# CoinCap Asset Market-Cap History

> CoinCap Asset Market-Cap History is a paid API for AI agents from rest.coincap.io, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns a historical time-series of market capitalization data points for a specific cryptocurrency asset identified by its CoinCap slug.

## Facts

- Endpoint: GET https://rest.coincap.io/v3/agentFriendly/asset_mcap_history/bitcoin
- 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/coincap-asset-market-cap-history-4da27224
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-6r6l2oP2BDCRlM-nRM7G

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 coincap-asset-market-cap-history-4da27224
```

Example prompt: Pull the historical market-cap series for bitcoin from CoinCap so I can see how its total valuation has changed over time.

## When to prefer this

Use this endpoint when you specifically need historical market capitalization data for a single cryptocurrency asset identified by its CoinCap slug. Prefer this over general price history endpoints when total market valuation (rather than per-unit price) is the metric of interest. It is ideal for trend analysis, charting market cap growth, or comparing an asset's historical valuation footprint.

## Known failure modes

- Invalid or unknown asset slug returns an error or empty result
- Rate limiting or payment failure results in a 402 or 429 response
- Network timeouts for slow responses
- Capped data points may not cover the full historical range requested
- Slug casing or formatting mismatch may cause lookup failure

## How this service works

Historical market-cap series for an asset slug (capped data points).

## Output

Returns a capped series of historical market capitalization data points for the specified asset slug, each containing a timestamp and the corresponding market cap value in USD, allowing analysis of how the asset's total market valuation has changed over time.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "pathParams": {
     "type": "object",
     "required": [
      "slug"
     ],
     "properties": {
      "slug": {
       "type": "string"
      }
     }
    },
    "queryParams": {
     "type": "object",
     "properties": {}
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/coincap-asset-market-cap-history-4da27224/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from rest.coincap.io](https://www.zero.xyz/host/rest.coincap.io/llms.txt)