> ## Documentation Index > Fetch the complete documentation index at: https://docs.predexon.com/llms.txt > Use this file to discover all available pages before exploring further. # Orderbook Playground > Real-time L2 orderbook from Polymarket CLOB. Exactly one filter type per subscription. ## AsyncAPI ````yaml websocket/asyncapi.json orderbook id: orderbook title: Orderbook description: >- Real-time L2 orderbook from Polymarket CLOB. Exactly one filter type per subscription. servers: - id: production protocol: wss host: wss.predexon.com bindings: [] variables: [] address: / parameters: [] bindings: [] operations: - &ref_1 id: sendSubscribeOrderbook title: Send subscribe orderbook type: receive messages: - &ref_11 id: SubscribeOrderbook payload: - name: Subscribe to Orderbook description: >- Exactly ONE of token_ids, condition_ids, or market_slugs. No users filter. type: object properties: - name: action type: string description: Must be 'subscribe' required: true - name: platform type: string description: Must be 'polymarket' required: true - name: version type: integer description: Must be 1 required: true - name: type type: string description: Must be 'orderbook' required: true - name: filters type: object description: Exactly one filter key required: true properties: - name: token_ids type: array description: CLOB token IDs required: false properties: - name: item type: string required: false - name: condition_ids type: array description: Market condition IDs required: false properties: - name: item type: string required: false - name: market_slugs type: array description: Market URL slugs required: false properties: - name: item type: string required: false headers: [] jsonPayloadSchema: type: object required: - action - platform - version - type - filters properties: action: type: string description: Must be 'subscribe' x-parser-schema-id: platform: type: string description: Must be 'polymarket' x-parser-schema-id: version: type: integer description: Must be 1 x-parser-schema-id: type: type: string description: Must be 'orderbook' x-parser-schema-id: filters: type: object description: Exactly one filter key properties: token_ids: type: array description: CLOB token IDs items: type: string x-parser-schema-id: x-parser-schema-id: condition_ids: type: array description: Market condition IDs items: type: string x-parser-schema-id: x-parser-schema-id: market_slugs: type: array description: Market URL slugs items: type: string x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: examples: - action: subscribe platform: polymarket version: 1 type: orderbook filters: market_slugs: - bitcoin-100k-2026 x-parser-schema-id: title: Subscribe to Orderbook description: >- Exactly ONE of token_ids, condition_ids, or market_slugs. No users filter. example: |- { "action": "subscribe", "platform": "polymarket", "version": 1, "type": "orderbook", "filters": { "market_slugs": [ "bitcoin-100k-2026" ] } } bindings: [] extensions: - id: x-parser-unique-object-id value: SubscribeOrderbook - id: x-parser-message-name value: SubscribeOrderbook bindings: [] extensions: &ref_0 - id: x-mint value: &ref_21 content: >- WebSocket requires a **Dev** or **Pro** API key. Free tier keys cannot connect. [Get your key →](https://dashboard.predexon.com) - id: x-parser-unique-object-id value: orderbook - &ref_2 id: sendUnsubscribeOrderbook title: Send unsubscribe orderbook type: receive messages: - &ref_12 id: Unsubscribe payload: - name: Unsubscribe description: Remove a subscription by ID. type: object properties: - name: action type: string description: Must be 'unsubscribe' required: true - name: subscription_id type: string description: Subscription ID from the ack response (e.g. sub_2f4b15b33798) required: true headers: [] jsonPayloadSchema: type: object required: - action - subscription_id properties: action: type: string description: Must be 'unsubscribe' x-parser-schema-id: subscription_id: type: string description: Subscription ID from the ack response (e.g. sub_2f4b15b33798) x-parser-schema-id: examples: - action: unsubscribe subscription_id: sub_2f4b15b33798 x-parser-schema-id: title: Unsubscribe description: Remove a subscription by ID. example: |- { "action": "unsubscribe", "subscription_id": "sub_2f4b15b33798" } bindings: [] extensions: - id: x-parser-unique-object-id value: Unsubscribe - id: x-parser-message-name value: Unsubscribe bindings: [] extensions: *ref_0 - &ref_3 id: receiveAckOrderbook title: Receive ack orderbook type: send messages: - &ref_13 id: Ack payload: - name: Acknowledgement description: >- Server acknowledgement for subscribe, unsubscribe, and update actions. type: object properties: - name: type type: string description: ack required: true - name: subscription_id type: string description: The subscription ID required: true - name: channel type: string description: >- Channel name (trades, activity, lifecycle, orderbook, oracle, collateral, crypto_prices) required: true headers: [] jsonPayloadSchema: type: object properties: type: type: string description: ack x-parser-schema-id: subscription_id: type: string description: The subscription ID x-parser-schema-id: channel: type: string description: >- Channel name (trades, activity, lifecycle, orderbook, oracle, collateral, crypto_prices) x-parser-schema-id: required: - type - subscription_id - channel examples: - type: ack subscription_id: sub_2f4b15b33798 channel: trades x-parser-schema-id: title: Acknowledgement description: Server acknowledgement for subscribe, unsubscribe, and update actions. example: |- { "type": "ack", "subscription_id": "sub_2f4b15b33798", "channel": "trades" } bindings: [] extensions: - id: x-parser-unique-object-id value: Ack - id: x-parser-message-name value: Ack bindings: [] extensions: *ref_0 - &ref_4 id: receiveBookSnapshot title: Receive book snapshot type: send messages: - &ref_14 id: BookSnapshot payload: - name: Book Snapshot description: Full orderbook snapshot sent on subscribe. type: object properties: - name: event_type type: string description: book_snapshot required: true - name: token_id type: string description: CLOB token ID required: true - name: condition_id type: string description: Market condition ID required: false - name: slug type: string description: Market URL slug required: false - name: question type: string description: Market question (snapshot only) required: false - name: event_title type: string description: Parent event title (snapshot only) required: false - name: outcome type: string description: Yes or No required: true - name: timestamp type: integer description: Unix timestamp in milliseconds required: true - name: bids type: array description: Aggregated buy orders required: true properties: - name: price type: string required: false - name: size type: string required: false - name: asks type: array description: Aggregated sell orders required: true properties: - name: price type: string required: false - name: size type: string required: false - name: hash type: string description: Hash of orderbook content required: false headers: [] jsonPayloadSchema: type: object properties: event_type: type: string description: book_snapshot x-parser-schema-id: token_id: type: string description: CLOB token ID x-parser-schema-id: condition_id: type: string description: Market condition ID x-parser-schema-id: slug: type: string description: Market URL slug x-parser-schema-id: question: type: string description: Market question (snapshot only) x-parser-schema-id: event_title: type: string description: Parent event title (snapshot only) x-parser-schema-id: outcome: type: string description: Yes or No x-parser-schema-id: timestamp: type: integer description: Unix timestamp in milliseconds x-parser-schema-id: bids: type: array description: Aggregated buy orders items: type: object properties: price: type: string x-parser-schema-id: size: type: string x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: asks: type: array description: Aggregated sell orders items: type: object properties: price: type: string x-parser-schema-id: size: type: string x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: hash: type: string description: Hash of orderbook content x-parser-schema-id: required: - event_type - token_id - outcome - timestamp - bids - asks examples: - event_type: book_snapshot token_id: 82855... condition_id: 0x4c57... slug: bitcoin-100k-2026 question: Will Bitcoin hit $100k? outcome: 'Yes' timestamp: 1775196804071 bids: - price: '0.48' size: '5000' asks: - price: '0.52' size: '3000' hash: abc123... x-parser-schema-id: title: Book Snapshot description: Full orderbook snapshot sent on subscribe. example: |- { "event_type": "book_snapshot", "token_id": "82855...", "condition_id": "0x4c57...", "slug": "bitcoin-100k-2026", "question": "Will Bitcoin hit $100k?", "outcome": "Yes", "timestamp": 1775196804071, "bids": [ { "price": "0.48", "size": "5000" } ], "asks": [ { "price": "0.52", "size": "3000" } ], "hash": "abc123..." } bindings: [] extensions: - id: x-parser-unique-object-id value: BookSnapshot - id: x-parser-message-name value: BookSnapshot bindings: [] extensions: *ref_0 - &ref_5 id: receivePriceChange title: Receive price change type: send messages: - &ref_15 id: PriceChange payload: - name: Price Change description: Orderbook price level delta. Size '0' means level removed. type: object properties: - name: event_type type: string description: price_change required: true - name: token_id type: string description: CLOB token ID required: true - name: condition_id type: string required: false - name: slug type: string required: false - name: outcome type: string required: false - name: timestamp type: integer description: Unix milliseconds required: true - name: side type: string description: BUY (bid) or SELL (ask) enumValues: - BUY - SELL required: true - name: price type: string description: Price level (0 to 1) required: true - name: size type: string