Authentication & Response Formats

Base URL

https://api.paxoslabs.com

All endpoints are versioned under /v2.

Authentication

Include your API key in the x-api-key header on every request:

curl https://api.paxoslabs.com/v2/amplify/vaults \
  -H "x-api-key: pxl_your_public_id_your_secret"

API keys use the format pxl_<public_id>_<secret>. Obtain one from the Paxos Labs dashboard.

Response Format

The three transaction-preparation endpoints (deposit, withdraw, withdraw/cancel) accept a responseFormat query parameter that controls which fields appear in the response:

Format	`data` (hex calldata)	`abi` / `functionName` / `args`	Default
`encoded`	Yes	No	Yes
`full`	Yes	Yes
`structured`	No	Yes

`encoded` (default)

Returns only the ABI-encoded calldata hex string. Use this when your signer accepts raw data fields (e.g. eth_sendTransaction).

curl "https://api.paxoslabs.com/v2/amplify/deposit?\
vaultAddress=0xbbbb000000000000000000000000000000000001&\
depositAsset=0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48&\
depositAmount=1000000&\
userAddress=0x1234567890abcdef1234567890abcdef12345678&\
chainId=1" \
  -H "x-api-key: pxl_your_key"

{
  "transaction": {
    "to": "0xcccc000000000000000000000000000000000001",
    "data": "0x47e7ef24000000000000000000000000...",
    "value": "0"
  }
}

`full`

Returns encoded calldata plus the ABI fragment, function name, and decoded args. Useful for debugging or when you need both representations.

curl "https://api.paxoslabs.com/v2/amplify/deposit?\
vaultAddress=0xbbbb...&depositAsset=0xA0b8...&depositAmount=1000000&\
userAddress=0x1234...&chainId=1&responseFormat=full" \
  -H "x-api-key: pxl_your_key"

{
  "transaction": {
    "to": "0xcccc000000000000000000000000000000000001",
    "data": "0x47e7ef24000000000000000000000000...",
    "value": "0",
    "abi": [{ "type": "function", "name": "deposit", "inputs": [...], "outputs": [...] }],
    "functionName": "deposit",
    "args": ["0xA0b8...", "1000000", "999500", "0x1234..."]
  }
}

`structured`

Returns the ABI fragment, function name, and args without encoded calldata. Use this when your library handles encoding (e.g. viem encodeFunctionData, ethers interface.encodeFunctionData).

{
  "transaction": {
    "to": "0xcccc000000000000000000000000000000000001",
    "value": "0",
    "abi": [{ "type": "function", "name": "deposit", "inputs": [...], "outputs": [...] }],
    "functionName": "deposit",
    "args": ["0xA0b8...", "1000000", "999500", "0x1234..."]
  }
}

Error Handling

All error responses use a standard envelope:

{
  "error": {
    "code": 400,
    "message": "vaultAddress is not a valid hex address",
    "status": "INVALID_ARGUMENT",
    "details": [
      {
        "@type": "type.paxoslabs.dev/errors/BadRequest",
        "fieldViolations": [
          { "field": "vaultAddress", "description": "vaultAddress 0xinvalid is not a valid hex address." }
        ]
      }
    ]
  }
}

HTTP Status	`error.status`	Meaning
400	`INVALID_ARGUMENT`	Malformed or missing parameters
401	`UNAUTHENTICATED`	Missing or malformed API key
403	`PERMISSION_DENIED`	Invalid, inactive, or expired API key
404	`NOT_FOUND`	Vault not found for the given address + chain
429	`RESOURCE_EXHAUSTED`	Rate limit exceeded
503	`INTERNAL`	RPC or upstream service unavailable

Getting started

Amplify

USDG0

Authentication & Response Formats

Base URL

Authentication

Response Format

`encoded` (default)

`full`

`structured`

Error Handling

​Base URL

​Authentication

​Response Format

​encoded (default)

​full

​structured

​Error Handling

Base URL

Authentication

Response Format

`encoded` (default)

`full`

`structured`

Error Handling