> ## Documentation Index > Fetch the complete documentation index at: https://platform.trendlinelabs.ai/llms.txt > Use this file to discover all available pages before exploring further. # Place a limit order > Beta: not yet enabled; the launch venues are Polymarket, predict.fun and Limitless (Kalshi comes later). Requests answer 404 with {"detail": "Not Found"}, as an unregistered path does, until trading is switched on. Place one limit order with your own connected venue account, on a venue enabled for trading. Every order gets our `id` (ord_...) the moment we accept it. Send a client_order_id you generate; resending the same request with it never places a second order (the latest answer is replayed with Idempotent-Replay: true). 201: the venue accepted it. 202 status unknown: the venue's answer was not received; retry the SAME request (same client_order_id) or read GET /public/v1/orders/{id}, and it is reconciled from the venue, never re-submitted; where the venue cannot prove an order's absence the answer can stay unknown, so check the venue's own listing before trading the same intent again. 200: an answer a reconcile produced (the venue's state, or status not_placed). price is the price of `outcome`, 0..1 on the venue's grid, refused (never rounded) when off it. Refusals: 503 trading_halted; 403 trade_not_granted, jurisdiction_refused, trading_tier_required; 422 venue_unsupported, price_off_tick, limit_exceeded, venue_rejected, invalid_request; 404 not_found, venue_not_listed, venue_not_connected; 410 market_closed; 409 venue_leg_unverified, idempotency_conflict, request_in_progress (Retry-After), venue_auth_failed; 429 rate_limited; 503 venue_unavailable, dependency_unavailable. ## OpenAPI ````yaml /openapi.json post /public/v1/orders openapi: 3.1.0 info: description: >- Prediction-market data across Polymarket, Kalshi, Limitless and predict.fun over REST, and (Beta) order placement. Every request sends your key as `Authorization: Bearer tl_live_…`; try any endpoint from its page. title: TrendlineLabs Public API version: '1' servers: - description: Production url: https://systems.trendlinelabs.ai security: [] tags: - description: 'Read back the key you are calling with: its scopes, tier and rate limit.' name: Your key - description: Events group markets across venues; each carries a `universal_id`. name: Events - description: One market's order book, price history and trades on one venue. name: Markets - description: Current prices for a set of markets in one call. name: Prices - description: Live cross-venue price gaps on the same market. name: Opportunities - description: >- Beta, not yet enabled: place and cancel limit orders on your own venue accounts. name: Trading paths: /public/v1/orders: post: tags: - Trading summary: Place a limit order description: >- Beta: not yet enabled; the launch venues are Polymarket, predict.fun and Limitless (Kalshi comes later). Requests answer 404 with {"detail": "Not Found"}, as an unregistered path does, until trading is switched on. Place one limit order with your own connected venue account, on a venue enabled for trading. Every order gets our `id` (ord_...) the moment we accept it. Send a client_order_id you generate; resending the same request with it never places a second order (the latest answer is replayed with Idempotent-Replay: true). 201: the venue accepted it. 202 status unknown: the venue's answer was not received; retry the SAME request (same client_order_id) or read GET /public/v1/orders/{id}, and it is reconciled from the venue, never re-submitted; where the venue cannot prove an order's absence the answer can stay unknown, so check the venue's own listing before trading the same intent again. 200: an answer a reconcile produced (the venue's state, or status not_placed). price is the price of `outcome`, 0..1 on the venue's grid, refused (never rounded) when off it. Refusals: 503 trading_halted; 403 trade_not_granted, jurisdiction_refused, trading_tier_required; 422 venue_unsupported, price_off_tick, limit_exceeded, venue_rejected, invalid_request; 404 not_found, venue_not_listed, venue_not_connected; 410 market_closed; 409 venue_leg_unverified, idempotency_conflict, request_in_progress (Retry-After), venue_auth_failed; 429 rate_limited; 503 venue_unavailable, dependency_unavailable. operationId: placeOrder requestBody: content: application/json: schema: $ref: '#/components/schemas/PublicOrderRequest' required: true responses: '200': content: application/json: example: avg_price: null client_order_id: s1-0001 created_at: '2026-10-06T05:59:59+00:00' filled_size: '0' id: ord_6702291f8e1c2a0012ab34cd notional_reserved: '4.20' outcome: 'yes' price: '0.42' remaining_size: '10' side: buy size: 10 status: open