Tags - name: Market Data description: Order book, depth, trade tape, tickers, and candles. x-displayName: Market Data - name: Assets description: Underlying asset price history for price-feed markets. x-displayName: Assets - name: Community description: Leaderboard and platform activity. x-displayName: Community - name: Currencies description: Currency registry. x-displayName: Currencies - name: Trade description: Place, list, and cancel orders. x-displayName: Trade - name: Positions description: Your matched contracts. x-displayName: Positions - name: Wallet description: Self-custody Safe, passkey, session keys, and relay. x-displayName: Wallet - name: Rewards description: Maker rebates and referral earnings. x-displayName: Rewards - name: Account description: Balances, ledger, PnL, limits, preferences, and profile. x-displayName: Account - name: Categories description: Categories x-displayName: Categories - name: Other description: Other x-displayName: Other externalDocs: description: '' url: '' paths: /api/v2/atlas/account/orders: post: tags: - Trade summary: Place a signed order description: >- Places a non-custodial order. `signed_order` is an EIP-712 signature over the CTF Exchange Order struct. Atlas validates it — a signature it cannot verify is rejected rather than placed — then relays to the engine and attaches the signature. Placing locks the stake PLUS the maximum taker fee the fill could incur; the unused reserve is released. PASSKEY WALLETS: a passkey signs only in the browser it was registered in, and browser-held session keys are non-extractable, so neither can sign from a script. To place orders programmatically, add a SECOND SIGNING KEY to your wallet (Settings → Wallet → Signing keys) — an address you hold the key for, which becomes an owner of the same Safe. Orders stay `signature_type` 3 with maker == signer == the Safe; the signature becomes a standard Safe owner signature over the EIP-712 `SafeMessage(bytes message)` whose message is `abi.encode(orderHash)`, in a domain of (chainId, the Safe). Signing the order hash directly always fails. MARKET ORDERS AND EXPIRY: a market-style order is a limit at a price ceiling; send `ioc: true` and the unfilled remainder is refunded rather than rested. The signature's `expiration` is enforced by the engine — it never matches an order within 30 seconds of its expiry (a fill must settle on-chain before the signature lapses), cancels and refunds a resting order at that point, and rejects an order that arrives inside that window (`market.order.expired`). parameters: [] requestBody: content: application/json: schema: $ref: '#/components/schemas/CreateOrderRequest' responses: '201': content: application/json: schema: $ref: '#/components/schemas/OrderEntity' description: '' '422': content: application/json: schema: $ref: '#/components/schemas/ErrorEntity' description: Signature or validation failure security: - apiKey: [] components: schemas: CreateOrderRequest: properties: direction: description: >- Whether you are opening or closing. `buy` posts collateral and acquires the outcome; `sell` offers outcome tokens you already hold, so it locks INVENTORY rather than cash and its `locked` is zero. Defaults to `buy`, which is how every order behaved before position exit. See /account/positions for how much of a holding is sellable. enum: - buy - sell example: buy type: string ioc: description: >- Immediate-or-cancel. Set it on a marketable order — the "market" order a signed wallet has to send as a limit at a price ceiling: whatever the book cannot fill on arrival is refunded instead of resting at that ceiling. Ignored together with `post_only`. Recorded on the order as `ioc`. example: false type: boolean market: description: Market id. example: '12' type: string ord_type: enum: - limit - market example: limit type: string post_only: description: >- Reject the order if it would take liquidity. A post-only order reserves no taker fee, because it can only ever rest as a maker. example: false type: boolean price: description: >- Limit price, `0.01`–`0.99`, in whole cents (e.g. 0.27, not 0.275) — an order finer than the market precision is rejected, not rounded. Required for a limit order. example: '0.60' type: string side: description: >- The OUTCOME this order is about — never buy/sell. Pair it with `direction`: a sell of `yes` and a buy of `no` are different orders that