Verify you are on real Animica mainnet, and which chain id to sign with

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x5D17c40FD6b119dc6006C4Ab3C20a917FCaB2aCD",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "6000",
    "maxTimeoutSeconds": 60
  },
  {
    "scheme": "exact",
    "network": "animica:1",
    "payTo": "anim1zqpsmegc0qcvzjfukm89xs0zeu3eqyyyel7kelehuszvwfarqypky2gr946ga",
    "asset": "ANM",
    "amount": "65416484954",
    "maxTimeoutSeconds": 60
  }
]

{
  "animica": {
    "catalog": "https://animica.dev/.well-known/x402",
    "content_type": "application/json",
    "currency": "USDC",
    "description": "Verify you are on real Animica mainnet, and which chain id to sign with. Animica answers that question with TWO numbers: the native chain is id 1, while the EVM compatibility facade reports 149 (eth_chainId 0x95, net_version \"149\"). A wallet porting Ethereum tooling signs with the wrong one. Returns both, the disagreement named, plus genesis hash, fork id, policy hash and the built-in consensus checkpoints a light client pins against. All read live. No model.",
    "documentation": "https://animica.dev/x402#product-chain_identity",
    "name": "Animica chain identity and replay-protection check",
    "openapi": "https://animica.dev/x402/openapi.json",
    "price": "0.006000",
    "product": "chain_identity",
    "provider": "Animica",
    "terms": {
      "amount_atomic": "6000",
      "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "chain_id": 8453,
      "network": "eip155:8453",
      "pay_to": "0x5D17c40FD6b119dc6006C4Ab3C20a917FCaB2aCD",
      "scheme": "exact"
    },
    "x402_version": 2
  },
  "bazaar": {
    "discoverable": true,
    "info": {
      "input": {
        "body": {
          "expect_chain_id": 1,
          "expect_genesis_hash": "0xa0892158cf997c56e91d0aa12e60c36037dae34800a2b54111a8fa17ec88b7de"
        },
        "bodyType": "json",
        "method": "POST",
        "type": "http"
      },
      "output": {
        "type": "json"
      }
    },
    "schema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
        "input": {
          "properties": {
            "body": {
              "properties": {
                "expect_chain_id": {
                  "description": "the chain id you BELIEVE you are talking to. When given, the response carries an explicit matches_native / matches_evm_facade verdict instead of leaving you to compare two numbers yourself — which is the comparison people get wrong.",
                  "type": "integer"
                },
                "expect_genesis_hash": {
                  "description": "the genesis hash you have pinned (0x… 32 bytes). Compared byte-for-byte; a mismatch is reported as a hard failure, since it means this is not the chain you think it is.",
                  "type": "string"
                }
              },
              "type": "object"
            },
            "bodyType": {
              "enum": [
                "json"
              ],
              "type": "string"
            },
            "method": {
              "enum": [
                "POST"
              ],
              "type": "string"
            },
            "queryParams": {
              "properties": {
                "expect_chain_id": {
                  "description": "same as body.expect_chain_id for GET callers",
                  "type": "string"
                },
                "expect_genesis_hash": {
                  "description": "same as body.expect_genesis_hash for GET callers",
                  "type": "string"
                }
              },
              "type": "object"
            },
            "type": {
              "const": "http",
              "type": "string"
            }
          },
          "required": [
            "type",
            "method"
          ],
          "type": "object"
        },
        "output": {
          "properties": {
            "example": {},
            "type": {
              "type": "string"
            }
          },
          "required": [
            "type"
          ],
          "type": "object"
        }
      },
      "required": [
        "input"
      ],
      "type": "object"
    }
  },
  "discovery": {
    "discoverable": true,
    "info": {
      "input": {
        "bodyFields": {
          "expect_chain_id": {
            "description": "the chain id you BELIEVE you are talking to. When given, the response carries an explicit matches_native / matches_evm_facade verdict instead of leaving you to compare two numbers yourself — which is the comparison people get wrong.",
            "required": false,
            "type": "integer"
          },
          "expect_genesis_hash": {
            "description": "the genesis hash you have pinned (0x… 32 bytes). Compared byte-for-byte; a mismatch is reported as a hard failure, since it means this is not the chain you think it is.",
            "required": false,
            "type": "string"
          }
        },
        "bodyType": "json",
        "method": "POST",
        "queryParams": {
          "expect_chain_id": {
            "description": "same as body.expect_chain_id for GET callers",
            "type": "string"
          },
          "expect_genesis_hash": {
            "description": "same as body.expect_genesis_hash for GET callers",
            "type": "string"
          }
        },
        "type": "http"
      },
      "output": {
        "description": "as_of {read_at, head_height, head_hash}; native {chain_id, genesis_hash, genesis_header_hash, fork_id, policy_hash}; evm_facade {eth_chain_id, eth_chain_id_decimal, net_version, agrees_with_native, why_it_matters}; checkpoints {source, count, entries[] {height, hash}}; expectation {checked, chain_id {expected, matches_native, matches_evm_facade}, genesis_hash {expected, matches}}; warnings[]; read_errors; inference {used:false}.",
        "type": "json"
      }
    }
  }
}

curl "https://animica.dev/x402/chain/identity"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid

const res = await fetch("https://animica.dev/x402/chain/identity");
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://animica.dev/x402/chain/identity")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header