Exact BPE token counts for OpenAI-family encodings (o200k_base for GPT-4o/4

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x15459498e1191d8787c83177809bd54022fA18c4",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000",
    "maxTimeoutSeconds": 300
  }
]

{
  "bazaar": {
    "info": {
      "input": {
        "body": {
          "encoding": "o200k_base",
          "text": "The quick brown fox jumps over the lazy dog."
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "output": {
        "body": {
          "chars": "number",
          "encoding": "string",
          "models": "string — which model families use it",
          "results": "array (batch mode) — { tokens, chars, truncated? }; totalTokens",
          "tokens": "number",
          "truncated": "string (only when truncate given and exceeded)"
        },
        "bodyType": "json",
        "example": {
          "chars": 44,
          "encoding": "o200k_base",
          "models": "gpt-4o, gpt-4.1, gpt-5 family, o-series",
          "tokens": 10
        }
      }
    },
    "routeTemplate": "/tokens",
    "schema": {
      "properties": {
        "input": {
          "additionalProperties": false,
          "properties": {
            "body": {
              "additionalProperties": false,
              "properties": {
                "encoding": {
                  "description": "BPE encoding (default o200k_base).",
                  "enum": [
                    "o200k_base",
                    "cl100k_base"
                  ],
                  "type": "string"
                },
                "text": {
                  "description": "Text to count.",
                  "type": "string"
                },
                "texts": {
                  "description": "Batch of texts.",
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 100,
                  "type": "array"
                },
                "truncate": {
                  "description": "Token budget — when exceeded the response includes the text cut to this many tokens.",
                  "type": "integer"
                }
              },
              "type": "object"
            },
            "bodyType": {
              "enum": [
                "json"
              ],
              "type": "string"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method",
            "bodyType",
            "body"
          ],
          "type": "object"
        }
      }
    }
  }
}

curl "https://workbot1.oddsys.org/tokens"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://workbot1.oddsys.org/tokens");
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
res = httpx.get("https://workbot1.oddsys.org/tokens")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header