description: New aggregate size. '0' = removed. required: true - name: best_bid type: string description: Current best bid required: false - name: best_ask type: string description: Current best ask required: false headers: [] jsonPayloadSchema: type: object properties: event_type: type: string description: price_change x-parser-schema-id: token_id: type: string description: CLOB token ID x-parser-schema-id: condition_id: type: string x-parser-schema-id: slug: type: string x-parser-schema-id: outcome: type: string x-parser-schema-id: timestamp: type: integer description: Unix milliseconds x-parser-schema-id: side: type: string description: BUY (bid) or SELL (ask) enum: - BUY - SELL x-parser-schema-id: price: type: string description: Price level (0 to 1) x-parser-schema-id: size: type: string description: New aggregate size. '0' = removed. x-parser-schema-id: best_bid: type: string description: Current best bid x-parser-schema-id: best_ask: type: string description: Current best ask x-parser-schema-id: required: - event_type - token_id - timestamp - side - price - size examples: - event_type: price_change token_id: 82855... condition_id: 0x4c57... slug: bitcoin-100k-2026 outcome: 'Yes' timestamp: 1775196805000 side: BUY price: '0.50' size: '7500' best_bid: '0.50' best_ask: '0.52' x-parser-schema-id: title: Price Change description: Orderbook price level delta. Size '0' means level removed. example: |- { "event_type": "price_change", "token_id": "82855...", "condition_id": "0x4c57...", "slug": "bitcoin-100k-2026", "outcome": "Yes", "timestamp": 1775196805000, "side": "BUY", "price": "0.50", "size": "7500", "best_bid": "0.50", "best_ask": "0.52" } bindings: [] extensions: - id: x-parser-unique-object-id value: PriceChange - id: x-parser-message-name value: PriceChange bindings: [] extensions: *ref_0 - &ref_6 id: receiveLastTrade title: Receive last trade type: send messages: - &ref_16 id: LastTrade payload: - name: Last Trade description: Trade execution on the orderbook channel. type: object properties: - name: event_type type: string description: last_trade required: true - name: token_id type: string required: true - name: condition_id type: string required: false - name: slug type: string required: false - name: outcome type: string required: false - name: timestamp type: integer description: Unix milliseconds required: true - name: side type: string description: Taker's side enumValues: - BUY - SELL required: true - name: price type: string description: Execution price required: true - name: size type: string description: Trade size required: true - name: fee_rate_bps type: string description: Fee rate in basis points required: false headers: [] jsonPayloadSchema: type: object properties: event_type: type: string description: last_trade x-parser-schema-id: token_id: type: string x-parser-schema-id: condition_id: type: string x-parser-schema-id: slug: type: string x-parser-schema-id: outcome: type: string x-parser-schema-id: timestamp: type: integer description: Unix milliseconds x-parser-schema-id: side: type: string description: Taker's side enum: - BUY - SELL x-parser-schema-id: price: type: string description: Execution price x-parser-schema-id: size: type: string description: Trade size x-parser-schema-id: fee_rate_bps: type: string description: Fee rate in basis points x-parser-schema-id: required: - event_type - token_id - timestamp - side - price - size examples: - event_type: last_trade token_id: 82855... condition_id: 0x4c57... slug: bitcoin-100k-2026 outcome: 'Yes' timestamp: 1775196806000 side: BUY price: '0.46' size: '219.22' fee_rate_bps: '0' x-parser-schema-id: title: Last Trade description: Trade execution on the orderbook channel. example: |- { "event_type": "last_trade", "token_id": "82855...", "condition_id": "0x4c57...", "slug": "bitcoin-100k-2026", "outcome": "Yes", "timestamp": 1775196806000, "side": "BUY", "price": "0.46", "size": "219.22", "fee_rate_bps": "0" } bindings: [] extensions: - id: x-parser-unique-object-id value: LastTrade - id: x-parser-message-name value: LastTrade bindings: [] extensions: *ref_0 - &ref_7 id: receiveTickSizeChange title: Receive tick size change type: send messages: - &ref_17 id: TickSizeChange payload: - name: Tick Size Change description: Emitted when a market's tick size changes. type: object properties: - name: event_type type: string description: tick_size_change required: true - name: token_id type: string description: CLOB token ID required: true - name: condition_id type: string required: false - name: slug type: string required: false - name: outcome type: string required: false - name: timestamp type: integer description: Unix milliseconds required: true - name: tick_size type: string description: New tick size value (e.g. '0.001') required: true headers: [] jsonPayloadSchema: type: object properties: event_type: type: string description: tick_size_change x-parser-schema-id: token_id: type: string description: CLOB token ID