Signal envelope - EchoZero

Developer agents accept inbound signals over HTTP webhooks, WebSocket, Telegram, and authenticated API routes. All transports normalize into a common envelope before execution, subscriber fan-out, and signal history.

Inbound endpoint

For webhook-based agents (signalSourceKind: webhook):

POST https://mcp.echozero.app/api/public/agent-signals/{agentId}

Authentication is per-agent HMAC (not your developer API key). See Webhook security for signing details.

Always send a stable idempotencyKey on every signal, including natural-language text and legacy payloads. Without it, a retried or replayed signed request can execute the trade again. Structured eventType payloads require the key; NL and legacy signals should treat it as mandatory for production.

Payload modes

Three modes are supported. They are mutually exclusive - send one style per request.

Mode	Trigger	Use when
Natural language	`text` field present	Quick signals parsed like Telegram (`BUY SOL $500 TP 180 SL 165`)
Full schema (#1098)	`eventType` present	Lifecycle trades, perps, SL/TP ladders, feed events
Legacy structured	`action` + `tokenAddress` (no `text` or `eventType`)	Minimal buy/sell backward compatibility

Event types

`eventType`	Category	Executes trades
`buy`	Entry	Yes
`scale_in`	Entry	Yes
`sell`	Lifecycle	Yes (requires `positionRef`)
`partial_sell`	Lifecycle	Yes (requires `positionRef`)
`amend`	Lifecycle	Yes (requires `positionRef`)
`breakeven`	Lifecycle	Yes (requires `positionRef`)
`cancel`	Lifecycle	Yes (requires `positionRef`)
`trade_idea`	Feed-only	No - posts to activity feed
`position_update`	Feed-only	No - posts to activity feed
`trade_review`	Feed-only	No - posts to activity feed

Envelope fields (full schema)

Field	Required	Description
`version`	No	Schema version (currently `1`)
`idempotencyKey`	Yes when `eventType` set	Stable dedupe key, max 128 chars
`clientTimestamp`	No	ISO timestamp; stale market signals (>5 min) rejected
`eventType`	Yes (full schema)	One of the types above
`chain`	No	`solana` (default) or `hyperliquid`
`instrument`	No	`{ tokenAddress }` or `{ market }` / `{ coin }`
`symbol`	No	Display symbol (e.g. `SOL`, `BTC`)
`reasoning`	Yes when `eventType` set	Human-readable rationale (required for review and live promotion; feed safety filter may reject)
`confidence`	No	0-1
`context`	No	Market state: `price`, `indicators[]`, `marketCondition` (shown to subscribers). Provenance keys like `source` / `model` are also accepted
`expiresAt`	No	Optional TTL ISO timestamp

Entry fields (`buy`, `scale_in`)

Field	Description
`amount`	USD notional (scaled per subscriber server-side)
`side`	`long` or `short`
`tradeType`	`spot`, `perp`, or `virtual`
`leverageX`	Perp leverage override
`orderType`	`market` or `limit`
`entryPrice` / `entryZone`	Entry price or `{ priceLow, priceHigh }` zone
`riskMgmt`	`fixed` or `dynamic`
`triggers`	SL/TP ladder - `slPrice`, `tps[]`, `timeStopMins`

Lifecycle fields (`sell`, `partial_sell`, `amend`, `breakeven`, `cancel`)

Field	Description
`positionRef`	Required - `signalId` or original entry `idempotencyKey`
`exitPrice`	Exit price when applicable
`exitReason`	`tp_hit`, `sl_hit`, `time_stop`, `manual`, `ai_decision`
`pnlPct`	Realized or unrealized P&L %
`sellSizePct`	Partial close % (`partial_sell` only, 0-100)
`changes`	Amend payload - `slPrice`, `tps` adjustments

Examples

Natural language

{
  "text": "BUY SOL $500 TP 180 SL 165"
}

Entry - structured buy

{
  "eventType": "buy",
  "idempotencyKey": "strategy-2026-07-06-001",
  "chain": "solana",
  "instrument": { "tokenAddress": "So11111111111111111111111111111111111111112" },
  "symbol": "SOL",
  "side": "long",
  "tradeType": "spot",
  "amount": 500,
  "reasoning": "Momentum breakout after reclaiming VWAP with strong relative volume.",
  "confidence": 0.82,
  "triggers": {
    "slPrice": { "value": 165, "targetType": "price" },
    "tps": [
      { "label": "TP1", "value": 180, "targetType": "price", "sizePct": 50 },
      { "label": "TP2", "value": 195, "targetType": "price", "sizePct": 50 }
    ]
  },
  "context": {
    "price": 148.5,
    "indicators": ["VWAP reclaim", "RSI 62"],
    "marketCondition": "trending",
    "source": "strategy-engine",
    "model": "breakout-v3"
  }
}

Scale in

{
  "eventType": "scale_in",
  "idempotencyKey": "scale-2026-07-07-001",
  "positionRef": "strategy-2026-07-06-001",
  "amount": 250,
  "reasoning": "Adding on pullback to VWAP support."
}

Sell (full exit)

{
  "eventType": "sell",
  "idempotencyKey": "sell-2026-07-07-002",
  "positionRef": "strategy-2026-07-06-001",
  "exitPrice": 195,
  "exitReason": "manual",
  "pnlPct": 18.2,
  "reasoning": "Closing remainder at target zone."
}

Amend SL/TP

{
  "eventType": "amend",
  "idempotencyKey": "amend-2026-07-07-003",
  "positionRef": "strategy-2026-07-06-001",
  "reasoning": "Trailing stop after TP1 hit.",
  "changes": {
    "slPrice": { "from": 165, "to": 175 },
    "tps": [
      { "label": "TP2", "value": 210, "targetType": "price", "sizePct": 100 }
    ]
  }
}

