> ## Documentation Index
> Fetch the complete documentation index at: https://docs.echozero.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Core objects & glossary

> Agents, strategies, signals, subscribers, and the terms you will see across the API.

EchoZero uses a few core objects. This page defines them and how they relate.

## Entity model

```mermaid theme={null}
erDiagram
  Developer ||--o{ Agent : publishes
  Agent ||--o{ Signal : receives
  Signal ||--o{ Trade : may_execute
  User ||--o{ Subscription : holds
  Subscription }o--|| Agent : follows
  Agent ||--o| Strategy : may_use
```

| Object               | What it is                                                                                                                                                |
| -------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Developer**        | Registered builder with API keys, Stripe Connect, and payout rails                                                                                        |
| **Agent**            | Marketplace listing that receives signals and fans out to subscribers                                                                                     |
| **Strategy**         | Automated trading bot configuration (risk rules, conditions). In API copy, *strategy* and *trading bot* refer to the same resource (`/api/v1/strategies`) |
| **Signal**           | One inbound trade intent (`TradeSignal` row) from webhook, WebSocket, Telegram, Discord, or API                                                           |
| **Subscriber**       | End user with an active paid or free subscription to your agent                                                                                           |
| **Position / trade** | Executed buy/sell row tied to a subscriber wallet                                                                                                         |
| **Success fee**      | Percent of profitable trade notional charged to subscribers on the success-fee model                                                                      |

## Agent vs strategy

* **Agent** = marketplace persona + signal ingress + subscriber graph.
* **Strategy** = bot logic for automated trading on EchoZero (conditions, risk management, pause/play).

Signal-group and webhook agents focus on **ingress + fan-out**. Strategies are optional automation layers subscribers can also run.

## Glossary

| Term                | Meaning                                                                         |
| ------------------- | ------------------------------------------------------------------------------- |
| `positionRef`       | `signalId` or entry `idempotencyKey` for lifecycle events (sell, amend, cancel) |
| `idempotencyKey`    | Stable dedupe key; **always send on every signal** for replay protection        |
| `betaStatus`        | `pending-review` → `beta` → `public` (or `rejected`)                            |
| `signalSourceKind`  | `webhook` (HTTP ingress) or `signal_group` (Telegram/Discord)                   |
| `ez_live_` / `ezs_` | API key id / secret (REST HMAC)                                                 |
| `ezw_`              | Per-agent inbound webhook signing secret                                        |
| Virtual mode        | Paper trading with simulated wallet balances                                    |
| MCP session         | `mcp-session-id` header bound to the credential used at `initialize`            |
| REST HMAC           | `x-signature` + `x-timestamp` (ms, method, path, body)                          |
| Inbound HMAC        | `X-EZ-Signature` + `X-EZ-Timestamp` (seconds, canonical JSON)                   |
| Outbound HMAC       | `x-echozero-signature` on `signal.execution` callbacks                          |

## Credential cheat sheet

See the full [Authentication guide](/guides/authentication) for when to use each credential type.