# DripMetrics Kyle Lambda - Polymarket Price Impact Estimator

> DripMetrics Kyle Lambda - Polymarket Price Impact Estimator is a paid API for AI agents from api.dripmetrics.ai, paid per call via x402, $0.050000/call, status unknown (last checked 2026-09-15).

Estimates Kyle's Lambda (price impact per unit of signed notional flow) for a selected Polymarket YES or NO outcome over a specified time window

## Facts

- Endpoint: POST https://api.dripmetrics.ai/polymarket/kyle-lambda
- Price: $0.050000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-dripmetrics-ai-f817d29f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tOMhtF6kp6uAwwgqzolTs

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 api-dripmetrics-ai-f817d29f -d '<json body>'
```

Example prompt: What's the Kyle Lambda for the YES side of the Polymarket market with slug 'will-the-fed-cut-rates-in-july' over the last 60-minute window?

## When to prefer this

Use this endpoint when you need to quantify how much price moves per unit of net signed order flow on a specific Polymarket market — useful for assessing liquidity depth, informed trading risk, or execution cost before placing a large prediction market trade. Prefer this over generic volume or spread metrics when you need a rigorous microstructure-based impact coefficient.

## Known failure modes

- Invalid or unrecognized conditionId/tokenId/slug returns an error
- Missing required 'outcome' parameter causes request rejection
- Ambiguous event slug with multiple markets requires conditionId to disambiguate
- No trade data in the requested window returns null or zero lambda
- windowMinutes too narrow with insufficient trades reduces metric reliability
- Payment failure via x402 blocks the request

## How this service works

DripMetricsAI (https://dripmetrics.ai/) provides on-demand crypto market microstructure metrics, Hyperliquid candle metrics, Polymarket diagnostics, and on-chain DefiLlama metrics for agents, dashboards, and trading workflows.

## Output

A structured JSON object containing the Kyle Lambda value (price impact per unit of signed notional flow), the effective analysis window, metric name, and component breakdown for the selected Polymarket YES or NO outcome.

## Request schema (JSON Schema)

```json
{
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "type": "object",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "type": "string",
     "enum": [
      "POST"
     ]
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "conditionId": {
       "type": "string",
       "description": "Polymarket condition ID for trade-based metrics."
      },
      "slug": {
       "type": "string",
       "description": "Polymarket market or event slug for human-readable market selection. Multi-market event slugs may require conditionId to disambiguate."
      },
      "tokenId": {
       "type": "string",
       "description": "Polymarket token / asset ID for orderbook and price-history endpoints."
      },
      "assetId": {
       "type": "string",
       "description": "Alias for tokenId on price-history-based endpoints."
      },
      "outcome": {
       "type": "string",
       "enum": [
        "YES",
        "NO"
       ],
       "description": "Required for token-side Polymarket diagnostics when the selected YES or NO side must be interpreted."
      },
      "windowMinutes": {
       "type": "integer",
       "minimum": 1,
       "description": "Lookback window in minutes."
      },
      "limit": {
       "type": "integer",
       "minimum": 1,
       "maximum": 5000,
       "description": "Maximum number of trades to evaluate."
      },
      "startTs": {
       "type": "integer",
       "description": "Optional unix timestamp lower bound."
      },
      "endTs": {
       "type": "integer",
       "description": "Optional unix timestamp upper bound."
      },
      "lookbackMinutes": {
       "type": "integer",
       "minimum": 1,
       "description": "Historical lookback used for probability shock normalization."
      },
      "newsTs": {
       "type": "integer",
       "description": "Optional explicit event timestamp for leakage scoring. If omitted, the metric uses the midpoint of the effective analysis window."
      }
     },
     "required": [
      "outcome"
     ],
     "additionalProperties": false,
     "anyOf": [
      {
       "required": [
        "conditionId",
        "tokenId",
        "outcome"
       ]
      },
      {
       "required": [
        "conditionId",
        "assetId",
        "outcome"
       ]
      },
      {
       "required": [
        "slug",
        "outcome"
       ]
     
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "slug": "fed-decision-in-october",
  "value": 0.00169347,
  "metric": "kyle-lambda",
  "source": {
   "market": "https://gamma-api.polymarket.com/markets/slug/fed-decision-in-october",
   "trades": "https://data-api.polymarket.com/trades",
   "priceHistory": "https://clob.polymarket.com/prices-history"
  },
  "window": {
   "windowMinutes": 60
  },
  "assetId": "52114319501245791867035421127632480533667839244426816785285192633646117989903",
  "outcome": "YES",
  "tokenId": "52114319501245791867035421127632480533667839244426816785285192633646117989903",
  "components": {
   "alpha": -0.01128977,
   "lambda": 0.00169347,
   "rSquared": 0.997935,
   "intervals": 3,
   "lastPrice": 0.5,
   "meanSignedFlow": 6.666667,
   "selectedOutcome": "YES",
   "totalAbsoluteFlow": 29
  },
  "computedAt": "2026-05-25T14:00:00.000Z",
  "sampleSize": {
   "trades": 4,
   "pricePoints": 4,
   "scannedTrades": 4
  },
  "conditionId": "0xdd22472e552920b8438158ea7238bfadfa4f736aa4cee91a6b86c39ead110917"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-dripmetrics-ai-f817d29f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.dripmetrics.ai](https://www.zero.xyz/host/api.dripmetrics.ai/llms.txt)