PJM · Pricing
PJM real-time constraint marginal values
PJM's settled record of every transmission constraint that bound in the real-time market, five minutes at a time, with its contingency, shadow price (negative, in PJM's convention), penalty factor and limit control percentage. Posted about three days late, on business days.
pjm-rt-marginal-valueevery 5 min, posted ~3 days late · 5m rows60 entitiesWhat is in it
- Updates
- every 5 min, posted ~3 days late · 5m rows
- Entities
- 60 entities — APSOUTH, BED-BLA…
- Source timezone
- US Eastern — every timestamp Dryos serves is UTC
- Coverage
- 6 September 2026 to now
- Rows held
- 8,449
- Primary key
- iso, constraint_name, contingency, interval_start_utc
What it measures
Every value, its unit, and what the source means by it.
- Marginal value$/MWh
The constraint's settled shadow price for the interval; negative in PJM's convention.
shadow_price
Columns
Exactly what a request answers with, read from the API rather than written here.
| Column | Type | Description |
|---|---|---|
| interval_start_utcrequired | timestamp | Start of the interval, UTC, read from PJM's own UTC column.e.g. 2026-09-09T12:30:00Z |
| isorequired | string | Publishing ISO.e.g. PJM |
| constraint_namerequired | string | The monitored facility as PJM names it — a line, transformer or interface.e.g. Chicago - Praxair3 138 kV l/o Wilton Center - Dumont 765 kV |
| contingencyrequired | string | The contingency the constraint bound for, as PJM names it (`ACTUAL` for the base case in the day-ahead market).e.g. Dumont-Wilton Center 765kV |
| shadow_pricerequired | number | The constraint's marginal value, $/MWh. Negative in PJM's convention, as on `pjm-binding-constraints`.e.g. -350.61 |
| penalty_factor | number | The transmission constraint penalty factor in force, $/MWh.e.g. 630.8 |
| limit_control_pct | number | The limit control percentage the dispatch applied, %.e.g. 100 |
| source_published_at_utc | timestamp | When PJM published the row, UTC. |
| collected_at_utcrequired | timestamp | When Dryos collected this row, UTC. Stamped by the platform, not the collector.e.g. 2026-09-09T12:35:12Z |
Read it
Public, read-only, no key and no sign-up. Relative times stay relative, so a URL keeps working.
The newest rows
curl "https://api.dryos.ai/v1/datasets/pjm-rt-marginal-value/query?node=APSOUTH&limit=12"The catalogue entry — every column, its type and the source
curl "https://api.dryos.ai/v1/datasets/pjm-rt-marginal-value"Hourly averages for the last day
curl "https://api.dryos.ai/v1/datasets/pjm-rt-marginal-value/query?node=APSOUTH&start=-24h&interval=1h&agg=avg"Full parameters — bucketing, aggregation, filters and search — are on the API reference.
Ask an agent
The same stream through the Model Context Protocol, so Claude, ChatGPT, Cursor or any MCP client can query it directly.
claude mcp add --transport http dryos https://api.dryos.ai/mcpThen ask:
What has Marginal value been at APSOUTH over the last 24 hours, and when did it peak?
Setup for every client is on the MCP server page.
Changes to this collector
A change in the collector is a change in the data. Anyone reading a step in a series is owed the day it moved under them.
- 2026-09-13
First collected, from PJM Data Miner 2.
PJM's settled shadow prices, kept by PJM indefinitely. Reconciled against live responses on 2026-09-13.
How this stream is checked
- Pulled straight from PJM Data Miner 2 · rt_marginal_value — no reseller in between — and compared against that file before it is served.
- Null means the source did not report it — never zero.
- A reading lands every 5 min, posted ~3 days late; the interval timestamp is the start of the interval, in UTC.
- PJM's Eastern Prevailing Time observes daylight saving; its rows carry UTC as well. Every timestamp Dryos serves is UTC.
Related streams
- PJM real-time LMPPJM
Unverified five-minute prices at PJM's 12 trading hubs, 22 transmission zones, 7 interfaces and every other aggregate pricing node, with the congestion and loss components, about four minutes after the interval starts.
every 5 min · 5m rows482 entitiespjm-realtime-lmp - PJM real-time hourly LMPPJM
PJM's own hourly integration of its unverified real-time prices at the 12 trading hubs, 22 transmission zones, 7 interfaces and every other aggregate, with the congestion and loss components, posted for the previous hour.
hourly, for the hour before · 1h rows482 entitiespjm-realtime-lmp-hourly - PJM real-time LMPs by busPJM
Unverified five-minute prices at every one of PJM's 13,967 electrical buses — generator, load and external — with the congestion and loss components.
every 5 min · 5m rows13,967 entitiespjm-rt-lmp-bus - PJM day-ahead LMPPJM
Hourly day-ahead prices at PJM's 482 aggregate pricing nodes — hubs, zones, interfaces, EHV and residual aggregates — with the energy, congestion and loss components as PJM publishes them, posted for the whole of tomorrow between 12:00 and 13:30 Eastern.
daily, ~12:30 ET · 1h rows482 entitiespjm-dam-lmp - PJM day-ahead LMPs by busPJM
Hourly day-ahead prices at every one of PJM's 13,967 electrical buses, with the energy, congestion and loss components as PJM publishes them.
daily, ~12:30 ET · 1h rows13,967 entitiespjm-dam-lmp-bus - PJM binding constraintsPJM
Every transmission constraint the real-time dispatch was up against, five minutes at a time, with the contingency it bound for and its shadow price (negative, in PJM's convention).
every 5 min, when bound · 5m rows60 entitiespjm-binding-constraints