x-parser-schema-id: condition_id: type: string x-parser-schema-id: slug: type: string x-parser-schema-id: outcome: type: string x-parser-schema-id: timestamp: type: integer description: Unix milliseconds x-parser-schema-id: tick_size: type: string description: New tick size value (e.g. '0.001') x-parser-schema-id: required: - event_type - token_id - timestamp - tick_size examples: - event_type: tick_size_change token_id: 82855... condition_id: 0x4c57... slug: bitcoin-100k-2026 outcome: 'Yes' timestamp: 1775196807000 tick_size: '0.001' x-parser-schema-id: title: Tick Size Change description: Emitted when a market's tick size changes. example: |- { "event_type": "tick_size_change", "token_id": "82855...", "condition_id": "0x4c57...", "slug": "bitcoin-100k-2026", "outcome": "Yes", "timestamp": 1775196807000, "tick_size": "0.001" } bindings: [] extensions: - id: x-parser-unique-object-id value: TickSizeChange - id: x-parser-message-name value: TickSizeChange bindings: [] extensions: *ref_0 - &ref_8 id: receiveSnapshotsDone title: Receive snapshots done type: send messages: - &ref_18 id: SnapshotsDone payload: - name: Snapshots Done description: Marker sent after all initial book snapshots have been delivered. type: object properties: - name: event_type type: string description: snapshots_done required: true - name: count type: integer description: Number of book_snapshot events sent required: true headers: [] jsonPayloadSchema: type: object properties: event_type: type: string description: snapshots_done x-parser-schema-id: count: type: integer description: Number of book_snapshot events sent x-parser-schema-id: required: - event_type - count examples: - event_type: snapshots_done count: 2 x-parser-schema-id: title: Snapshots Done description: Marker sent after all initial book snapshots have been delivered. example: |- { "event_type": "snapshots_done", "count": 2 } bindings: [] extensions: - id: x-parser-unique-object-id value: SnapshotsDone - id: x-parser-message-name value: SnapshotsDone bindings: [] extensions: *ref_0 - &ref_9 id: receiveEventBatch title: Receive event batch type: send messages: - &ref_19 id: EventBatch payload: - name: Event Batch description: >- Wildcard/firehose only. Batched every ~250ms with price-level conflation. type: object properties: - name: type type: string description: event_batch required: true - name: subscription_id type: string required: false - name: count type: integer description: Number of events in batch required: true - name: events type: array description: Array of price_change, last_trade, tick_size_change events required: true - name: gap type: boolean description: true if events were missed. Rebuild from next snapshot. required: false headers: [] jsonPayloadSchema: type: object properties: type: type: string description: event_batch x-parser-schema-id: subscription_id: type: string x-parser-schema-id: count: type: integer description: Number of events in batch x-parser-schema-id: events: type: array description: Array of price_change, last_trade, tick_size_change events x-parser-schema-id: gap: type: boolean description: true if events were missed. Rebuild from next snapshot. x-parser-schema-id: required: - type - count - events examples: - type: event_batch subscription_id: sub_xxx count: 350 events: [] gap: false x-parser-schema-id: title: Event Batch description: >- Wildcard/firehose only. Batched every ~250ms with price-level conflation. example: |- { "type": "event_batch", "subscription_id": "sub_xxx", "count": 350, "events": [], "gap": false } bindings: [] extensions: - id: x-parser-unique-object-id value: EventBatch - id: x-parser-message-name value: EventBatch bindings: [] extensions: *ref_0 - &ref_10 id: receiveResync title: Receive resync type: send messages: - &ref_20 id: Resync payload: - name: Resync description: >- Sent after internal reconnect. Discard local state — fresh snapshots will follow. type: object properties: - name: event_type type: string description: resync required: true headers: [] jsonPayloadSchema: type: object properties: event_type: type: string description: resync x-parser-schema-id: required: - event_type examples: - event_type: resync x-parser-schema-id: title: Resync description: >- Sent after internal reconnect. Discard local state — fresh snapshots will follow. example: |- { "event_type": "resync" } bindings: [] extensions: - id: x-parser-unique-object-id value: Resync - id: x-parser-message-name value: Resync bindings: [] extensions: *ref_0 sendOperations: - *ref_1 - *ref_2 receiveOperations: - *ref_3 - *ref_4 - *ref_5 - *ref_6 - *ref_7 - *ref_8 - *ref_9 - *ref_10 sendMessages: - *ref_11 - *ref_12 receiveMessages: - *ref_13 - *ref_14 - *ref_15 - *ref_16 - *ref_17 - *ref_18 - *ref_19 - *ref_20 extensions: - id: x-mint value: *ref_21 - id: x-parser-unique-object-id value: orderbook securitySchemes: - id: apiKey name: api_key type: httpApiKey description: Your Predexon API key in: query extensions: [] ````