Trading Engine

Overview

Milo's trading engine executes swaps on Solana through Jupiter, the leading DEX aggregator. Every trade — whether placed manually or triggered by Milo's auto-trader — is routed through Jupiter to get the best price across all Solana liquidity sources.

There is no centralized order book. No custodial exchange. Your tokens stay in your wallet until the moment a swap settles on-chain.

For the full endpoint reference, see the Partner API docs.

Architecture

┌──────────┐     ┌──────────────┐     ┌──────────┐     ┌──────────┐
│  Partner  │────►│  Milo Order  │────►│ Jupiter  │────►│  Solana  │
│   API     │     │   Engine     │     │ Routing  │     │   Chain  │
└──────────┘     └──────────────┘     └──────────┘     └──────────┘
                        │                                     │
                  ┌─────┴──────┐                              │
                  │  Turnkey   │◄─────────────────────────────┘
                  │  Signer    │     transaction confirmation
                  └────────────┘

1. You create an order via the Partner API (or Milo's auto-trader creates one)

2. The engine monitors trigger conditions (price thresholds)

3. When the trigger fires, the engine requests a quote from Jupiter

4. Jupiter finds the best route across all Solana DEXs and AMMs

5. The transaction is signed via Turnkey (non-custodial — your keys, your wallet)

6. The signed transaction is submitted to Solana for on-chain settlement

7. Order status updates to fulfilled with the transaction signature

Fully Decentralized

Milo never takes custody of your funds.

• Non-custodial wallets — Each user gets a Solana wallet powered by Turnkey. The signing key belongs to you, not Milo. Milo receives delegated permission to execute trades on your behalf.

• On-chain settlement — Every swap is a Solana transaction. You can verify it on any block explorer.

• Jupiter routing — Trades are routed through Jupiter's aggregator, which splits across Raydium, Orca, Meteora, Phoenix, and dozens of other Solana DEXs to find the best price.

• No counterparty risk — Milo doesn't hold your tokens, doesn't run an order book, and doesn't match trades internally. Every trade settles peer-to-pool on Solana.

---

Order Types

All orders are created through POST /api/v1/wallets/{walletId}/orders. The order type is determined by the combination of type, trigger, and amount in the payload. See the Partner API — Orders section for the full endpoint reference.

Market Order

Execute immediately at the best available price. Uses the trigger { "operator": "gte", "value": 0 } — a condition that is always true.

{
  "type": "buy",
  "amount": { "type": "absolute_usd", "amount": 100 },
  "trigger": { "type": "absolute", "trigger": "price", "operator": "gte", "value": 0 },
  "execution": {}
}

Limit Order

Execute when the token reaches a specific price.

Buy when price drops to $0.50:

{
  "type": "buy",
  "amount": { "type": "absolute_usd", "amount": 100 },
  "trigger": { "type": "absolute", "trigger": "price", "operator": "lte", "value": 0.50 },
  "execution": {}
}

Sell when price rises to $2.00:

{
  "type": "sell",
  "amount": { "type": "relative", "percentage": 100 },
  "trigger": { "type": "absolute", "trigger": "price", "operator": "gte", "value": 2.00 },
  "execution": {}
}

Stop-Loss

Sell when the price drops by a percentage. Uses a relative trigger with the drop operator.

{
  "type": "sell",
  "amount": { "type": "relative", "percentage": 100 },
  "trigger": { "type": "relative", "trigger": "price", "operator": "drop", "value": 15 },
  "execution": {}
}

Sells 100% of the position if the price drops 15%.

Take-Profit

Sell when the price rises by a percentage. Uses a relative trigger with the rise operator.

{
  "type": "sell",
  "amount": { "type": "relative", "percentage": 50 },
  "trigger": { "type": "relative", "trigger": "price", "operator": "rise", "value": 30 },
  "execution": {}
}

Sells 50% of the position when the price rises 30%.

TP/SL Ladders

Create a buy order with multiple take-profit and stop-loss levels attached. Pass takeProfits and stopLosses arrays alongside the main order payload — the engine creates them as draft dependant sell orders linked to the parent.