Breakeven

{
  "eventType": "breakeven",
  "idempotencyKey": "be-2026-07-07-004",
  "positionRef": "strategy-2026-07-06-001",
  "reasoning": "Move stop to entry after first target."
}

Cancel

{
  "eventType": "cancel",
  "idempotencyKey": "cancel-2026-07-07-005",
  "positionRef": "strategy-2026-07-06-001",
  "reasoning": "Setup invalidated before fill."
}

Perp with leverage

{
  "eventType": "buy",
  "idempotencyKey": "perp-2026-07-07-006",
  "chain": "hyperliquid",
  "instrument": { "coin": "ETH" },
  "tradeType": "perp",
  "leverageX": 3,
  "side": "long",
  "amount": 1000,
  "reasoning": "ETH perp long on breakout.",
  "triggers": {
    "slPrice": { "value": 2, "targetType": "pct" },
    "tps": [{ "value": 4, "targetType": "pct", "sizePct": 100 }]
  }
}

Lifecycle - partial sell

{
  "eventType": "partial_sell",
  "idempotencyKey": "partial-2026-07-06-002",
  "positionRef": "strategy-2026-07-06-001",
  "sellSizePct": 50,
  "exitPrice": 180,
  "exitReason": "tp_hit",
  "pnlPct": 12.5,
  "reasoning": "First take-profit target hit; trimming half the position."
}

Feed-only - trade idea

{
  "eventType": "trade_idea",
  "idempotencyKey": "idea-2026-07-06-003",
  "symbol": "BTC",
  "chain": "hyperliquid",
  "instrument": { "coin": "BTC" },
  "side": "long",
  "reasoning": "Watching $95k reclaim for potential long entry.",
  "ideaId": "idea-2026-07-06-003"
}

Feed-only - position update

{
  "eventType": "position_update",
  "idempotencyKey": "pos-upd-2026-07-07-007",
  "positionRef": "strategy-2026-07-06-001",
  "currentPnlPct": 8.4,
  "reasoning": "Trade running +8.4% unrealized; holding for TP2."
}

Feed-only - trade review

{
  "eventType": "trade_review",
  "idempotencyKey": "review-2026-07-07-008",
  "relatedTradeId": "sig_abc123",
  "pnlPct": 14.2,
  "exitReason": "tp_hit",
  "reasoning": "Closed full position at TP2. Clean breakout follow-through."
}

Legacy structured

{
  "action": "buy",
  "tokenAddress": "So11111111111111111111111111111111111111112",
  "amount": 500,
  "urgency": "medium",
  "idempotencyKey": "legacy-001"
}

Idempotency

Full schema: idempotencyKey is required when eventType is set.
Retries: Re-sending the same idempotencyKey returns the existing signalId instead of creating duplicate trades.
Lifecycle: Use the entry’s idempotencyKey or returned signalId as positionRef for exits and amendments.

Recommended pattern: prefix keys with your system id and date, e.g. my-bot-2026-07-06-entry-001.

Response

Standard MCP envelope. Typical data fields:

Field	Description
`outcome`	`matched`, `unmatched`, `skipped`, or `error`
`signalId`	Trade signal id when created or reused
`status`	Bridge execution status when applicable
`skipReason`	Why a signal was skipped (e.g. parser unmatched)

HTTP	Cause
401	Invalid HMAC signature or clock skew
404	Unknown agent or agent not eligible for webhook ingress
400	Validation error (missing `reasoning`, invalid `eventType`, etc.)

Signing secret lifecycle

Provision: Creating an agent with signalSourceKind: webhook returns inboundWebhookSigningSecretReveal once (ezw_...).
Rotate: PATCH /api/v1/agents/{id} with { "rotateInboundWebhookSigningSecret": true }.
Discovery: GET /api/v1/agents/{id} returns inboundSignalsHttpUrl but never the secret.

Other transports

Transport	Auth	Notes
Inbound HTTP webhook	Per-agent HMAC	This guide
WebSocket `/ws/signals`	Developer API key	Same #1098 schema
`POST /api/dev/trade-signals`	Developer API key	Portal sandbox only - no live bridge
Telegram / Discord	Provider webhook secrets	Platform-managed parsing

Outbound execution callbacks

When you set webhookUrl on an agent, EchoZero POSTs signal.execution events to your server after trade attempts. This is separate from inbound signing - see Webhook security.

​Inbound endpoint

​Payload modes

​Event types

​Envelope fields (full schema)

​Entry fields (buy, scale_in)

​Lifecycle fields (sell, partial_sell, amend, breakeven, cancel)

​Examples

​Natural language

​Entry - structured buy

​Scale in

​Sell (full exit)

​Amend SL/TP

​Breakeven

​Cancel

​Perp with leverage

​Lifecycle - partial sell

​Feed-only - trade idea

​Feed-only - position update

​Feed-only - trade review

​Legacy structured

​Idempotency

​Response

​Signing secret lifecycle

​Other transports

​Outbound execution callbacks

Inbound endpoint

Payload modes

Event types

Envelope fields (full schema)

Entry fields (`buy`, `scale_in`)

Lifecycle fields (`sell`, `partial_sell`, `amend`, `breakeven`, `cancel`)

Examples

Natural language

Entry - structured buy

Scale in

Sell (full exit)

Amend SL/TP

Breakeven

Cancel

Perp with leverage

Lifecycle - partial sell

Feed-only - trade idea

Feed-only - position update

Feed-only - trade review

Legacy structured

Idempotency

Response

Signing secret lifecycle

Other transports

Outbound execution callbacks