Help Needed with Jupiter API Swap Execution - "Failed to Deserialize JSON" Error

[scatterblast]

Hello,

I’ve been working on integrating Jupiter’s API to build a trading bot and have successfully implemented the following:

1. Quote API:

Successfully retrieved valid quotes from the /v6/quote endpoint using Postman and my application code.

Example response from /v6/quote:

{
"inputMint": "So11111111111111111111111111111111111111112",
"inAmount": "100000000",
"outputMint": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"outAmount": "19299219",
"routePlan": [
{
"swapInfo": {
"ammKey": "5zvhFRN45j9oePohUQ739Z4UaSrgPoJ8NLaS2izFuX1j",
"inputMint": "So11111111111111111111111111111111111111112",
"outputMint": "Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB",
"inAmount": "100000000",
"outAmount": "19268051",
"feeAmount": "10000",
"feeMint": "So11111111111111111111111111111111111111112"
},
"percent": 100
}
]
}

2. Swap API:

I am attempting to execute a swap using the /v6/swap endpoint with the routePlan provided by the quote API.

---

Problem Statement

Despite following the documentation, I am encountering the following error when attempting to call /v6/swap:

{
"error": "Failed to deserialize the JSON body into the target type"
}

---

Current Setup

Here’s the payload I’m sending to /v6/swap:

{
"inputMint": "So11111111111111111111111111111111111111112",
"outputMint": "EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",
"amount": "100000000",
"slippageBps": 50,
"userPublicKey": "CzecDkTumsPDkRfksDeXGvinCd3P4aTFUSt7UpktFjoL",
"routePlan": [
{
"ammKey": "5zvhFRN45j9oePohUQ739Z4UaSrgPoJ8NLaS2izFuX1j",
"inputMint": "So11111111111111111111111111111111111111112",
"outputMint": "Es9vMFrzaCERmJfrF4H2FYD4KCoNkY11McCe8BenwNYB",
"inAmount": "100000000",
"outAmount": "19268051",
"feeAmount": "10000",
"feeMint": "So11111111111111111111111111111111111111112"
}
]
}

Key Details:

Headers Used:

{
"Content-Type": "application/json",
"Accept": "application/json"
}

Environment: Mainnet

Libraries Used: Postman for testing and Node.js (with axios for HTTP requests).

---

Steps Taken to Debug:

1. Validated Payload:

Verified the JSON payload using JSONLint to ensure it is properly formatted.

Cross-checked the payload against the /v6/swap documentation.

2. Confirmed Route Details:

The routePlan field was directly extracted from the /v6/quote response.

Confirmed that inputMint, outputMint, and ammKey are valid Solana addresses.

3. Tested in Postman:

The same error occurs when testing with Postman, confirming the issue is not specific to my application.

4. Tried Simplified Payloads:

Removed routePlan and sent only required fields to see if the error changes. The same error persists.

---

Request for Assistance

Could you please help me identify:

1. If there are any known issues or specific formatting requirements for the routePlan or the entire payload that I might have missed?

2. If additional headers, authentication tokens, or other parameters are required?

3. Any specific debugging tools or techniques recommended for this endpoints?

Thank you in advance!