{
  "takeProfits": [
    { "percentage": 25, "profitPercentage": 20 },
    { "percentage": 25, "profitPercentage": 50 },
    { "percentage": 50, "profitPercentage": 100 }
  ],
  "stopLosses": [
    { "percentage": 100, "lossPercentage": 15 }
  ]
}

This example:

• Sells 25% at +20% profit

• Sells 25% at +50% profit

• Sells 50% at +100% profit

• Sells 100% if price drops 15% (stop-loss)

Trailing Stop

Coming Soon — A stop-loss that moves up as the price rises, locking in gains while protecting against reversals. The stop distance will be configurable as a percentage.

DCA (Dollar-Cost Averaging)

Coming Soon — Split a large buy into smaller orders executed at regular intervals. Configure total amount, number of splits, and interval duration to reduce the impact of volatility on entry price.

TWAP (Time-Weighted Average Price)

Coming Soon — Execute a large order in equal slices over a time window to minimize market impact. Optimized for execution quality on larger positions.

---

Triggers

Every order has a trigger that defines when it executes.

Absolute

Fire when the token price hits a specific USD value.

Operator	Meaning	Use case
gte	Price >= value	Market order (value: 0), sell above target
lte	Price <= value	Limit buy at dip

Relative

Fire when the token price moves by a percentage from a reference point.

Operator	Meaning	Use case
rise	Price rose by X%	Take-profit
drop	Price dropped by X% (max 100)	Stop-loss

---

Amount Types

Type	Field	Description	Available for
absolute	amount	Raw token amount (base units)	Buy, Sell
absolute_usd	amount	USD equivalent	Buy, Sell
relative	percentage	% of current position (1-100)	Sell only

---

Execution Options

Fine-tune how your order executes on-chain. All fields are optional — sensible defaults are applied.

Field	Type	Default	Description
slippagePercentage	number	3%	Max allowable slippage (0-100)
priorityFee	number	auto	Priority fee in SOL lamports for faster block inclusion
platformFeeBps	number	90-100 bps	Milo platform fee in basis points

Higher slippage tolerance increases fill probability for volatile tokens. Higher priority fees get your transaction included faster by Solana validators.

---

Order Lifecycle

draft ──► active ──► fulfilling ──► fulfilled
                │
                ├──► paused ──► active
                │
                └──► error / expired

archived (deleted by user)

Status	Description
draft	Created but not monitoring. TP/SL dependants start here.
active	Engine is monitoring the trigger condition
fulfilling	Trigger fired, swap is executing on-chain
fulfilled	Swap confirmed on Solana
paused	Temporarily stopped — resume with the activate endpoint
error	Execution failed after retries
archived	Soft-deleted by user

You can manage order state through the Partner API:

• Pause — POST /api/v1/users/{userId}/orders/{orderId}/pause

• Resume — POST /api/v1/users/{userId}/orders/{orderId}/activate

• Delete — DELETE /api/v1/users/{userId}/orders/{orderId}

• List — GET /api/v1/users/{userId}/orders

• Details — GET /api/v1/users/{userId}/orders/{orderId}

See Partner API — Orders for full details.

---

Error Handling

When an order fails, the executionSummary field contains the reason. Common errors:

Error	Meaning
no_route_found	Jupiter couldn't find a swap path — token may have no liquidity
not_enough_token_balance	Insufficient tokens in wallet to fill the sell
not_enough_sol	Not enough SOL to cover transaction fees
slippage_too_low	Price moved beyond your slippage tolerance during execution
swap_not_supported	Token pair cannot be swapped
network_error	Solana RPC or network issue

Failed orders are retried with exponential backoff (up to 5 attempts). If all retries fail, the order moves to error status.

---

Roadmap

Feature	Status
Market orders	Live
Limit orders (absolute price triggers)	Live
Stop-loss (relative % drop)	Live
Take-profit (relative % rise)	Live
TP/SL ladders (multi-level dependants)	Live
Order pause / resume / delete	Live
Position close / close-all	Live
Trailing stop	Coming soon
DCA (dollar-cost averaging)	Coming soon
TWAP (time-weighted average price)	Coming soon
Conditional chains (if X then Y)	Planned