> ## Documentation Index > Fetch the complete documentation index at: https://docs.routeur.app/llms.txt > Use this file to discover all available pages before exploring further. # Order book > The market's order book: both outcomes' bids and asks to the depth asked, best first, with the top of book, the USD resting within 1, 2 and 5 cents of each side's best bid, the imbalance between the sides, and the market's liquidity grade. Books are recorded from the venues' own feeds. Markets graded tradeable or deep, markets in a current lead, and markets of followed events are recorded at full depth as every level changes (`tier` is `full`); every other listed market is polled over REST, five levels per side, once a cycle (`tier` is `rest`; `/v1/books/health` gives the cycle time). A Yes ask is a No bid at the complementary price: the two outcomes' ladders are one book seen from each side. Without `at`, the book is the latest recorded, rebuilt from the last snapshot and every level change since (`source` is `live`; `as_of` is when the last change was received, and `feed` says whether the venue feed is connected). With `at`, the book as it stood at that moment (`source` is `rebuilt`), from up to 90 days back while events are still hot; older history is in the daily Parquet export. Prices are per contract that pays $1; quantities are contracts on Kalshi and outcome shares on Polymarket. ## OpenAPI ````yaml /openapi.yaml get /v1/markets/{venue}/{id}/book openapi: 3.1.0 info: title: Routeur Graph API version: '2026-09-15' summary: >- Proven relations between Kalshi and Polymarket contracts, with the history and signals built on them. description: > Routeur reads every open market on Kalshi and global Polymarket, and proves which ones imply, exclude or equal each other from each venue's structured contract terms and exact arithmetic. No relation is inferred from prose, and ambiguous or conflicting evidence is withheld. ## Authentication Send your key in the `X-API-Key` header, or as `Authorization: Bearer `. Keys look like `rk_live_<12-character id>_<43-character secret>` and are shown once when issued. Keep them server-side. ## Rate limits Every key has a per-minute limit and a per-day quota set by its tier: | Tier | Requests per minute | Requests per day | |---|---|---| | free | 30 | 2,000 | | trader | 120 | 50,000 | | pro | 600 | 500,000 | | institutional | 3,000 | 10,000,000 | Responses carry `X-RateLimit-Limit`, `X-RateLimit-Remaining` and `X-RateLimit-Reset` (Unix seconds) for the minute window, and `X-Daily-Quota-Limit` and `X-Daily-Quota-Remaining` for the day (UTC). A request over either limit returns `429` with `Retry-After` in seconds. ## Conventions - Money and prices are decimal strings in USD (for example `"0.4100"`), never floats. Prices are per contract that pays $1. - Times are RFC 3339 in UTC. - Successful responses wrap results in `data`. Graph-derived responses also name the `graph_run` they were read from; runs finish hourly. - Paginated lists return `next_cursor` when more results exist. Pass it back as `cursor` unchanged; cursors are opaque. - Unknown or repeated query parameters are rejected with `400`, so typos never silently widen a query. ## Liquidity Every object that names a market carries its 24-hour volume, its spread and a `liquidity` grade, because a price nobody can trade at is not a price: | Grade | 24-hour volume or open interest | Round-trip spread | |---|---|---| | `deep` | $25,000 traded, or $250,000 open interest | 2¢ or less | | `tradeable` | $1,000 traded, or $25,000 open interest | 5¢ or less | | `thin` | anything less, or no quoted round trip | | Lists that suggest something to act on — price gaps, leads, movers, flows, large fills, closing soon, strategy matches — leave thin markets out by default, and rank what is left by the money behind it. Three parameters change that wherever it applies: `min_volume_usd`, `max_spread_usd` and `include_thin=true`, which drops both floors. Search and event listings show thin markets but rank them below what can be traded. ## Errors Errors return a JSON body `{"error": {"code": "...", "message": "..."