time_in_force: gtc type: limit universal_id: mk-btc-100k-2026 updated_at: '2026-10-06T05:59:59+00:00' venue: polymarket venue_market_id: bitcoin-above-100k-on-december-31 venue_market_title: Bitcoin above $100,000 on December 31? venue_order_id: >- 0x5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e5e schema: $ref: '#/components/schemas/PublicOrder' description: >- a reconcile's answer (the venue's state, or not_placed), or a replay of the latest answer for this client_order_id headers: Cache-Control: description: no-store on every answer schema: type: string Idempotent-Replay: description: true on a replay schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '201': content: application/json: schema: $ref: '#/components/schemas/PublicOrder' description: the venue accepted the order (its first answer) headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '202': content: application/json: schema: $ref: '#/components/schemas/PublicOrder' description: >- status unknown: the venue's answer was not received; retry the same request, or read the order by its id headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '401': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: 'unauthorized: no key, or a key that is unknown, revoked or expired.' headers: Cache-Control: description: no-store on every answer schema: type: string WWW-Authenticate: description: Bearer realm="public-api" schema: type: string X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '403': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- insufficient_scope: the key lacks the scope this route needs; ip_not_allowed: the request came from an address outside the key's allowlist; tier_required: the key owner's plan does not include API access; access_not_granted: API access is free but granted on request; request it on https://trendlinelabs.ai/developer; trade_not_granted: the account holds no active trade grant; jurisdiction_refused: the jurisdiction recorded on your trade grant may not trade on that venue; trading_tier_required: the account's plan may not trade on that venue. headers: Cache-Control: description: no-store on every answer schema: type: string X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '404': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- not_found: no such event, market or key; venue_not_listed: the market has no leg on that venue; venue_not_connected: we hold no usable account of yours for that venue: not connected, held by another account, or (Limitless positions) an empty answer for a profile not verified as your sub-account (found only through its public profile); the message names the reason; order_not_found: no order with that id was placed through the API by this account. headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '409': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- idempotency_conflict: the client_order_id was already used with a different request; request_in_progress: a request with this client_order_id is still in flight; retry after Retry-After; venue_leg_unverified: the market's leg is not the venue market you named, or could not be verified; nothing was sent; venue_auth_failed: the venue refused your own stored credential; reconnect it; order_not_cancellable: the order is no longer open, the venue no longer holds it, or another credential placed it. headers: Cache-Control: description: no-store on every answer schema: type: string Retry-After: description: seconds to wait before retrying schema: type: integer X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '410': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: 'market_closed: the market''s leg on that venue no longer trades.' headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '422': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- invalid_request: a parameter is missing, unknown, malformed or out of bounds, or a cursor does not match; venue_unsupported: the route does not serve that venue; price_off_tick: the price is not on the venue's price grid; it is refused, never rounded; limit_exceeded: the order's maximum loss is over the per-order or daily limit, or no limit is set (limit_unset); venue_rejected: the venue rejected the order; the message carries the venue's own error code only. headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '429': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- rate_limited: too many requests, or too many failed authentications; wait Retry-After seconds. headers: Cache-Control: description: no-store on every answer schema: type: string Retry-After: description: seconds to wait before retrying schema: type: integer X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '500': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- internal_error: