Using eRPC with Chainstack: Quickstart

TLDR:

• Set up eRPC as a fault-tolerant proxy that automatically discovers and configures all your Chainstack nodes using the Platform API.
• Unlike other providers, Chainstack integration requires only a Platform API key to automatically fetch and configure all deployed nodes across multiple chains.
• Benefit from automatic node discovery, multi-chain support, smart filtering by project/region/provider, and dynamic configuration without manual endpoint management.
• Deploy using Docker with simple YAML configuration and test with standard JSON-RPC calls for production-ready blockchain infrastructure.

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Main article

eRPC is a fault-tolerant EVM RPC proxy with permanent caching and reorg awareness. One of its most powerful features is the built-in support for multiple blockchain infrastructure providers, including Chainstack.

This means:

• Automatic node discovery — eRPC fetches all your Chainstack nodes via API.
• Multi-chain support — Automatically supports all chains where you have nodes.
• Smart filtering — Filter nodes by project, organization, region, provider, and type.
• Dynamic configuration — No need to manually update configs when you deploy new nodes.

This tutorial will guide you through setting up eRPC as a fault-tolerant proxy for your Chainstack RPC endpoints, providing enhanced reliability, caching, and failover capabilities.

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Prerequisites

Before starting, ensure you have:

• A Chainstack account with deployed nodes.
• A Chainstack Platform API key.
• Docker installed.

And that’s about it.

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Step 1: Get your Chainstack Platform API key

The key difference with Chainstack is that you need a Platform API key, not a regular node endpoint API key.

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Creating a Platform API key

1. Log into your Chainstack console.
2. Navigate to Settings > API keys.
3. Click Create key.
4. Give it a descriptive name (e.g., “eRPC Integration”).
5. Copy the generated API key.

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Step 2: Deploy nodes

Deploy Global Nodes for EVM networks.

For this tutorial, let’s deploy nodes on a few different networks: Ethereum Mainnet, Polygon Mainnet, Arbitrum Mainnet.

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Step 3: Configure Chainstack integration

If you want a quick start, you can just stick with the basic configuration and explore other options later.

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Basic configuration

Create or edit your erpc.yaml file:

projects:
  - id: main
    networks:
      - architecture: evm
        evm:
          chainId: 1
      - architecture: evm
        evm:
          chainId: 137

    upstreams:
      # Chainstack auto-discovery — will find all nodes automatically
      - id: chainstack-auto
        endpoint: chainstack://YOUR_CHAINSTACK_PLATFORM_API_KEY
        rateLimitBudget: chainstack-developer
        failsafe:
          timeout:
            duration: 15s
          retry:
            maxAttempts: 2
            delay: 1000ms
            backoffMaxDelay: 10s
            backoffFactor: 0.3
            jitter: 500ms

rateLimiters:
  budgets:
    - id: chainstack-developer
      rules:
        - method: '*'
          maxCount: 25  # The lowest limit of the free Developer plan https://chainstack.com/pricing/
          period: 1s
        - method: 'eth_getLogs'
          maxCount: 10  # The lowest limit of the free Developer plan https://chainstack.com/pricing/
          period: 1s

Replace YOUR_CHAINSTACK_PLATFORM_API_KEY with your actual Platform API key.

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Advanced configuration with filtering

Chainstack’s integration supports powerful filtering options:

projects:
  - id: main
    networks:
      - architecture: evm
        evm:
          chainId: 1
      - architecture: evm
        evm:
          chainId: 137

    upstreams:
      # Chainstack auto-discovery — will find all nodes automatically
      - id: chainstack-auto
        endpoint: chainstack://YOUR_CHAINSTACK_PLATFORM_API_KEY?project=PROJECT-ID
        rateLimitBudget: chainstack-developer
        failsafe:
          timeout:
            duration: 15s
          retry:
            maxAttempts: 2
            delay: 1000ms
            backoffMaxDelay: 10s
            backoffFactor: 0.3
            jitter: 500ms

rateLimiters:
  budgets:
    - id: chainstack-developer
      rules:
        - method: '*'
          maxCount: 25  # The lowest limit of the free Developer plan https://chainstack.com/pricing/
          period: 1s
        - method: 'eth_getLogs'
          maxCount: 10  # The lowest limit of the free Developer plan https://chainstack.com/pricing/
          period: 1s

Replace YOUR_CHAINSTACK_PLATFORM_API_KEY with your actual Platform API key and PROJECT-ID with the ID of your project—for example, PR-123-456.

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Step 4: Run eRPC

Start eRPC using Docker:

docker run --rm -v $(pwd)/erpc.yaml:/erpc.yaml -p 4000:4000 -p 4001:4001 ghcr.io/erpc/erpc:main

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Step 5: Test your setup

Test the proxy with a simple request:

# Test Ethereum mainnet
curl --location 'http://localhost:4000/main/evm/1' \
--header 'Content-Type: application/json' \
--data '{
    "method": "eth_getBlockByNumber",
    "params": ["latest", false],
    "id": 1,
    "jsonrpc": "2.0"
}'

# Test Polygon mainnet
curl --location 'http://localhost:4000/main/evm/137' \
--header 'Content-Type: application/json' \
--data '{
    "method": "eth_blockNumber",
    "params": [],
    "id": 2,
    "jsonrpc": "2.0"
}'

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Advanced configuration

For more advanced configurations and features, refer to the eRPC documentation and the eRPC GitHub repository. Don’t forget to give them a star :star: for this awesome solution.

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About the author

Ake

Director of Developer Experience @ Chainstack

Talk to me all things Web3

20 years in technology | 8+ years in Web3 full time years experience

Trusted advisor helping developers navigate the complexities of blockchain infrastructure