> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blockdb.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Claude Skill

> A ready-to-use Claude skill (SKILL.md) that turns Claude into a BlockDB query agent for Ethereum and EVM on-chain data.

A [Claude skill](https://docs.claude.com/en/docs/agents-and-tools/agent-skills/overview) packages instructions Claude loads on demand. Drop the one below into your skills directory and Claude can answer on-chain questions by calling BlockDB.

## Create the skill

Save as `blockdb/SKILL.md`:

```markdown theme={null}
---
name: blockdb
description: Query Ethereum / EVM on-chain data (blocks, transactions, transfers, DEX swaps, pools, prices, TVL) via the BlockDB REST API. Use whenever the user asks for on-chain or DeFi data.
---

# BlockDB

Call the BlockDB REST API to answer on-chain data questions.

## Rules
- Base URL: `https://api.blockdb.io/v1`
- Auth: send `Authorization: Bearer <BLOCKDB_API_KEY>` on every request (key from env).
- All endpoints are `POST` + JSON body (filters in the body). Exception: `GET /usage`.
- Response: `{ "data": [...], "cursor": "<string|null>", "page_count": <number> }`.
  Paginate by resending the body with `cursor` until it is null.
- Always include `chain_id` (Ethereum = 1). Prefer `from_block`/`to_block`.
- Never invent chain_id, exchange_id, pool_type_id, or addresses. Resolve IDs from
  https://docs.blockdb.io/api-reference/enumerations/overview.

## Picking an endpoint
- Raw chain data → /api-reference/evm/primitives/overview
- Transfers → /api-reference/evm/transfers/token-transfers
- Swaps → /api-reference/evm/swaps/overview
- Prices → /api-reference/evm/prices/overview
- Full index → /api-reference/evm/overview

## Example
POST https://api.blockdb.io/v1/evm/transfers/token-transfers
{ "chain_id": 1, "from_block": 19000000, "to_block": 19001000, "limit": 250 }
```

## Example prompts

Once the skill is available, ask Claude directly:

> "What were the top 10 largest USDC transfers on Ethereum between blocks 19000000 and 19010000?"

> "Pull Uniswap v3 WETH/USDC swaps for yesterday and chart hourly volume."

## No-key path

For historical research, the [free datasets](/free-datasets/home) need no API key — tell Claude to read the Parquet files from Hugging Face.