# Base Sentinel Slippage Estimator

> Base Sentinel Slippage Estimator is a paid API for AI agents from demo.x402alpha.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Estimates safe slippage tolerance for token swaps on Base by analyzing pool depth and volatility metrics

## Facts

- Endpoint: GET https://demo.x402alpha.app/api/slippage-sentinel
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-sentinel-slippage-estimator-1810659f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dL2UiLbow6HgMG1-BrKl4

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 base-sentinel-slippage-estimator-1810659f
```

Example prompt: What's the safe slippage tolerance I should set when swapping 1000 USDC (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) for ETH (0x4200000000000000000000000000000000000006) on Base — give me the pool depth and volatility analysis too.

## When to prefer this

Use this endpoint when you need a quick, data-driven slippage recommendation before executing a token swap on the Base network, especially for large trades where pool depth and recent volatility materially affect execution risk. Prefer this over generic DEX frontends when you need programmatic slippage values with quantitative backing (volatility index, p95 trade size) for agent-driven trading or smart contract integrations.

## Known failure modes

- Invalid or non-checksummed token address returns error
- Token pair with no liquidity pool returns no data or zero pool depth
- Unsupported route hint returns fallback to default Base routing
- Amount input as non-numeric string causes parsing failure
- Network congestion may cause stale pool depth data

## How this service works

Safe slippage tolerance estimation for token swaps with pool depth and volatility analysis

## Output

Returns minimum safe slippage in basis points, total pool depth in USD, a volatility index from 0 to 100, the 95th percentile trade size in USD, and metadata about the token pair and route used — all as of the timestamp of the call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "token_in": {
   "type": "string (required): Input token address (0x-prefixed hex string)"
  },
  "amount_in": {
   "type": "string (required): Input amount as string (e.g., '1000')"
  },
  "token_out": {
   "type": "string (required): Output token address (0x-prefixed hex string)"
  },
  "route_hint": {
   "type": "string (optional): Route hint for DEX routing (default: 'base')"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "success": "boolean",
 "token_in": "string",
 "amount_in": "number",
 "timestamp": "string (ISO 8601)",
 "token_out": "string",
 "route_hint": "string (optional)",
 "pool_depths": "number: Total pool depth in USD",
 "volatility_index": "number: Volatility index (0-100)",
 "min_safe_slip_bps": "number: Minimum safe slippage in basis points",
 "recent_trade_size_p95": "number: 95th percentile trade size in USD"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-sentinel-slippage-estimator-1810659f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from demo.x402alpha.app](https://www.zero.xyz/host/demo.x402alpha.app/llms.txt)