# P0 Agent Economy Index – /concentration

> P0 Agent Economy Index – /concentration is a paid API for AI agents from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-13).

Returns market concentration metrics (HHI, top-seller shares, payer bounds) for x402 services grouped by tag, sourced from live 30-day payment data

## Facts

- Endpoint: GET https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/concentration?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/p0-agent-economy-index-concentration-76788374
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_yDVN6BiXt9UtCIIGSMgVe

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 p0-agent-economy-index-concentration-76788374
```

Example prompt: Can you pull the P0 Agent Economy concentration data for the 'ai' tag and tell me how monopolized that corner of the x402 market is — what's the HHI, the top seller share, and which service leads by paying wallets?

## When to prefer this

Use this endpoint when you need market structure analytics for the x402 service economy — specifically concentration metrics like HHI and seller share — rather than just a ranked list of services. Prefer it over the ranked-listing endpoints when the user wants to understand competitive dynamics, monopoly risk, or category diversity rather than finding the best individual service to call.

## Known failure modes

- Stale snapshot: stale:true returned if the underlying index hasn't refreshed within expected window, snapshot_age_s will be large
- Unknown tag: returns empty categories array if the provided tag has no indexed services
- Invalid tag format: malformed or unsupported tag strings may return empty results or a 400-level error
- Service unavailable: Cloudflare Worker cold start or upstream Bazaar catalog unavailability may cause timeout or 5xx

## How this service works

An open index of the machine-to-machine (agent) economy. x402 routes: ranked discovery over the live x402 service market, every indexed service scored by real 30-day calls and paying-wallet bounds, with a receipt naming the snapshot hash and scoring revision. /economy routes, for Tempo MPP, Virtuals ACP, Olas, Masumi, ERC-8004 agent registries, Solana agent registries, Base agent contracts and MCP servers (Official MCP Registry): each protocol's published figures (agent or server counts, transactions or payment events; payers and USD volume only where the source publishes them: payers for x402 and Tempo MPP, USD volume for x402 and Virtuals ACP), each with its unit, window and source; units differ, so totals are not summed. L402 and per-service MPP listings are not covered.

## Output

A JSON object with per-tag concentration metrics including HHI, top-1 and top-3 payer share, top-1 seller share, total services and sellers, zero-payer service count, an upper-bound sum of unique payers, and a ranked list of top resources with their 30-day payer counts. Includes snapshot timestamp, staleness flag, data source attribution, and a note clarifying that payer sums are upper bounds.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "tag": {
       "type": "string",
       "description": "optional: one tag (lowercase; a space as %20 or +), e.g. ai or market data; omitted = top tags by summed payers"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "v",
      "as_of",
      "generated_at",
      "labels",
      "tag",
      "categories",
      "categories_total",
      "stale",
      "snapshot_age_s",
      "source",
      "source_url",
      "note"
     ],
     "properties": {
      "v": {
       "type": "number"
      },
      "tag": {},
      "note": {
       "type": "string"
      },
      "as_of": {
       "type": "string"
      },
      "stale": {
       "type": "boolean"
      },
      "labels": {
       "type": "object",
       "properties": {
        "calls_30d": {
         "type": "string"
        },
        "invocations": {},
        "paid_outcome": {
         "type": "string"
        }
       }
      },
      "source": {
       "type": "string"
      },
      "categories": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "hhi": {
          "type": "number"
         },
         "tag": {
          "type": "string"
         },
         "top": {
          "type": "array",
          "items": {
           "type": "object",
           "properties": {
            "resource": {
             "type": "string"
            },
            "payers30d": {
             "type": "number"
            }
           }
          }
         },
         "sellers": {
          "type": "number"
         },
         "services": {
          "type": "number"
         },
         "top1_share": {
          "type": "number"
         },
         "top3_share": {
          "type": "number"
         },
         "top1_seller_share": {
          "type": "number"
         },
        
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "v": 1,
  "tag": null,
  "note": "payers_sum is an upper bound of unique payers in a tag. Format sample: totals, coverage, cohorts and per-chain rows are our real computation of 2026-10-05; per-tag, per-service and per-pair list entries are illustrative placeholders.",
  "as_of": "2026-10-04T18:24:44+00:00",
  "stale": false,
  "labels": {
   "calls_30d": "calls_30d are paid outcomes: settlements recorded by the CDP facilitator. Unpaid invocations (402 challenges, probes, failed verifies) are not observable in public data, so invocations is null.",
   "invocations": null,
   "paid_outcome": "a facilitator-recorded settlement (catalog calls_30d) or an on-chain transfer to a listed payTo address (scans, not verified as x402 settlements)"
  },
  "source": "P0 demand metrics: Coinbase CDP x402 Bazaar catalog (public) + P0 on-chain scans of USDC transfers to listed x402 payTo addresses",
  "categories": [
   {
    "hhi": 0.2311,
    "tag": "example-tag",
    "top": [
     {
      "resource": "https://api.example-seller.dev/v1/search",
      "payers30d": 130
     }
    ],
    "sellers": 4,
    "services": 12,
    "top1_share": 0.4194,
    "top3_share": 0.7742,
    "top1_seller_share": 0.5161,
    "zero_payer_services": 3,
    "payers_sum_upper_bound": 310
   }
  ],
  "source_url": "https://api.cdp.coinbase.com/platform/v2/x402/discovery/resources",
  "generated_at": "2026-10-05T00:30:00Z",
  "snapshot_age_s": 600,
  "categories_total": 5001
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/p0-agent-economy-index-concentration-76788374/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev](https://www.zero.xyz/host/x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/llms.txt)