an unexpected failure on our side; quote the request id. The body may instead be text/plain with no envelope and no X-RateLimit-* headers when a failure escapes the route's own handling. headers: Cache-Control: description: no-store on every answer schema: type: string X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string '503': content: application/json: schema: $ref: '#/components/schemas/PublicError' description: >- dependency_unavailable: one of our own stores could not be read; retry later; trading_halted: new orders are halted for everyone; cancels, replays and reconciles still answer; venue_unavailable: the venue could not be read; the message names why; retry after Retry-After. headers: Cache-Control: description: no-store on every answer schema: type: string Retry-After: description: seconds to wait before retrying schema: type: integer X-RateLimit-Limit: description: >- requests allowed per window for this key; present once the key passed the limiter schema: type: integer X-RateLimit-Remaining: description: >- requests left in this window; present once the key passed the limiter schema: type: integer X-RateLimit-Reset: description: >- seconds until the window resets; present once the key passed the limiter schema: type: integer X-Request-Id: description: >- this request's id (yours, when you sent X-Request-Id); equals the envelope's request_id schema: type: string security: - HTTPBearer: [] x-codeSamples: - label: cURL lang: bash source: > #!/bin/sh # placeOrder: Place a limit order. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base. curl -sS -X POST "${TRENDLINE_API_BASE:-https://systems.trendlinelabs.ai}/public/v1/orders" \ -H "Authorization: Bearer $TRENDLINE_API_KEY" \ -H "Content-Type: application/json" -d '{"venue":"polymarket","universal_id":"mk-btc-100k-2026","outcome":"yes","side":"buy","type":"limit","price":"0.42","size":10,"client_order_id":"s1-0001"}' - label: Python lang: python source: > """placeOrder: Place a limit order. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.""" import os import requests BASE = os.environ.get("TRENDLINE_API_BASE", "https://systems.trendlinelabs.ai") KEY = os.environ["TRENDLINE_API_KEY"] r = requests.post(f"{BASE}/public/v1/orders", json={"venue": "polymarket", "universal_id": "mk-btc-100k-2026", "outcome": "yes", "side": "buy", "type": "limit", "price": "0.42", "size": 10, "client_order_id": "s1-0001"}, headers={"Authorization": f"Bearer {KEY}"}, timeout=10) print(r.status_code, r.json()) - label: JavaScript lang: javascript source: > // placeOrder: Place a limit order. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base. const BASE = process.env.TRENDLINE_API_BASE ?? "https://systems.trendlinelabs.ai"; const KEY = process.env.TRENDLINE_API_KEY; const r = await fetch(`${BASE}/public/v1/orders`, { method: "POST", headers: { Authorization: `Bearer ${KEY}`, "Content-Type": "application/json" }, body: JSON.stringify({"venue":"polymarket","universal_id":"mk-btc-100k-2026","outcome":"yes","side":"buy","type":"limit","price":"0.42","size":10,"client_order_id":"s1-0001"}) }); console.log(r.status, await r.json()); components: schemas: PublicOrderRequest: additionalProperties: false properties: client_order_id: description: >- an id you choose for this order (e.g. a UUID), unique per order; resend the same one only to retry the same order, which never places a second order pattern: ^[A-Za-z0-9_-]{1,64}$ title: Client Order Id type: string outcome: description: the venue's own outcome label the order is on enum: - 'yes' - 'no' title: Outcome type: string price: description: >- the limit price of `outcome`, a plain decimal string; a price off the venue's grid is refused, never rounded maxLength: 32 minLength: 1 pattern: ^[0-9]+(\.[0-9]+)?$ title: Price type: string side: description: buy or sell, the action on `outcome` at `price` enum: - buy - sell title: Side type: string size: description: whole contracts maximum: 1000000 minimum: 1 title: Size type: integer time_in_force: default: gtc description: >- gtc rests until cancelled, ioc fills what it can now and cancels the rest enum: - gtc - ioc title: Time In Force type: string type: const: limit description: the order type; only limit title: Type type: string universal_id: anyOf: - maxLength: 256 minLength: 1 type: string - type: 'null' description: >- the market universal id; its leg on `venue` is traded, so switching venue is one field. Send this, venue_market_id, or both title: Universal Id venue: description: >- the venue to trade on; only venues enabled for trading are accepted (no best-venue routing) enum: - kalshi - polymarket - limitless - predictfun title: Venue type: string venue_market_id: anyOf: - maxLength: 256 