> ## Documentation Index > Fetch the complete documentation index at: https://docs.gammaflip.io/llms.txt > Use this file to discover all available pages before exploring further. # Capture timestamps of a session date > The capture times (ISO 8601 UTC) of one session date, oldest first. The session date is the UTC date for crypto and the New York trading date for TradFi. Counts as 1 request. ## OpenAPI ````yaml /openapi.yaml get /history/timestamps/{exchange}/{coin} openapi: 3.1.0 info: title: GammaFlip GEX API version: 1.0.0 description: > Programmatic access to Gamma Exposure (GEX) data for crypto options (Bybit, Deribit, OKX, Derive) and US options (the `tradfi` exchange). API access is a plan entitlement (`api_access`). The trial includes it (50 requests/day); other plans with API access get 500 requests/day. Only `/gex/...`, `/levels/...` and the `/history/...` query endpoints count against the quota; `/exchanges`, `/coins`, `/expirations/...`, `/me` and `/history/coverage` are free. History file downloads use a separate daily bucket of file credits (trial 20, other plans 200). A `429` carries no `Retry-After` header: use `X-RateLimit-Reset`, `X-History-Files-Reset` or `/me`. All GEX values are USD per 1% move of the underlying. Field definitions: https://docs.gammaflip.io/data-dictionary contact: name: GammaFlip Support email: admin@gammaflip.io url: https://gammaflip.io servers: - url: https://api.gammaflip.io/api/v1 description: Production security: - ApiKeyAuth: [] paths: /history/timestamps/{exchange}/{coin}: get: tags: - History summary: Capture timestamps of a session date description: > The capture times (ISO 8601 UTC) of one session date, oldest first. The session date is the UTC date for crypto and the New York trading date for TradFi. Counts as 1 request. operationId: getHistoryTimestamps parameters: - $ref: '#/components/parameters/HistoryExchange' - $ref: '#/components/parameters/Coin' - name: date in: query required: true description: Session date, `YYYY-MM-DD`. schema: type: string format: date example: '2026-10-05' responses: '200': description: Capture timestamps content: application/json: schema: type: object required: - data - meta properties: data: type: array items: type: string format: date-time meta: $ref: '#/components/schemas/HistoryMeta' '400': $ref: '#/components/responses/HistoryNotAvailable' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '429': $ref: '#/components/responses/RateLimited' components: parameters: HistoryExchange: name: exchange in: path required: true description: > `bybit`, `deribit`, `okx`, `derive`, `combined` or `tradfi`. `all` and `combined` with a TradFi ticker resolve to `tradfi`. Venue subsets such as `deribit+derive` have no history: `400 history_not_available`. schema: type: string examples: - deribit - combined - tradfi Coin: name: coin in: path required: true description: >- Symbol (case-insensitive), for example `BTC` or `QQQ`. Use `/coins` for the list. schema: type: string example: BTC schemas: HistoryMeta: type: object properties: timestamp: type: string format: date-time exchange: type: string description: As requested (lowercased). example: tradfi coin: type: string example: QQQ symbol: type: string example: QQQ exchange_resolved: type: string example: tradfi market: type: string enum: - crypto - tradfi units: type: string example: USD per 1% move of the underlying docs_url: type: string example: https://docs.gammaflip.io/data-dictionary granularity: type: string enum: - 15m - 1h - close description: '`/history/levels` only.' start: type: string format: date-time description: '`/history/levels` only: the window start as applied.' end: type: string format: date-time description: '`/history/levels` only: the window end (exclusive) as applied.' next_cursor: type: - string - 'null' description: >- `/history/levels` only: pass as `cursor` for the next page; `null` on the last page. session_date: type: string format: date description: '`/history/timestamps` only.' snapshot_at: type: string format: date-time description: '`/history/snapshot` only: the capture returned.' rate_limit: $ref: '#/components/schemas/RateLimit' RateLimit: type: object properties: limit: type: integer example: 500 remaining: type: integer example: 487 reset: type: string format: date-time example: '2026-04-15T00:00:00+00:00' Error: type: object description: > Standard error body. `error` is a stable slug safe to branch on; `message` is human-readable prose that may change and must not be parsed. Errors are never wrapped in the data/meta envelope used by successful responses. Some errors add hint fields. required: - error - message properties: error: type: string enum: - unauthorized - subscription_required - market_not_in_plan - rate_limit_exceeded - invalid_exchange - invalid_pair - invalid_expiration - invalid_param - no_data - unsupported_coin - market_unavailable - history_not_available - range_too_large - no_snapshot - no_file - files_unavailable - history_files_limit_exceeded - method_not_allowed example: invalid_exchange message: type: string example: Exchange 'kraken' is not available. current_tier: type: string description: With `subscription_required` and `market_not_in_plan`. example: trial valid_exchanges: type: array items: type: string description: With `invalid_exchange`, `invalid_pair` and `history_not_available`. example: - deribit - bybit - okx - derive - combined nearest_expirations: type: array items: type: string description: >- With `invalid_expiration`; up to five ISO dates closest to the request (the earliest five if the value is not a date). example: - '2026-10-17' - '2026-10-19' valid_values: type: array items: type: string description: >- With `invalid_param` for `view`, `granularity`, `file` and `compare`. example: - full - levels max_value: type: number description: With `invalid_param` for `range_pct`. example: 50 max_window_days: type: integer description: With `range_too_large`. example: 31 nearest_timestamps: type: array items: type: string format: date-time description: With `no_snapshot`; up to three capture times closest to `at`. example: - '2026-10-05T20:15:00Z' - '2026-10-05T13:45:00Z' market: type: string description: With `market_not_in_plan`; the market the requested coin belongs to. enum: - crypto - tradfi example: tradfi markets_in_plan: type: array items: type: string description: With `market_not_in_plan`. supported_crypto: type: array items: type: string description: >- With `unsupported_coin`; crypto coins listed by at least one exchange. example: - BTC - ETH - HYPE - SOL - XRP supported_tradfi: type: array items: type: string description: With `unsupported_coin`; US tickers we track. example: - QQQ - SPX - SPY rate_limit: allOf: - $ref: '#/components/schemas/RateLimit' description: >- With `rate_limit_exceeded` and `history_files_limit_exceeded`; mirrors the X-RateLimit-* headers. responses: HistoryNotAvailable: description: > `invalid_exchange`, `invalid_pair`, `invalid_param`, `history_not_available` (venue subset; with `valid_exchanges`) or `range_too_large` (with `max_window_days`). content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: > Missing or invalid credential, or a credential that does not resolve to a user. Both return `unauthorized`. content: application/json: schema: $ref: '#/components/schemas/Error' Forbidden: description: > `subscription_required` (the plan has no API access) or `market_not_in_plan` (the plan does not include the coin's market). content: application/json: schema: $ref: '#/components/schemas/Error' RateLimited: description: | Daily rate limit exceeded. No `Retry-After` header is sent: use `X-RateLimit-Reset` or `GET /me`. headers: X-RateLimit-Limit: schema: type: integer X-RateLimit-Remaining: schema: type: integer example: 0 X-RateLimit-Reset: schema: type: string format: date-time content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-Key description: | API key prefixed with `gex_sk_`. Create one in your [account dashboard](https://gammaflip.io/account). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.