Overview
Which transmission facilities bound in NYISO's day-ahead market and what each one cost, one row per interval and constraint. 527,082 rows, 2015-01 to the next delivery day. Columns: event_time, constraint_name, shadow_price_usd_mwh, plus contingency. The shadow price is the marginal cost of the binding limit — what the market would have saved from one more megawatt of capability on that element. This is the table that answers WHY congestion appeared; a price spread between two locations shows that they separated but not which facility separated them.
Use with MCP
This table is readable two ways, over the same guarded boundary. Over HTTP: POST /api/v1/datasets/nyiso_constraints_da/query, described in the API reference. Or from an MCP client: connect a market below, then use search_data or describe_data to load its query contract before calling query_data.
Schema4
event_timeDateTime64(6, 'UTC')constraint_nameLowCardinality(String)contingencyLowCardinality(String)shadow_price_usd_mwhNullable(Float64)Sample rows
| event_time | constraint_name | contingency | shadow_price_usd_mwh |
|---|---|---|---|
| 2026-08-27 03:00:00.000000 | SCH - PJ - NY | BASE CASE | 1.85 |
| 2026-08-27 03:00:00.000000 | SCH - OH - NY | BASE CASE | 0.37 |
| 2026-08-27 03:00:00.000000 | SPRNBRK 345 UNIONHBS 345 1 | BASE CASE | 2.11 |
| 2026-08-27 03:00:00.000000 | SCH - NE - NY | BASE CASE | -2.86 |
| 2026-08-27 03:00:00.000000 | DUNWODIE 345 SHORE_RD 345 1 | SIN:ACAD M29& TR1+8 & PAR 1+8 | 4.17 |
| 2026-08-27 02:00:00.000000 | SCH - PJ - NY | BASE CASE | 3.14 |
| 2026-08-27 01:00:00.000000 | SPRNBRK 345 UNIONHBS 345 1 | BASE CASE | 0.78 |
| 2026-08-27 01:00:00.000000 | ELWOOD 69 PULASKLI 69 1 | TWR:HOLBROOK 880 & 882 | 0.05 |
| 2026-08-27 01:00:00.000000 | DUNWODIE 345 SHORE_RD 345 1 | SIN:ACAD M29& TR1+8 & PAR 1+8 | 1.56 |
| 2026-08-27 01:00:00.000000 | HQCP ACTIVE DNI | ACTIVE DNI | -0.31 |
| 2026-08-27 00:00:00.000000 | HQTL ACTIVE DNI | ACTIVE DNI | -0.75 |
| 2026-08-27 00:00:00.000000 | ELWOOD 69 PULASKLI 69 1 | TWR:HOLBROOK 880 & 882 | 24.97 |
| 2026-08-27 00:00:00.000000 | SPRNBRK 345 UNIONHBS 345 1 | BASE CASE | 2.97 |
| 2026-08-27 00:00:00.000000 | NYCA ACTIVE DNI | ACTIVE DNI | -0.13 |
| 2026-08-27 00:00:00.000000 | DUNWODIE 345 SHORE_RD 345 1 | SIN:ACAD M29& TR1+8 & PAR 1+8 | 5.86 |
| 2026-08-27 00:00:00.000000 | PILGRIM 138 PILGRIM 138 1 | TWR:HOLBROOK 880 & 882 | -7.15 |
| 2026-08-27 00:00:00.000000 | E13THSTA 345 FARRAGUT 345 1 | BASE CASE | 0.06 |
| 2026-08-26 23:00:00.000000 | ELWOOD 69 PULASKLI 69 1 | TWR:HOLBROOK 880 & 882 | 81.18 |
| 2026-08-26 23:00:00.000000 | PILGRIM 138 PILGRIM 138 1 | TWR:HOLBROOK 880 & 882 | -23.29 |
| 2026-08-26 23:00:00.000000 | DUNWODIE 345 SHORE_RD 345 1 | SIN:ACAD M29& TR1+8 & PAR 1+8 | 7.13 |
| 2026-08-26 23:00:00.000000 | E13THSTA 345 FARRAGUT 345 1 | BASE CASE | 0.06 |
| 2026-08-26 23:00:00.000000 | SPRNBRK 345 UNIONHBS 345 1 | BASE CASE | 3.61 |
| 2026-08-26 22:00:00.000000 | ELWOOD 69 PULASKLI 69 1 | TWR:HOLBROOK 880 & 882 | 200 |
| 2026-08-26 22:00:00.000000 | SPRNBRK 345 UNIONHBS 345 1 | BASE CASE | 2.15 |
| 2026-08-26 22:00:00.000000 | NYCA ACTIVE DNI | ACTIVE DNI | 0.98 |