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Developers / REPLAY / One session's closing measurements
Markdown copyOne session's closing measurements
FirmTape's derived closing summary of one finished session: open, close, high, low, the zero-gamma flip and its crossings, the walls, the net-gamma percentile, ATM IV. No key.
GET/api/session/{day}
Plan FreeNo keyVersion 1.1.0Since 2026-09-01
This endpoint serves
Parameters
| Name | What it does | Default | Error |
|---|---|---|---|
| dayrequiredpath · string | Finished SPX trading day |
Response
Public derived session summary
| Field | Meaning | Unit |
|---|---|---|
| daystring | ||
| urlstring | ||
| previous_daystring | null | ||
| next_daystring | null | ||
| opennumber | ||
| closenumber | ||
| highnumber | ||
| lownumber | ||
| vwap_closenumber | null | ||
| zero_gamma_flipnumber | null | ||
| call_resistancenumber | null | ||
| put_supportnumber | null | ||
| atm_iv_opennumber | null | ||
| net_gamma_percentilenumber | null | ||
| flip_crossingsinteger | ||
| sourcestring |
Errors
| Status | Code | What to do |
|---|---|---|
| 404 | Unknown, live or unavailable session. |
Every code: Errors.
Changes
- 2026-09-01 Added.
OpenAPI operation getArchivedSession in /docs/developers/openapi.json.
Measurements of dealer positioning, never a forecast or a trade call. This page is built from FirmTape's public contract, the same files the OpenAPI document is built from; the tests hold them against the route code. Markdown: /docs/developers/replay/session.md.