happen to sit on the same side of the book. enum: - 'yes' - 'no' example: 'yes' type: string signed_order: $ref: '#/components/schemas/SignedOrderEntity' description: >- The EIP-712-signed order. Validated before anything is placed — a signature the server cannot verify is rejected, never rested. volume: description: Number of shares. example: '100' type: string required: - market - side - ord_type - volume - signed_order type: object OrderEntity: properties: contracts_count: description: Contracts formed from this order. example: 1 type: number created_at: example: '2026-08-07T10:00:00Z' type: string filled_volume: example: '60' type: string id: example: usdc type: number locked: description: >- Collateral locked. A separate taker-fee reserve is held alongside it and released when unused. example: '61.68' type: string market: description: Market id. example: '12' type: string ord_type: enum: - limit - market example: limit type: string origin_volume: example: '100' type: string price: description: >- Limit price, `0.01`–`0.99`, in whole cents (e.g. 0.27, not 0.275) — finer than the market precision is rejected, not rounded. example: '0.60' type: string remaining_volume: description: Unmatched remainder. example: '40' type: string side: enum: - 'yes' - 'no' example: 'yes' type: string state: enum: - pending - wait - done - cancel - reject example: active type: string updated_at: example: '2026-08-07T10:05:00Z' type: string required: - id - market - side - ord_type - state - origin_volume - remaining_volume - locked - contracts_count - created_at - updated_at type: object ErrorEntity: properties: errors: description: Match on the code, not the HTTP status or the human text. example: - account.custody.deposits_disabled items: type: string type: array required: - errors type: object SignedOrderEntity: properties: expiration: description: Unix seconds. Must be non-zero, unexpired, and within 365 days. example: '1797600000' type: string fee_rate_bps: description: >- Must be `"0"`. The taker fee is collected separately on-chain from your Safe, not through this field. example: '0' type: string maker: description: >- Your Safe — the address the collateral comes from. For signature type 3 this equals `signer`. example: '0x0DECE7d83f8D47CD8dD8278c0F22c361C58577BD' type: string maker_amount: description: USDC in, 6-decimal base units. `round(price × volume × 1e6)`. example: '60000000' type: string nonce: description: Exchange nonce. example: '0' type: string salt: description: >- Random per-order value. Two orders with identical terms must not share one. example: '5821094412' type: string side: description: >- Always `0` (BUY). Both YES and NO legs are buys that mint — the side you are taking is carried by `token_id` alone. enum: - 0 example: 0 type: number signature: description: >- The EIP-712 signature. For a session-signed order this is `abi.encode(keyId, r, s)` — exactly 96 bytes — which is how the server tells a session key from a passkey. example: 0x4f2a… type: string signature_type: description: >- `2` POLY_GNOSIS_SAFE (your Safe, owned by your wallet) or `3` POLY_1271 (your Safe, owned by a passkey). Read it from `signature_type` on the wallet config rather than choosing one — an order signed the way the other type requires is rejected. enum: - 2 - 3 example: 2 type: number signer: description: >- Whoever signed. Your wallet EOA for types 0 and 2; the Safe itself for type 3, where a passkey or session key produced the signature. example: '0xE1188438C85C98aADFf1a88f97764E607B4978C3' type: string taker: description: The zero address — the order is public and anyone may match it. example: '0x0000000000000000000000000000000000000000' type: string taker_amount: description: Outcome tokens out, 6-decimal. `round(volume × 1e6)`. example: '100000000' type: string token_id: description: >- The ERC-1155 position id for YOUR side. This is what says which market and which outcome — a signed order carries no market field. example: 7138104... type: string required: - salt - maker - signer - taker - token_id - maker_amount - taker_amount - expiration - nonce - fee_rate_bps - side - signature_type - signature type: object securitySchemes: apiKey: description: >- HMAC-signed API key. Send X-Auth-Apikey, X-Auth-Nonce and X-Auth-Signature. in: header name: X-Auth-Apikey type: apiKey ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.