}}`. Branch on `code`; messages may change. | Status | Code | Meaning | |---|---|---| | 400 | `invalid_parameter` | A query parameter is unknown, repeated or out of range. | | 400 | `invalid_market` | The venue is not `kalshi` or `polymarket`, or the market id is malformed. | | 400 | `invalid_rulebook` | The venue, rulebook kind or id is malformed. | | 401 | `api_key_required` | No key was sent. | | 401 | `invalid_api_key` | The key is malformed or unknown. | | 401 | `api_key_revoked` | The key was revoked. | | 404 | `market_not_found` | The market is not in the latest graph. | | 404 | `relation_not_found` | Both markets are listed, but no current proof relates them. | | 404 | `rulebook_not_found` | No such rulebook has been recorded. | | 404 | `book_not_found` | No order book is recorded for the market at that time. | | 404 | `not_found` | No such endpoint. | | 429 | `rate_limited` | The per-minute limit was exceeded. | | 429 | `daily_quota_exceeded` | The daily quota is used up. | | 429 | `too_many_streams` | The key already holds its concurrent live streams. | | 503 | `graph_unavailable` | No graph run has finished yet. | | 503 | `stream_unavailable` | No live stream capacity is free; retry shortly. | | 504 | `timeout` | The request took longer than 15 seconds. | | 500 | `internal` | Something failed on our side. | ## Webhooks Mispricing alerts are delivered as signed `POST` requests; see the `webhooks` section. Each request carries `Routeur-Signature: t=,v1=`, where `v1` is HMAC-SHA256 of `.` keyed by your subscription's signing secret. Reject requests whose signature does not match or whose `t` is more than five minutes old, and respond `2xx` within 10 seconds. `Routeur-Delivery` identifies the delivery and stays the same across retries, so use it to ignore duplicates. Any response other than `2xx` or `410`, or no response, is retried with exponential backoff from 30 seconds for up to 8 attempts; responding `410 Gone` disables the subscription. Endpoints must be HTTPS on a public address, and redirects are not followed. contact: name: Routeur url: https://routeur.app servers: - url: https://api.routeur.app security: - apiKey: [] - bearer: [] tags: - name: Events description: Real-world events across both venues, the way people browse them. - name: Graph description: Markets and the relations proven between them. - name: History description: Recorded quotes and trades. - name: Rules description: | Contract terms and their history. Every version of every market's rule text is kept from the day it was first seen, along with the rulebooks above it (Kalshi series and event terms, Polymarket resolution metadata) and the venue's contract terms documents, with diffs between versions. - name: Books description: >- Order books recorded live from each venue's feed, their history, and the health of the feeds. - name: Signals description: Mispricing leads and unusual trading derived from the graph and history. - name: Live description: Quotes, trades, relations and leads pushed as they happen. - name: Service description: Service status and this document. paths: /v1/markets/{venue}/{id}/book: parameters: - $ref: '#/components/parameters/Venue' - $ref: '#/components/parameters/MarketID' get: tags: - Books summary: Order book description: | The market's order book: both outcomes' bids and asks to the depth asked, best first, with the top of book, the USD resting within 1, 2 and 5 cents of each side's best bid, the imbalance between the sides, and the market's liquidity grade. Books are recorded from the venues' own feeds. Markets graded tradeable or deep, markets in a current lead, and markets of followed events are recorded at full depth as every level changes (`tier` is `full`); every other listed market is polled over REST, five levels per side, once a cycle (`tier` is `rest`; `/v1/books/health` gives the cycle time). A Yes ask is a No bid at the complementary price: the two outcomes' ladders are one book seen from each side. Without `at`, the book is the latest recorded, rebuilt from the last snapshot and every level change since (`source` is `live`; `as_of` is when the last change was received, and `feed` says whether the venue feed is connected). With `at`, the book as it stood at that moment (`source` is `rebuilt`), from up to 90 days back while events are still hot; older history is in the daily Parquet export. Prices are per contract that pays $1; quantities are contracts on Kalshi and outcome shares on Polymarket. operationId: getMarketBook parameters: - name: depth in: query description: Levels per side to return. schema: type: integer minimum: 1 maximum: 100 default: 10 - name: at in: query description: >- The moment to rebuild the book at, RFC 3339. Omit for the latest book. schema: type: string format: date-time example: '2026-09-16T14:30:00Z' responses: '200': description: The book. headers: X-RateLimit-Limit: $ref: '#/components/headers/X-RateLimit-Limit' X-RateLimit-Remaining: $ref: '#/components/headers/X-RateLimit-Remaining' X-RateLimit-Reset: $ref: '#/components/headers/X-RateLimit-Reset' X-Daily-Quota-Limit: $ref: '#/components/headers/X-Daily-Quota-Limit' X-Daily-Quota-Remaining: $ref: '#/components/headers/X-Daily-Quota-Remaining' content: application/json: schema: type: object additionalProperties: false required: - data properties: data: $ref: '#/components/schemas/Book' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '404': description: >- No order book is recorded for the market at that time (`book_not_found`). content: application/json: schema: $ref: '#/components/schemas/Error' '429': $ref: '#/components/responses/TooManyRequests' default: $ref: '#/components/responses/Error' components: parameters: Venue: name: venue in: path required: true description: The venue the market is listed on. schema: $ref: '#/components/schemas/Venue' example: kalshi MarketID: name: id in: path required: true description: >- The venue's market id, such as a Kalshi ticker or a Polymarket market slug. schema: $ref: '#/components/schemas/MarketID' example: KXNFLTEAMTOTAL-26SEP20MIASF-SF11 headers: X-RateLimit-Limit: description: Requests allowed per minute for this key. schema: type: integer X-RateLimit-Remaining: description: Requests left in the current minute. schema: type: integer X-RateLimit-Reset: description: Unix time when the minute window resets. schema: type: integer X-Daily-Quota-Limit: description: Requests allowed per UTC day. schema: type: integer X-Daily-Quota-Remaining: description: Requests left today. schema: type: integer schemas: Book: type: object additionalProperties: false required: - venue - market_id - source - tier - as_of - snapshot_at - events_applied - depth - 'yes' - 'no' - top - feed - issues - volume_24h_usd - trades_24h - liquidity properties: volume_24h_usd: $ref: '#/components/schemas/Decimal' description: > Traded in the last 24 hours, in USD. The venue's own figure where it publishes one (Kalshi counts contracts at their $1 face value, as its own site does; Polymarket reports USDC notional), otherwise the notional of the fills this platform recorded. `volume_source` says which. volume_source: type: string enum: - venue - trades description: Where `volume_24h_usd` comes from. total_volume_usd: $ref: '#/components/schemas/Decimal' description: Traded over the market's life, where the venue reports it. open_interest_usd: $ref: '#/components/schemas/Decimal' description: Contracts currently held, at face value. Kalshi only. spread_usd: $ref: '#/components/schemas/Decimal' description: >- The round trip: the Yes ask plus the No ask less the $1 a winning contract pays. Absent when a side has no ask. yes_spread_usd: $ref: '#/components/schemas/Decimal' description: The Yes ask less the Yes bid, where the venue publishes a bid. no_spread_usd: $ref: '#/components/schemas/Decimal' description: The No ask less the No bid. trades_24h: type: integer description: Fills recorded in the last 24 hours. liquidity: $ref: '#/components/schemas/LiquidityGrade' book_spread_usd: $ref: '#/components/schemas/Decimal' description: >- From the recorded order book: the best Yes ask less the best Yes bid. Present for markets whose book is recorded. book_yes_depth_5c_usd: $ref: '#/components/schemas/Decimal' description: >- USD resting to buy Yes within 5 cents of the best Yes bid, from the recorded book. book_no_depth_5c_usd: $ref: '#/components/schemas/Decimal' description: >- USD resting to buy No within 5 cents of the best No bid (that is, to sell Yes), from the recorded book. book_imbalance: $ref: '#/components/schemas/Decimal' description: >- (Yes depth − No depth) / (Yes depth + No depth) over the 5-cent windows, from −1 to 1. book_at: $ref: '#/components/schemas/Timestamp' description: When the recorded book last changed. venue: $ref: '#/components/schemas/Venue' market_id: $ref: '#/components/schemas/MarketID' source: type: string enum: - live - rebuilt description: >- `live` is the latest recorded book; `rebuilt` is the book at the `at` asked for. tier: type: string enum: - full - rest description: >- `full`: every level change is recorded from the venue feed. `rest`: polled, five levels per side. as_of: $ref: '#/components/schemas/Timestamp' description: When the last change in this book was received. venue_ts: $ref: '#/components/schemas/Timestamp' description: The venue's own time on the last change, where it stamps one. seq: type: integer description: The venue's sequence number of the last change, where it has one. snapshot_at: $ref: '#/components/schemas/Timestamp' description: The snapshot the book was rebuilt from. events_applied: type: integer description: Level changes applied since the snapshot. depth: type: integer description: Levels per side asked for. 