# BlockRun.AI On-Chain ClickHouse Schema Introspection

> BlockRun.AI On-Chain ClickHouse Schema Introspection is a paid API for AI agents from blockrun.ai, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-13).

Returns the ClickHouse table schema for on-chain blockchain data, enabling structured query planning and data exploration.

## Facts

- Endpoint: GET https://blockrun.ai/api/v1/surf/onchain/schema
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/blockrun-ai-3e498368
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_kbshI0GkZWU1HDrpAYKWL

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 blockrun-ai-3e498368
```

Example prompt: Show me the ClickHouse table schema for BlockRun's on-chain data so I can understand what columns and data types are available to query.

## When to prefer this

Use this endpoint when you need to understand the structure of BlockRun's on-chain ClickHouse database before constructing queries — essential for query planning, data pipeline design, or exploring what blockchain data fields are available. Prefer over manual documentation lookups when building dynamic query generation or schema-aware data agents.

## Known failure modes

- Schema unavailable if underlying ClickHouse cluster is unreachable — returns 500 or timeout
- Authentication/payment failure via x402 protocol if USDC balance is insufficient — returns 402
- Rate limiting if too many schema requests are made in quick succession — returns 429

## How this service works

Pay for the outcome. One endpoint for every model, tool and data source an agent needs — each call priced before it runs, at the best value per dollar. 103 models and 100 data and tool APIs.

## Output

Returns a structured description of the ClickHouse table schema for on-chain blockchain data, including table names, column names, and data types that can be used to plan SQL queries against the database.

## Example request

```json
{
 "input": {
  "body": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/blockrun-ai-3e498368/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from blockrun.ai](https://www.zero.xyz/host/blockrun.ai/llms.txt)