# 3Route Multichain Swap Quote API

> 3Route Multichain Swap Quote API is a paid API for AI agents from 3route.agents.bakingbad.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns a swap quote (output token amount and gas estimate) for a given token pair and input amount on a specific EVM chain

## Facts

- Endpoint: GET https://3route.agents.bakingbad.dev/v1/pro/%7BchainId%7D/quote
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/3route-multichain-swap-quote-api-c8dc437c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5Ue5yqe_RGN_5L2aRWiC4

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability 3route-multichain-swap-quote-api-c8dc437c
```

Example prompt: Get me a swap quote on 3Route for chain 4663 — I want to sell 1 ETH (address 0x0000000000000000000000000000000000000000) and buy the token at 0x5fc5360d0400a0fd4f2af552add042d716f1d168, using an amount of 1000000000000000000 wei. How much will I receive and what's the estimated gas?

## When to prefer this

Use 3Route when you need an agent-native, pay-per-call swap quote API with multichain EVM support and x402 micropayment compatibility. Prefer it when building autonomous agents that need to price DeFi token swaps programmatically without a subscription, or when you need routing across multiple DEX protocols in a single API call. It is especially suited for on-chain agents that need to verify swap output before submitting a transaction.

## Known failure modes

- Missing required parameters (src, dst, amount) returns a 400 error
- Invalid token address format (not matching 0x hex pattern) returns a validation error
- Unsupported chainId (anything other than 4663) returns an error
- Amount of zero or non-integer string causes a validation failure
- No liquidity route found for the given token pair returns an error or empty route
- Payment not provided or insufficient USDC triggers a 402 Payment Required response

## How this service works

Best-priced crypto token swaps for agents, traders and apps. Pay-per-call quote & swap API via x402/MPP. No API key or subscription.

## Output

Returns a JSON object with the destination token amount (dstAmount), the source token amount (srcAmount), and an estimated gas cost for executing the swap. May optionally include protocol routing details, token info, and block number depending on query flags.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "chainId"
     ],
     "properties": {
      "chainId": {
       "enum": [
        "4663"
       ],
       "type": "string",
       "example": "4663",
       "pattern": "^[0-9]+$",
       "description": "Chain ID for the operation."
      }
     },
     "additionalProperties": false
    },
    "queryParams": {
     "type": "object",
     "required": [
      "src",
      "dst",
      "amount"
     ],
     "properties": {
      "dst": {
       "type": "string",
       "example": "0x5fc5360d0400a0fd4f2af552add042d716f1d168",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Address of the token being bought; take one from the token-list operation for the selected chain, or use the zero address, or the case-insensitive sentinel 0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee, for the chain's native asset."
      },
      "fee": {
       "type": "number",
       "default": 0,
       "maximum": 3,
       "minimum": 0
      },
      "src": {
       "type": "string",
       "example": "0x0000000000000000000000000000000000000000",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "Address of the token being sold; use the zero address, or the case-insensitive sentinel 0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee, for the chain's native asset"
      },
      "amount": {
       "type": "string",
       "example": "1000000000000000000",
       "pattern": "^[0-9]+$",
       "description": "Positive amount in smallest units, as an integer string."
      },
      "gasPrice": {
       "type": "string",
       "example": "1000000000",
       "pattern": "^[0-9]+$"
      },
      "protocols": {
       "type": "string"
      },
      "timestamp": {
       "type": "integer",
       "minimum": 0
      },
      "blockNumber": {
       "type": "integer",
       "minimum": 0
      },
      "isExactOutput": {
       "type": "boolean",
       "default": false
      },
      "includeProtocols": {
       "type": "boolean",
       "default": false
      },
      "excludedProtocols": {
       "type": "string"
      },
      "includeTok
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "gas": 210000,
  "dstAmount": "950000",
  "srcAmount": "1000000000000000000"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/3route-multichain-swap-quote-api-c8dc437c/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 3route.agents.bakingbad.dev](https://www.zero.xyz/host/3route.agents.bakingbad.dev/llms.txt)