# Tanod chainpeek – Uniswap V3 Pre-Trade Size & Impact Check

> Tanod chainpeek – Uniswap V3 Pre-Trade Size & Impact Check is a paid API for AI agents from tanod.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-18).

Quotes a Uniswap V3 swap at up to five trade sizes, returning price impact per size, the best fee tier and pool, and the gap to the latest DEX candle close on Ethereum or Base.

## Facts

- Endpoint: POST https://tanod.dev/v1/chain/pre-trade-check?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/tanod-chainpeek-uniswap-v3-pre-trade-size-impact-check-f454e5e0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_U8NiCHbQiWuS-ZrkKQhS3

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 tanod-chainpeek-uniswap-v3-pre-trade-size-impact-check-f454e5e0 -d '<json body>'
```

Example prompt: Before I swap, check the price impact on Uniswap V3 for trading WETH (0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2) to USDC (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) on Ethereum at three sizes — 1, 10, and 50 WETH — and tell me which fee tier and pool gives me the best deal.

## When to prefer this

Choose this endpoint when an agent needs to compare price impact across multiple swap sizes before committing to a Uniswap V3 trade on Ethereum or Base — especially for larger trades where slippage matters. It is purpose-built for pre-trade decision-making, combining multi-size quoting, fee-tier selection, and candle-gap analysis in a single call, avoiding the need to query Uniswap's SDK or subgraph directly.

## Known failure modes

- Invalid token address (not a valid 0x + 40 hex ERC-20 address) returns a validation error
- Unsupported chain value (not 'ethereum' or 'base') returns a 400 error
- No liquidity in any requested fee tier returns an error or null quotes for that size
- More than 5 sizes supplied returns a validation error
- Uniswap V3 subgraph or RPC unavailability returns a 503 or timeout
- Duplicate sizes in the array may return an error

## How this service works

chainpeek (Tanod) Uniswap V3 swap quoted at up to five sizes: price impact per size, best fee tier and pool, and the gap to the latest DEX candle close, on Ethereum or Base. Use when an agent is about to swap and needs the price impact at several sizes before choosing one.

## Output

Returns per-size quotes including the output amount, price impact, the recommended fee tier and pool address, and the spread versus the latest DEX candle close — ordered from smallest to largest trade size. Covers up to 5 sizes in a single call on Ethereum or Base.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "chain": {
   "enum": [
    "ethereum",
    "base"
   ],
   "type": "string",
   "description": "Chain to quote on (Uniswap V3): ethereum or base."
  },
  "sizes": {
   "type": "array",
   "items": {
    "type": "string",
    "pattern": "^(0|[1-9][0-9]{0,77})(\\.[0-9]{1,77})?$",
    "maxLength": 160
   },
   "maxItems": 5,
   "minItems": 1,
   "description": "1 to 5 amounts of token_in as positive decimal strings in token_in units, e.g. [\"1\", \"10\", \"100\"]. Distinct; answered smallest first."
  },
  "token_in": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "Token sold (0x + 40 hex)."
  },
  "fee_tiers": {
   "anyOf": [
    {
     "type": "array",
     "items": {
      "enum": [
       100,
       500,
       3000,
       10000
      ],
      "type": "integer"
     },
     "maxItems": 4,
     "minItems": 1
    },
    {
     "type": "null"
    }
   ],
   "default": null,
   "description": "Uniswap V3 fee tiers to consider (100, 500, 3000, 10000). Default: all four."
  },
  "token_out": {
   "type": "string",
   "pattern": "^0x[0-9a-fA-F]{40}$",
   "description": "Token bought (0x + 40 hex)."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/tanod-chainpeek-uniswap-v3-pre-trade-size-impact-check-f454e5e0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from tanod.dev](https://www.zero.xyz/host/tanod.dev/llms.txt)