minLength: 1 type: string - type: 'null' description: >- the venue's own market id (on Kalshi, its ticker); with universal_id both must name the same leg, else 422, never re-routed title: Venue Market Id required: - venue - outcome - side - type - price - size - client_order_id title: PublicOrderRequest type: object PublicOrder: properties: avg_price: anyOf: - type: string - type: 'null' description: >- the average fill price of `outcome`, 0..1 as a decimal string, when the venue reported one title: Avg Price client_order_id: description: your id for this order title: Client Order Id type: string created_at: description: when we accepted the order, ISO 8601 title: Created At type: string filled_size: anyOf: - type: string - type: 'null' description: >- contracts filled, an exact decimal string; null while the status is unknown title: Filled Size id: description: >- our id for the order, ord_ and 24 hex digits; it exists from the moment we accept the request, so an order whose status is unknown has one too pattern: ^ord_[0-9a-f]{24}$ title: Id type: string notional_reserved: description: >- the order's maximum loss counted against your limits, USD as a decimal string title: Notional Reserved type: string outcome: description: the venue's own outcome label title: Outcome type: string price: description: the limit price of `outcome`, a decimal string title: Price type: string remaining_size: anyOf: - type: string - type: 'null' description: >- contracts still resting, an exact decimal string; null while the status is unknown title: Remaining Size side: description: buy or sell, the action on `outcome` at `price` enum: - buy - sell title: Side type: string size: description: whole contracts ordered title: Size type: integer status: description: >- unknown: the venue's answer was not received; retry with the same client_order_id or read GET /public/v1/orders/{id}, never send a new id. On a venue that cannot prove an order's absence it may stay unknown: check the venue before trading the same intent again enum: - open - filled - partially_filled - cancelled - unknown - not_placed title: Status type: string time_in_force: description: as requested enum: - gtc - ioc title: Time In Force type: string type: const: limit description: the order type; only limit title: Type type: string universal_id: anyOf: - type: string - type: 'null' description: >- the market universal id holding the leg; null when no market lists it title: Universal Id updated_at: description: when we last recorded a change to the order, ISO 8601 title: Updated At type: string venue: description: the venue the order was sent to enum: - kalshi - polymarket - limitless - predictfun title: Venue type: string venue_market_id: description: the venue's own market id the order went to title: Venue Market Id type: string venue_market_title: anyOf: - type: string - type: 'null' description: the leg's title on the venue, when our mirror holds it title: Venue Market Title venue_order_id: anyOf: - type: string - type: 'null' description: >- the venue's order id; null while the status is unknown and for an order that was never placed title: Venue Order Id required: - id - client_order_id - venue - universal_id - venue_market_id - outcome - side - type - price - size - time_in_force - status - notional_reserved - created_at - updated_at title: PublicOrder type: object PublicError: properties: error: $ref: '#/components/schemas/PublicErrorBody' description: the refusal required: - error title: PublicError type: object PublicErrorBody: properties: code: description: >- a machine-readable code from x-known-codes; a new code may be added, so handle an unknown one by its status title: Code type: string x-known-codes: - access_not_granted - dependency_unavailable - idempotency_conflict - insufficient_scope - internal_error - invalid_request - ip_not_allowed - jurisdiction_refused - limit_exceeded - market_closed - not_found - order_not_cancellable - order_not_found - price_off_tick - rate_limited - request_in_progress - tier_required - trade_not_granted - trading_halted - trading_tier_required - unauthorized - upstream_unavailable - venue_auth_failed - venue_leg_unverified - venue_not_connected - venue_not_listed - venue_rejected - venue_unavailable - venue_unsupported message: description: a human-readable explanation; never parse it title: Message type: string request_id: description: >- this request's id, also sent as the X-Request-Id header; quote it when asking for help title: Request Id type: string required: - code - message - request_id title: PublicErrorBody type: object securitySchemes: HTTPBearer: description: 'Authorization: Bearer tl_live_…' scheme: bearer type: http ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.