| Participant | The legal entity that is registered on the ETPA platform and authorised to trade. They hold a participant ID. |
| Individual | A user (person) within a Participant, who logs into the system and executes actions (subject to roles). |
| API Key | A unique token/header used to authenticate API requests. Required for accessing the API endpoints. |
| Environment (ACC / PROD) | There are separate “acceptance” (ACC/testing) and “production” (PROD) environments for the API. Use ACC first, then switch to PROD after testing. |
| Order | A request submitted by a Participant to buy or sell electricity in one of the markets (Intraday, Ex-Post, XBID) via the API. |
| Trade | A matched order (or execution) on the platform. Trades result from orders being approved/matched. |
| Wallet / Power Wallet | The virtual financial account tied to a Participant that holds funds to cover trading activity (deposits & withdrawals). |
| Delivery Area | Geographic/market zone identifier for electricity delivery (e.g., NL-TTN, DE-50HzT etc.). Used in orders/trades. |
| Product / Time-block | The product being traded (e.g., Hour, Half-Hour, Quarter) and the time-block for which the electricity is delivered. |
| Pagination | The mechanism by which the API returns large sets of records in pages (to manage performance). Different versions (v1.0 vs v2.0) have different pagination methods. |
| SSE (Server-Sent Events) | A streaming mechanism where the client subscribes to a channel to receive real-time updates (e.g., orderbook updates) rather than polling repeatedly. |
| On-Hold Order | A special status of an order which is held and not yet placed in the active order book until further action. |
| XBID | The cross-border intraday market (common order book) product category supported by ETPA. |
| GOPACS | The congestion management market segment (trading spread buckets, etc.). |
| Ex-Post | The day‐after trading product: trading after delivery of contracts. |
| Limit (Trading Limit) | The amount (MW per quarter, or monetary amount) that a Participant is allowed to trade in a certain market product. Limits are set during KYC and before trading. |
| TSO (Transmission System Operator) | is the company responsible for operating and maintaining the high-voltage electricity grid, ensuring that supply and demand are balanced in real time, and coordinating with BRPs to manage any deviations. |
| BRP (Balance Responsible Party) | (Previously known as “PV-party” in the TenneT terminology but changed later on to BRP). BRP is The company registered with the TSO that takes responsibility for keeping electricity supply and demand balanced for its portfolio, including the trades of ISVs, and settles any differences on the imbalance market. |
| ISV (Indirectly Settled Vendor) | A market participant that trades electricity but relies on a BRP to handle grid balancing and settlement. |
| DSO (Distribution System Operator) | Is the grid operator responsible for local network access and metering data, enabling market participants (like BRPs and suppliers) to trade and settle electricity at the distribution level. |