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

# Indexing Co

[Indexing Co](https://indexing.co) provides custom blockchain data pipelines with JavaScript transformation logic, sub-second latency, and delivery to Postgres, webhooks, or Kafka. Indexing Co supports Celo and 100+ other blockchains, making it easy to build cross-chain data workflows from a single platform.

## How It Works

Indexing Co pipelines have three stages:

| Stage              | Description                                                                                              |
| ------------------ | -------------------------------------------------------------------------------------------------------- |
| **Filter**         | Select which blocks and transactions to process by contract address, event signature, or other criteria. |
| **Transformation** | Write JavaScript functions that extract and reshape the data you need from each block.                   |
| **Destination**    | Deliver processed data to Postgres, HTTP webhooks, WebSockets, or other adapters.                        |

## Key Features

* **Celo support** — Native support for Celo mainnet with real-time and historical data.
* **Custom JavaScript transformations** — Write `function main(block)` handlers with full control over how data is extracted and shaped.
* **Multiple destinations** — Deliver data to Postgres, HTTP endpoints, WebSockets, or Kafka.
* **Backfills** — Replay historical blocks through your pipeline to populate your database from any starting point.
* **Cross-chain** — Run the same pipeline logic across 100+ supported blockchains.
* **Built-in helpers** — Use `templates.tokenTransfers(block)`, `utils.evmDecodeLog()`, and other utilities to accelerate development.

## Quick Start

All API requests use the base URL `https://app.indexing.co/dw` and require an `X-API-KEY` header for authentication. Sign up at [indexing.co](https://indexing.co) to get your API key.

### Step 1: Create a Filter

Create a filter to select which Celo transactions to process. This example filters for a specific contract address:

```bash theme={null}
curl -X POST https://app.indexing.co/dw/filters/my-celo-filter \
  -H "Content-Type: application/json" \
  -H "X-API-KEY: YOUR_API_KEY" \
  -d '{
    "addresses": ["0xYOUR_CONTRACT_ADDRESS"]
  }'
```

### Step 2: Create a Transformation

Create a transformation with a JavaScript `function main(block)` handler that processes each block:

```bash theme={null}
curl -X POST https://app.indexing.co/dw/transformations/my-celo-transform \
  -H "Content-Type: application/json" \
  -H "X-API-KEY: YOUR_API_KEY" \
  -d '{
    "code": "function main(block) {\n  const transfers = templates.tokenTransfers(block);\n  return transfers.map(t => ({\n    from: t.from,\n    to: t.to,\n    value: t.value,\n    token: t.address,\n    block_number: block.number,\n    timestamp: block.timestamp\n  }));\n}"
  }'
```

### Step 3: Test the Transformation

Test your transformation against a real Celo block to verify the output:

```bash theme={null}
curl -X POST "https://app.indexing.co/dw/transformations/test?network=celo&beat=BLOCK_NUMBER" \
  -H "Content-Type: application/json" \
  -H "X-API-KEY: YOUR_API_KEY" \
  -d '{
    "code": "function main(block) {\n  const transfers = templates.tokenTransfers(block);\n  return transfers.map(t => ({\n    from: t.from,\n    to: t.to,\n    value: t.value,\n    token: t.address,\n    block_number: block.number,\n    timestamp: block.timestamp\n  }));\n}"
  }'
```

### Step 4: Create a Pipeline

Combine the filter, transformation, and a destination into a pipeline that delivers data to Postgres:

```bash theme={null}
curl -X POST https://app.indexing.co/dw/pipelines \
  -H "Content-Type: application/json" \
  -H "X-API-KEY: YOUR_API_KEY" \
  -d '{
    "name": "my-celo-pipeline",
    "network": "celo",
    "filter": "my-celo-filter",
    "transformation": "my-celo-transform",
    "adapter": {
      "type": "POSTGRES",
      "config": {
        "connection_url": "postgresql://user:password@host:5432/dbname",
        "table": "celo_transfers"
      }
    }
  }'
```

## Backfilling Historical Data

Once your pipeline is running, you can backfill historical data from any starting block:

```bash theme={null}
curl -X POST https://app.indexing.co/dw/pipelines/my-celo-pipeline/backfill \
  -H "Content-Type: application/json" \
  -H "X-API-KEY: YOUR_API_KEY" \
  -d '{
    "start_block": 20000000
  }'
```

## Claude Code Integration

Indexing Co provides first-class support for [Claude Code](https://docs.anthropic.com/en/docs/claude-code) through an MCP server and a pipeline skill, enabling you to build and query Celo data pipelines directly from your AI coding workflow.

### MCP Server

The [Indexing Co MCP server](https://github.com/indexing-co/indexing-co-mcp) streams real-time blockchain data from your pipelines into Claude Code. Events are stored in local SQLite and queryable with SQL — no external database needed for development.

```bash theme={null}
# Install
git clone https://github.com/indexing-co/indexing-co-mcp.git
cd indexing-co-mcp && npm install && npm run build

# Register with Claude Code
claude mcp add indexing-co -- node /path/to/indexing-co-mcp/dist/index.js
```

Once registered, Claude Code gains tools to subscribe to pipeline channels, query event data with SQL, and manage pipelines, filters, and transformations — all through natural conversation.

To stream Celo data into Claude Code, set the pipeline destination to the `DIRECT` adapter:

```json theme={null}
{
  "adapter": "DIRECT",
  "connectionUri": "my-celo-channel",
  "table": "my-celo-channel"
}
```

### Claude Code Skill

The [Indexing Co pipeline skill](https://github.com/indexing-co/indexing-co-pipeline-skill) guides Claude through building and deploying pipelines via conversation. Install it to let Claude help you write transformation functions, generate SQL schemas, and manage pipelines:

```bash theme={null}
git clone https://github.com/indexing-co/indexing-co-pipeline-skill.git
cp -r indexing-co-pipeline-skill/skills/indexing-co-pipelines ~/.claude/skills/
```

## Resources

* [Documentation](https://docs.indexing.co)
* [Platform](https://indexing.co)
* [GitHub](https://github.com/indexing-co)
* [MCP Server](https://github.com/indexing-co/indexing-co-mcp)
* [Claude Code Skill](https://github.com/indexing-co/indexing-co-pipeline-skill)
* [Support](mailto:support@indexing.co)