Simmer Preflight

Run client.preflight() before every real-money trade. One call returns:

• Who you are: agent ID, tier, venue resolved from your API key context
• Which wallet will sign: execution wallet, deposit wallet, signer mode (OWS / external key / managed)
• Spendable balance: venue-specific USDC or $SIM balance from the briefing
• Open exposure: sum of current_value across your existing positions (real venues only for USD cap)
• Cap check: whether planned_amount + open_exposure_total exceeds your exposure_cap_usd
• Risk alerts: any briefing risk signals (concentration, expiry, reliability)
• ok_to_trade: a single boolean — True if no blockers

When to use

Call preflight before every automated trade, especially:

• Before the first real-money order of a run
• Before scaling into a position beyond your initial size
• When your heartbeat wakes up after a long sleep (state may have changed)

Do not call it on every polling tick — it makes 3 API calls. Once per trade intent is correct.

Call it

from simmer_sdk import SimmerClient

client = SimmerClient.from_env(venue="polymarket")

result = client.preflight(
    venue="polymarket",       # venue to check (defaults to client.venue)
    planned_amount=5.0,       # USDC you plan to spend on this trade
    exposure_cap_usd=100.0,   # your total cross-venue exposure limit
)

if not result.ok_to_trade:
    print(f"Preflight blocked: {result.blockers}")
    # e.g. ["EXPOSURE_CAP_EXCEEDED"]
    return

# Log for audit
ledger.record({
    "preflight_id": result.client_preflight_id,
    "ok": result.ok_to_trade,
    "exposure_before": result.open_exposure_total,
    "planned": result.planned_amount,
})

Result fields

Blocker codes (v0)

Blockers are additive — all blocking conditions are reported, not just the first.

Per-agent caller (Elite OWS)

For per-agent API keys, execution_wallet returns the per-agent OWS EOA — not the parent user's wallet. This is the SIM-2130 identity guarantee: the preflight returns the wallet that will actually sign the trade.

result = client.preflight(venue="polymarket", planned_amount=5, exposure_cap_usd=100)
print(result.execution_wallet)   # 0xYourAgentOWS... (not parent user's wallet)
print(result.deposit_wallet)     # 0xYourAgentDW... (per-agent DW if activated)

Exposure calculation

open_exposure_total sums current_value from /api/sdk/positions:

• For real venues (polymarket, kalshi): sums non-sim positions in USDC.
• For sim venue: sums sim positions in $SIM.

$SIM positions are never included in a USD cap check — they use virtual currency.

warnings[] vs blockers[]

blockers stop trading. warnings are informational — common examples:

• briefing_fetch_failed: \x3Cerror> — balance / alerts unknown; check connectivity
• positions_fetch_failed: \x3Cerror> — exposure may be understated; check rate limits
• identity_fetch_failed: \x3Cerror> — agent ID / tier unknown; API key may be invalid

If you see warnings, log them. Fetch failures on individual endpoints are gracefully handled — preflight returns best-effort data rather than throwing.

Pre-trade pattern (cookbook)

import os
from simmer_sdk import SimmerClient

EXPOSURE_CAP = float(os.environ.get("EXPOSURE_CAP_USD", "100"))

client = SimmerClient.from_env(venue="polymarket")

def safe_trade(market_id: str, side: str, amount: float):
    pf = client.preflight(
        venue="polymarket",
        planned_amount=amount,
        exposure_cap_usd=EXPOSURE_CAP,
    )
    if not pf.ok_to_trade:
        print(f"Preflight blocked ({pf.blockers}), skipping trade")
        return None
    if pf.warnings:
        print(f"Preflight warnings: {pf.warnings}")

    # Log preflight before order submission
    print(f"Preflight OK — id={pf.client_preflight_id} "
          f"exposure={pf.open_exposure_total:.2f}+{amount:.2f}/{EXPOSURE_CAP}")

    return client.trade(market_id=market_id, side=side, amount=amount)

Cadence

Call once per trade intent — not on every poll cycle. The preflight makes 3 API calls (/agents/me, /briefing, /positions), each counting toward your rate limits.

Scope

Preflight is read-only. It never signs, trades, redeems, or mutates settings. It is safe to call in any context including paper-trading mode (positions will reflect simulated holdings).

v0 limitations

• gas_balance is always None — on-chain RPC not available in the SDK client. Use the dashboard to verify POL / SOL balance.
• INSUFFICIENT_GAS is only detected if the briefing risk_alerts mention gas explicitly — not from an on-chain query.
• Server-side preflight_id (stable, storable) deferred to v1.
• MCP tool exposure deferred to v1.

Links

• API reference: docs.simmer.markets/api/preflight
• Wallet cohort guide: docs.simmer.markets/wallets