> ## Documentation Index > Fetch the complete documentation index at: https://docs.polymarket.com/llms.txt > Use this file to discover all available pages before exploring further. # BBO > Perps WebSocket best bid and offer updates. ## AsyncAPI ````yaml asyncapi-perps.json bbo id: bbo title: BBO description: Best bid and offer real-time updates. servers: - id: production protocol: wss host: ws.perpetuals.polymarket.com bindings: [] variables: [] address: /v1/ws parameters: [] bindings: [] operations: - &ref_1 id: BBOSubscribe title: B b o subscribe description: Subscribe to BBO type: receive messages: - &ref_6 id: SubscribeRequest contentType: application/json payload: - name: Subscribe description: Subscribe to BBO updates for a specific instrument type: object properties: - name: id type: integer description: Correlation ID for request-response matching required: false - name: req type: string description: Request type enumValues: - post - sub - unsub required: true - name: chs type: array description: | BBO subscription per instrument: `bbo::{iid}` (e.g. `bbo::1`). required: true properties: - name: item type: string required: false headers: [] jsonPayloadSchema: type: object title: Base Request properties: id: type: integer description: Correlation ID for request-response matching x-parser-schema-id: req: type: string description: Request type enum: - post - sub - unsub x-parser-schema-id: chs: type: array description: | BBO subscription per instrument: `bbo::{iid}` (e.g. `bbo::1`). items: type: string pattern: ^bbo::\d+$ x-parser-schema-id: example: - bbo::1 x-parser-schema-id: required: - req - chs x-parser-schema-id: title: Subscribe description: Subscribe to BBO updates for a specific instrument example: |- { "req": "sub", "chs": [ "bbo::1" ] } bindings: [] extensions: - id: x-parser-unique-object-id value: SubscribeRequest bindings: [] extensions: &ref_0 - id: x-parser-unique-object-id value: bbo - &ref_3 id: BBOSubscribeResponse title: B b o subscribe response description: BBO subscribe response type: send messages: - &ref_8 id: SubscribeResponse contentType: application/json payload: - name: Subscribe Response description: Response to BBO subscribe request type: object properties: - name: id type: integer description: Correlation ID for request-response matching required: false - name: data type: array title: Subscribe Response required: true properties: - name: item type: object required: false properties: - name: status type: string enumValues: - ok required: true - name: status type: string enumValues: - err required: true - name: error type: string description: >- Error identifier. For domain rejections and transport errors (`401`/`404`/`429`/`500`) this is a stable, machine-readable snake_case identifier that is part of the API contract and safe to branch on, e.g. `insufficient_margin`, `insufficient_balance`, `order_not_found`, `reduce_only_invalid`, `unauthorized`, `not_found`. For `400` it is a human-readable validation detail whose wording may change. See the Error handling guide for the domain identifiers. (Post-only / Fill-or-Kill outcomes are order statuses such as `post_only_rejected`, not rejections.) required: true headers: [] jsonPayloadSchema: type: object title: Base Response properties: id: type: integer description: Correlation ID for request-response matching x-parser-schema-id: data: title: Subscribe Response type: array items: oneOf: - type: object required: - status properties: status: type: string enum: - ok x-parser-schema-id: x-parser-schema-id: - type: object required: - status - error properties: status: type: string enum: - err x-parser-schema-id: error: type: string description: >- Error identifier. For domain rejections and transport errors (`401`/`404`/`429`/`500`) this is a stable, machine-readable snake_case identifier that is part of the API contract and safe to branch on, e.g. `insufficient_margin`, `insufficient_balance`, `order_not_found`, `reduce_only_invalid`, `unauthorized`, `not_found`. For `400` it is a human-readable validation detail whose wording may change. See the Error handling guide for the domain identifiers. (Post-only / Fill-or-Kill outcomes are order statuses such as `post_only_rejected`, not rejections.) example: insufficient_margin x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: required: - data x-parser-schema-id: title: Subscribe Response description: Response to BBO subscribe request example: |- { "data": [] } bindings: [] extensions: - id: x-parser-unique-object-id value: SubscribeResponse bindings: [] extensions: *ref_0 - &ref_2 id: BBOUnsubscribe title: B b o unsubscribe description: Unsubscribe from BBO type: receive messages: - &ref_7 id: UnsubscribeRequest contentType: application/json payload: - name: Unsubscribe description: Unsubscribe from BBO updates type: object properties: - name: id type: integer description: Correlation ID for request-response matching required: false - name: req type: string description: Request type enumValues: - post - sub - unsub required: true - name: chs type: array description: | BBO subscription per instrument: `bbo::{iid}` (e.g. `bbo::1`). required: true properties: - name: item type: string required: false headers: [] jsonPayloadSchema: type: object title: Base Request properties: id: type: integer description: Correlation ID for request-response matching x-parser-schema-id: req: type: string description: Request type enum: - post - sub - unsub x-parser-schema-id: chs: type: array description: | BBO subscription per instrument: `bbo::{iid}` (e.g. `bbo::1`). items: type: string pattern: ^bbo::\d+$ x-parser-schema-id: example: - bbo::1 x-parser-schema-id: required: - req - chs x-parser-schema-id: title: Unsubscribe description: Unsubscribe from BBO updates example: |- { "req": "unsub", "chs": [ "bbo::1" ] } bindings: [] extensions: - id: x-parser-unique-object-id value: UnsubscribeRequest bindings: [] extensions: *ref_0 - &ref_4 id: BBOUnsubscribeResponse title: B b o unsubscribe response description: BBO unsubscribe response type: send messages: - &ref_9 id: UnsubscribeResponse contentType: application/json payload: - name: Unsubscribe Response description: Response to BBO unsubscribe request type: object properties: - name: id type: integer description: Correlation ID for request-response matching required: false - name: data type: array title: Subscribe Response required: true properties: - name: item type: object required: false properties: - name: status type: string enumValues: - ok required: true - name: status type: string enumValues: - err required: true - name: error type: string description: >- Error identifier. For domain rejections and transport errors (`401`/`404`/`429`/`500`) this is a stable, machine-readable snake_case identifier that is part of the API contract and safe to branch on, e.g. `insufficient_margin`, `insufficient_balance`, `order_not_found`, `reduce_only_invalid`, `unauthorized`, `not_found`. For `400` it is a human-readable validation detail whose wording may change. See the Error handling guide for the domain identifiers. (Post-only / Fill-or-Kill outcomes are order statuses such as `post_only_rejected`, not rejections.) required: true headers: [] jsonPayloadSchema: type: object title: Base Response properties: id: type: integer description: Correlation ID for request-response matching x-parser-schema-id: data: title: Subscribe Response type: array items: oneOf: - type: object required: - status properties: status: type: string enum: - ok x-parser-schema-id: x-parser-schema-id: - type: object required: - status - error properties: status: type: string enum: - err x-parser-schema-id: error: type: string description: >- Error identifier. For domain rejections and transport errors (`401`/`404`/`429`/`500`) this is a stable, machine-readable snake_case identifier that is part of the API contract and safe to branch on, e.g. `insufficient_margin`, `insufficient_balance`, `order_not_found`, `reduce_only_invalid`, `unauthorized`, `not_found`. For `400` it is a human-readable validation detail whose wording may change. See the Error handling guide for the domain identifiers. (Post-only / Fill-or-Kill outcomes are order statuses such as `post_only_rejected`, not rejections.) example: insufficient_margin x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: x-parser-schema-id: required: - data x-parser-schema-id: title: Unsubscribe Response description: Response to BBO unsubscribe request example: |- { "data": [] } bindings: [] extensions: - id: x-parser-unique-object-id value: UnsubscribeResponse bindings: [] extensions: *ref_0 - &ref_5 id: BBOUpdate title: B b o update description: Receive BBO updates type: send messages: - &ref_10 id: Update contentType: application/json payload: - name: Update description: Real-time BBO updates for subscribed instruments type: object properties: - name: ch type: string description: >- Channel name for push data. Parameterized channels include the instrument ID (e.g. "trades::1", "book::1", "klines::1::1m", "tickers::all"). Private channels use plain names (e.g. "fills", "orders"). required: true - name: ts type: integer description: >- Request timestamp. Unix milliseconds for most operations; Unix seconds for withdrawals (must match the on-chain EIP-712 struct verified against block.timestamp). required: true - name: sq type: integer description: Sequence number required: true - name: data type: object title: BBO Data description: BBO object required: true properties: - name: iid type: integer description: Instrument ID required: true - name: bp type: string description: Best bid price required: true - name: bq type: string description: Best bid quantity required: true - name: ap type: string description: Best ask price required: true - name: aq type: string description: Best ask quantity required: true headers: [] jsonPayloadSchema: title: BBO Update type: object properties: ch: type: string description: >- Channel name for push data. Parameterized channels include the instrument ID (e.g. "trades::1", "book::1", "klines::1::1m", "tickers::all"). Private channels use plain names (e.g. "fills", "orders"). example: trades::1 x-parser-schema-id: ts: type: integer description: >- Request timestamp. Unix milliseconds for most operations; Unix seconds for withdrawals (must match the on-chain EIP-712 struct verified against block.timestamp). example: 1767225600000 x-parser-schema-id: sq: type: integer description: Sequence number example: 1234567890 x-parser-schema-id: data: type: object description: BBO object title: BBO Data properties: iid: type: integer description: Instrument ID example: 1 x-parser-schema-id: bp: type: string description: Best bid price example: '99.50' x-parser-schema-id: bq: type: string description: Best bid quantity example: '10.00' x-parser-schema-id: ap: type: string description: Best ask price example: '100.50' x-parser-schema-id: aq: type: string description: Best ask quantity example: '10.00' x-parser-schema-id: required: - iid - bp - bq - ap - aq x-parser-schema-id: required: - ch - ts - sq - data x-parser-schema-id: title: Update description: Real-time BBO updates for subscribed instruments example: |- { "ch": "bbo::1", "ts": 1767225600000, "sq": 1234567890, "data": { "iid": 1, "bp": "99.50", "bq": "10.00", "ap": "100.50", "aq": "10.00" } } bindings: [] extensions: - id: x-parser-unique-object-id value: Update bindings: [] extensions: *ref_0 sendOperations: - *ref_1 - *ref_2 receiveOperations: - *ref_3 - *ref_4 - *ref_5 sendMessages: - *ref_6 - *ref_7 receiveMessages: - *ref_8 - *ref_9 - *ref_10 extensions: - id: x-parser-unique-object-id value: bbo securitySchemes: [] ````