Self-Anchoring Overview | Ceramic documentation

On this page

Ceramic One supports self-anchoring, allowing you to run your own anchor service instead of relying on an external Ceramic Anchor Service (CAS). This gives you full control over your anchoring infrastructure and supports any EVM-compatible blockchain.

What is Anchoring?

Anchoring is the process of writing cryptographic commitments to a blockchain, providing a verifiable timestamp and ordering for Ceramic events. This ensures data integrity and enables conflict resolution across the decentralized network.

When events are anchored:

They receive a blockchain-verified timestamp
Their ordering becomes globally verifiable
Conflicts can be deterministically resolved

Benefits of Self-Anchoring

Independence: No reliance on external anchor services
Flexibility: Use any EVM-compatible blockchain
Control: Configure anchoring frequency and confirmation requirements
Cost Management: Choose networks with appropriate transaction costs for your use case

Prerequisites

Before configuring self-anchoring, ensure you have:

A running Ceramic One node - See Installation
Access to an EVM RPC endpoint - For submitting transactions and verifying anchor proofs
A funded wallet - The wallet must have sufficient funds for transaction fees on your chosen network
A deployed anchor contract - See Deploying the Anchor Contract

Quick Start

ceramic-one daemon \
  --evm-rpc-url https://rpc.yournetwork.com \
  --evm-private-key your-private-key-hex \
  --evm-chain-id 1 \
  --evm-contract-address 0x... \
  --anchor-interval 3600

Or use environment variables:

export CERAMIC_ONE_EVM_RPC_URL=https://rpc.yournetwork.com
export CERAMIC_ONE_EVM_PRIVATE_KEY=your-private-key-hex
export CERAMIC_ONE_EVM_CHAIN_ID=1
export CERAMIC_ONE_EVM_CONTRACT_ADDRESS=0x...
export CERAMIC_ONE_ANCHOR_INTERVAL=3600

ceramic-one daemon

See EVM Configuration for detailed setup instructions and all available options.

Configuration Summary

Option	Environment Variable	Purpose
`--evm-rpc-url`	`CERAMIC_ONE_EVM_RPC_URL`	Submit anchor transactions and verify proofs
`--evm-private-key`	`CERAMIC_ONE_EVM_PRIVATE_KEY`	Sign anchor transactions
`--evm-chain-id`	`CERAMIC_ONE_EVM_CHAIN_ID`	Target blockchain network
`--evm-contract-address`	`CERAMIC_ONE_EVM_CONTRACT_ADDRESS`	Anchor contract address
`--additional-chain-rpc-urls`	`CERAMIC_ONE_ADDITIONAL_CHAIN_RPC_URLS`	Validate anchors from other chains (optional)

How It Works

Event Collection: Ceramic One collects pending events that need anchoring
Merkle Tree Construction: Events are batched and organized into a Merkle tree
Blockchain Transaction: The Merkle root is written to the anchor contract on your chosen EVM chain
Confirmation: After the configured number of block confirmations, anchors are considered final
Proof Verification: The node verifies anchor proofs using the configured RPC endpoints
Proof Distribution: Anchor proofs are distributed to relevant streams

Next Steps

EVM Configuration - Detailed configuration options for EVM anchoring
Concepts - Learn more about Ceramic's event streaming architecture