Compute mid price from bid/ask top-of-book levels

What it does

Compute mid price from bid/ask top-of-book levels. Call when you have L1 bid and ask and need a mid for marks. Returns mid, spread_abs, and spread_bps as deterministic JSON for $0.001 USDC via x402 on Base. First-party local math only—no RPC, live market feed, API keys, storage, or mediagen. Advisory only; the caller owns capital, risk, and production controls.

Tags: x402 · agents · local-first · micro-usdc · pay-per-call · bazaar · payment-identifier

Call contract

Method

POST

Input

json

Output

json

Last paid call

2026-10-08

{
  "ask": 100.2,
  "bid": 100
}

{
  "ask": 100.2,
  "bid": 100,
  "mid": 100.1,
  "schema": "delx/util-ob-mid-from-levels/v1",
  "spread_abs": 0.20000000000000284,
  "spread_bps": 19.980019980020266
}

Use with an agent

1. Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
2. Inspect. Fetch /resources/31129.json for the price and payment options.
3. Pay. Call GET https://api.delx.ai/api/v1/x402/ob-mid-from-levels. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
4. Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, Solana, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price

$0.001 / request

Protocol

x402 v2

Auth

No account or API key. Pay per request.

Networks

Base, Solana

Demand

3 calls · 3 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x9f8bd9875b3E0b632a24A3A7C73f7787175e73A2",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000",
    "amountUsd": 0.001,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x9f8bd9875b3E0b632a24A3A7C73f7787175e73A2",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000",
    "amountUsd": 0.001,
    "maxTimeoutSeconds": 300
  },
  {
    "scheme": "exact",
    "network": "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
    "payTo": "28heAMpFkeUJsL7o7apiK4oJwZWq2fUHinRwbgYYsemG",
    "asset": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
    "amount": "1000",
    "amountUsd": 0.001,
    "maxTimeoutSeconds": 300
  }
]

Schemas

{
  "additionalProperties": true,
  "description": "Bounded first-party JSON result; input is processed in memory and not retained.",
  "properties": {
    "ask": {
      "type": "number"
    },
    "bid": {
      "type": "number"
    },
    "mid": {
      "type": "number"
    },
    "schema": {
      "type": "string"
    },
    "spread_abs": {
      "type": "number"
    },
    "spread_bps": {
      "type": "number"
    }
  },
  "type": "object"
}

{
  "ask": 0,
  "bid": 0,
  "mid": 0,
  "schema": "string",
  "spread_abs": 0,
  "spread_bps": 0
}

Examples

curl -X POST 'https://api.delx.ai/api/v1/x402/ob-mid-from-levels' -H 'Content-Type: application/json' --data '{"ask":100.2,"bid":100}'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

const res = await fetch("https://api.delx.ai/api/v1/x402/ob-mid-from-levels", {
  "method": "POST",
  "headers": {
    "content-type": "application/json"
  },
  "body": "{\"ask\":100.2,\"bid\":100}"
});
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

import httpx
import json
res = httpx.request("POST", "https://api.delx.ai/api/v1/x402/ob-mid-from-levels", json=json.loads("{\"ask\":100.2,\"bid\":100}"))
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider

api.delx.ai

Endpoint

https://api.delx.ai/api/v1/x402/ob-mid-from-levels

Machine-readable

/resources/31129.json