Preflight (Dry Run)

Preflight answers “what would actually happen if I called this paid endpoint right now?” It runs the same wallet selection, caps, and fundability checks as a real call, but performs no on-chain transfer, no upstream call, and no settlement. Use it before high-cost or batched calls so an agent can make a budget decision without probing with real money.

Two ways to preflight

Add the dry-run header to any paid route:

curl -s "https://gateway.apiosk.com/weather/current?city=Amsterdam" \
  -H "X-Apiosk-Connect-Token: $APIOSK_CONNECT_TOKEN" \
  -H "X-Apiosk-Dry-Run: 1"

Or call the dedicated route with the same auth headers:

curl -s -X POST https://gateway.apiosk.com/v1/apis/weather/preflight \
  -H "X-Apiosk-Connect-Token: $APIOSK_CONNECT_TOKEN"

Both return the same verdict. The response is marked with X-Apiosk-Dry-Run: true and is never cached.

The verdict

{
  "slug": "weather",
  "operation": "/current",
  "method": "GET",
  "price_listed_usdc": 0.06,
  "rail": "x402",
  "wallet_to_use": "0x1234…abcd",
  "would_succeed": true,
  "reason_if_not": null,
  "spent_after": {
    "wallet_address": "0x1234…abcd",
    "wallet_spent_today_usdc": 0.42,
    "wallet_day_cap_usdc": 25,
    "sepa_spent_today_eur": 0,
    "sepa_day_cap_eur": null
  },
  "wallet_selection_strategy": "first_authorized_wallet_passing_caps_and_onchain_can_settle"
}

Field	Meaning
`would_succeed`	Whether a real call would settle right now
`reason_if_not`	Human-readable reason when `would_succeed` is `false`
`rail`	`x402`, `sepa`, `credits`, `free`, or `unauthorized`
`price_listed_usdc`	Authorized gross price for the operation
`wallet_to_use`	The wallet the gateway would select (x402 rail)
`spent_after`	Projected daily spend and caps after this call, per rail
`wallet_selection_strategy`	How the gateway picks a wallet

Preflight models the x402 and SEPA rails; a real call may still settle over credits when preflight reports x402/sepa. Pin a rail with X-Apiosk-Rail (x402 or sepa) to test one path in isolation.

When to preflight

Before any call above ~$0.10, or a batch of more than five calls to one slug.
After a budget or mandate change, to confirm the buyer is still ready.
Instead of a real call when you only need to learn the price, combine with GET /v1/apis/{slug}.

Gateway skill: /guides/gateway-skill
Payment options: /guides/payment-options
Errors and retries: /guides/errors-and-retries

​Preflight (Dry Run)

​Two ways to preflight

​The verdict

​When to preflight

​Related links

Preflight (Dry Run)

Two ways to preflight

The verdict

When to preflight

Related links