'yes': $ref: '#/components/schemas/BookSide' 'no': $ref: '#/components/schemas/BookSide' top: $ref: '#/components/schemas/BookTop' feed: type: object additionalProperties: false required: - connected - stale_seconds properties: connected: type: boolean description: Whether the venue feed is connected right now. last_message_at: $ref: '#/components/schemas/Timestamp' stale_seconds: type: integer description: Seconds since the book last changed; 0 for a rebuilt book. issues: type: array items: type: string description: 'Caveats: `polled`, `stale`, `truncated`.' Error: type: object additionalProperties: false required: - error properties: error: type: object additionalProperties: false required: - code - message properties: code: type: string description: A stable machine-readable code. message: type: string description: A human-readable explanation. Venue: type: string enum: - kalshi - polymarket MarketID: type: string pattern: ^[A-Za-z0-9][A-Za-z0-9_.-]{0,199}$ Decimal: type: string description: An exact decimal number. pattern: ^-?[0-9]+(\.[0-9]+)?$ example: '0.4100' LiquidityGrade: type: string description: | How tradeable a market is. `deep`: at least $25,000 traded in 24 hours or $250,000 of open interest, with a round trip of 2¢ or less. `tradeable`: at least $1,000 traded or $25,000 of open interest, with a round trip of 5¢ or less. `thin`: anything less, or no quoted round trip. Lists of suggestions leave thin markets out unless asked. enum: - deep - tradeable - thin Timestamp: type: string format: date-time BookSide: type: object description: >- One outcome's ladder, best first. Its asks are the other outcome's bids at the complementary price. additionalProperties: false required: - bids - asks properties: bids: type: array items: $ref: '#/components/schemas/BookLevel' asks: type: array items: $ref: '#/components/schemas/BookLevel' BookTop: type: object description: >- The top of the book in Yes terms. Depth is the USD resting within 1, 2 and 5 cents of each side's best bid (a level exactly that far counts); imbalance is (Yes − No) / (Yes + No) of the 5-cent depths. additionalProperties: false required: - yes_depth_1c_usd - yes_depth_2c_usd - yes_depth_5c_usd - no_depth_1c_usd - no_depth_2c_usd - no_depth_5c_usd properties: yes_bid_usd: $ref: '#/components/schemas/Decimal' yes_bid_quantity: $ref: '#/components/schemas/Decimal' yes_ask_usd: $ref: '#/components/schemas/Decimal' description: One less the best No bid. yes_ask_quantity: $ref: '#/components/schemas/Decimal' no_bid_usd: $ref: '#/components/schemas/Decimal' no_ask_usd: $ref: '#/components/schemas/Decimal' mid_usd: $ref: '#/components/schemas/Decimal' microprice_usd: $ref: '#/components/schemas/Decimal' description: >- The bid and ask weighed by the size resting at the other; leans toward the thinner side. spread_usd: $ref: '#/components/schemas/Decimal' description: Yes ask less Yes bid. yes_depth_1c_usd: $ref: '#/components/schemas/Decimal' yes_depth_2c_usd: $ref: '#/components/schemas/Decimal' yes_depth_5c_usd: $ref: '#/components/schemas/Decimal' no_depth_1c_usd: $ref: '#/components/schemas/Decimal' no_depth_2c_usd: $ref: '#/components/schemas/Decimal' no_depth_5c_usd: $ref: '#/components/schemas/Decimal' imbalance: $ref: '#/components/schemas/Decimal' BookLevel: type: object additionalProperties: false required: - price_usd - quantity - notional_usd properties: price_usd: $ref: '#/components/schemas/Decimal' description: Per contract that pays $1. quantity: $ref: '#/components/schemas/Decimal' description: >- Contracts (Kalshi) or outcome shares (Polymarket) resting at the price. notional_usd: $ref: '#/components/schemas/Decimal' description: Price times quantity. responses: BadRequest: description: Invalid parameter or market. content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: invalid_parameter message: 'Invalid or unsupported query parameter: limit.' Unauthorized: description: Missing, invalid or revoked API key. headers: WWW-Authenticate: schema: type: string content: application/json: schema: $ref: '#/components/schemas/Error' example: error: code: api_key_required message: Send an API key in the X-API-Key header or as a Bearer token. TooManyRequests: description: Rate limit or daily quota exceeded. headers: Retry-After: description: Seconds until the limit resets. schema: type: integer content: application/json: schema: $ref: '#/components/schemas/Error' Error: description: Any other error. content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: apiKey: type: apiKey in: header name: X-API-Key bearer: type: http scheme: bearer description: The same API key sent as a Bearer token. ````