Skip to main content

What is RPC

What is RPC

RPC (Remote Procedure Call) is a communication protocol that allows an application to request a service from a program running on another computer without needing to understand the details of that computer's network. In the blockchain context, RPC is how wallets, decentralized applications, block explorers, and other software communicate with blockchain nodes — sending transactions, querying balances, reading smart contract state, and retrieving block data.

In short: RPC is the standard interface through which applications talk to blockchain nodes — it is the communication layer that connects dApps, wallets, and tools to the blockchain network itself.

How RPC works in blockchain

Every blockchain node exposes an RPC endpoint — a URL that accepts structured requests and returns structured responses. When an application needs to interact with the blockchain, it sends an RPC request to this endpoint.

Request-response pattern

The interaction follows a standard client-server pattern:

  1. Request. The application (client) sends a request to the node's RPC endpoint. The request specifies which method to call and provides any necessary parameters. For example: "get the balance of address 0x742d...bD38" or "send this signed transaction to the network."
  2. Processing. The node receives the request, performs the requested operation — reading from its local copy of the blockchain or broadcasting a transaction to the network — and prepares a response.
  3. Response. The node returns the result to the application in a structured format (typically JSON).

JSON-RPC

Most blockchain networks use JSON-RPC — a lightweight protocol where requests and responses are formatted as JSON objects. A typical JSON-RPC request includes a method name (like eth_getBalance, eth_sendRawTransaction, or eth_call) and an array of parameters. The response contains the result or an error message.

This standardized format means that any application that understands JSON-RPC can interact with any node that implements the same methods, regardless of the programming language or framework used on either side.

Common RPC operations

Blockchain RPC endpoints typically support operations such as:

  • Reading state — querying account balances, token holdings, smart contract storage, and current block number.
  • Sending transactions — broadcasting signed transactions to the network for inclusion in a block.
  • Calling smart contracts — executing read-only smart contract functions without creating a transaction (no gas cost).
  • Subscribing to events — listening for specific on-chain events like token transfers, contract deployments, or new blocks.
  • Retrieving history — fetching past transactions, logs, and block data.

RPC providers

Running a full blockchain node requires significant storage, bandwidth, and maintenance. Many developers and applications use RPC providers — third-party services that operate node infrastructure and expose RPC endpoints for public or paid use. These providers offer reliable, high-availability access to blockchain data without requiring each application to run its own node.

Why it matters for crypto AI projects

RPC is the communication layer that every blockchain-based AI project depends on, even if it is not always visible to end users.

Interacting with smart contracts. AI projects that deploy smart contracts need RPC to read contract state, trigger functions, and submit transactions. Whether a project is distributing compute tasks, recording inference results, or managing staking, every on-chain interaction passes through an RPC endpoint.

Data ingestion. AI systems that analyze on-chain activity — trading patterns, wallet behaviors, protocol metrics — rely on RPC calls to ingest blockchain data. The speed and reliability of RPC access directly affects the quality and timeliness of AI analytics.

Infrastructure dependency. For AI projects that operate decentralized node networks, the RPC layer is how external users access the service. A decentralized compute marketplace exposes RPC endpoints for task submission; an AI inference network uses RPC for result delivery. The reliability of these endpoints determines the user experience.

Where this appears in DecAIHub project cards

RPC is not listed as a standalone field in project cards, but it underpins several aspects of a project's architecture:

  • Main chain — every main chain has its own RPC specification. The choice of chain determines which RPC methods are available and how applications interact with the network.
  • Type — projects that provide RPC infrastructure as a service (node providers, API gateways) may be classified based on their infrastructure role.
  • dApp and smart contract interaction — any project with on-chain smart contracts relies on RPC for all external interactions with those contracts.

What RPC alone does not prove

  • Decentralization — using a centralized RPC provider means the application depends on a single point of failure. If the provider goes down or censors requests, the application loses access to the blockchain. Running through a centralized RPC gateway does not make an application decentralized.
  • Security — RPC endpoints can be public or private, rate-limited or open. A public RPC endpoint does not inherently provide security guarantees. Applications that send sensitive transactions should ensure they are using trusted, authenticated endpoints.
  • On-chain execution — sending an RPC request does not mean the operation happens on-chain. Read-only calls (eth_call) execute locally on the node without creating a transaction. Only signed transactions submitted through RPC actually modify the blockchain state.
  • Performance — RPC response times depend on the node's hardware, network conditions, and provider infrastructure. A slow RPC connection does not indicate a slow blockchain; it may indicate an overloaded or geographically distant node.

Do not confuse with

  • API — RPC is a type of API, but not all APIs are RPC. REST APIs, GraphQL endpoints, and WebSocket interfaces are alternative communication patterns. In blockchain, "RPC" specifically refers to the JSON-RPC interface exposed by nodes.
  • Node — a node is the actual computer running blockchain software. RPC is the interface through which external applications communicate with that node. The node does the work; RPC is the door.
  • SDK / Library — libraries like Web3.js, Ethers.js, or Web3.py simplify RPC interactions by wrapping raw JSON-RPC calls in developer-friendly functions. The library is a convenience layer; RPC is the underlying protocol.
  • Oracle — an oracle brings off-chain data to the blockchain. RPC is how applications read and write on-chain data. They serve different roles: oracles bridge external data in, while RPC provides access to data that is already on-chain.

Frequently asked questions

Do I need to run my own node to use RPC?

No. Most developers and applications use third-party RPC providers that operate node infrastructure as a service. These providers offer RPC endpoints accessible via standard HTTP or WebSocket connections. Running your own node gives you full control and eliminates dependency on a third party, but it requires significant resources. For most use cases, a reputable RPC provider is sufficient.

What happens if an RPC provider goes down?

If the RPC provider your application uses goes down, the application loses its connection to the blockchain. It cannot read state, submit transactions, or receive event notifications until the connection is restored or the application switches to an alternative endpoint. For this reason, production applications often configure multiple fallback RPC endpoints from different providers.

Is RPC the same as blockchain access?

RPC is the most common method of blockchain access, but it is not the only one. Some applications use alternative protocols like GraphQL-based indexers or direct peer-to-peer connections. However, JSON-RPC remains the standard interface for general-purpose blockchain interaction, and virtually every wallet, dApp, and blockchain tool uses it behind the scenes.

External references

See also

No comments to display

Back to top