RPC daemon

Remote Procedure Call

The RPC daemon is a crucial component of Erigon, enabling JSON remote procedure calls and providing access to various APIs.

Erigon RPC Method Guidelines

This document provides guidelines for understanding and using the various RPC methods available in Erigon.

1. Compatibility with eth namespace

   • Erigon aims to be compatible with all standard Ethereum JSON-RPC API methods, as described here. See also here for examples.

2. Compatibility with standard Geth methods

   • All methods featured by Geth including WebSocket Server, IPC Server, TLS, GraphQL, etc..., are supported by Erigon.

3. Otterscan Methods (ots_)

   • In addition to the standard Geth methods, Erigon includes RPC methods prefixed with ots_ for Otterscan. These are specific to the Otterscan functionality integrated with Erigon. See more details here.

4. Erigon Extensions (erigon_)

   • Erigon introduces some small extensions to the Geth API, denoted by the erigon_ prefix aimed to enhance the functionality, see more details here about implementation status.

5. gRPC API

   • Erigon also exposes a gRPC API for lower-level data access. This is primarily used by Erigon’s components when they are deployed separately as independent processes (either on the same or different servers).

   • This gRPC API is also accessible to users. For more information, visit the Erigon Interfaces GitHub repository.

6. Trace Module (trace_)

   • Erigon includes the trace_ module, which originates from OpenEthereum. This module provides additional functionality related to tracing transactions and state changes, which is valuable for advanced debugging and analysis.

More information

For a comprehensive understanding of the RPC daemon's functionality, configuration, and usage, please refer to https://github.com/erigontech/erigon/blob/main/cmd/rpcdaemon/README.md* (also contained in your locally compiled Erigon folder at /cmd/rpcdaemon) which covers the following key topics:

1. Introduction: An overview of the RPC daemon, its benefits, and how it integrates with Erigon.

2. Getting Started: Step-by-step guides for running the RPC daemon locally and remotely, including configuration options and command-line flags.

3. Healthcheck: Information on performing health checks using POST requests or GET requests with custom headers.

4. Testing and debugging: Examples of testing the RPC daemon using curl commands and Postman, debugging.

5. FAQ: Frequently asked questions and answers covering topics such as prune options, RPC implementation status, and securing communication between the RPC daemon and Erigon instance.

6. For Developers: Resources for developers, including code generation and information on working with the RPC daemon.

7. Relations between prune options and RPC methods: Explains how prune options affect RPC methods.

8. RPC Implementation Status: Provides a table showing the current implementation status of Erigon's RPC daemon.

9. Securing the communication between RPC daemon and Erigon instance via TLS and authentication: Outlines the steps to secure communication between the RPC daemon and Erigon instance.

10. Ethstats: Describes how to run ethstats with the RPC daemon.

11. Allowing only specific methods (Allowlist): Explains how to restrict access to specific RPC methods.

Command Line Options

rpcdaemon is JSON RPC server that connects to Erigon node for remote DB access

Usage:
  rpcdaemon [flags]

Flags:
      --datadir string                 path to Erigon working directory
      --db.read.concurrency int        Does limit amount of parallel db reads. Default: equal to GOMAXPROCS (or number of CPU) (default 192)
      --graphql                        enables graphql endpoint (disabled by default)
      --grpc                           Enable GRPC server
      --grpc.addr string               GRPC server listening interface (default "localhost")
      --grpc.healthcheck               Enable GRPC health check
      --grpc.port int                  GRPC server listening port (default 8547)
  -h, --help                           help for rpcdaemon
      --http.addr string               HTTP-RPC server listening interface (default "localhost")
      --http.api strings               API's offered over the HTTP-RPC interface: eth,erigon,web3,net,debug,trace,txpool,db. Supported methods: https://github.com/erigontech/erigon/tree/devel/cmd/rpcdaemon (default [eth,erigon])
      --http.compression               Disable http compression (default true)
      --http.corsdomain strings        Comma separated list of domains from which to accept cross origin requests (browser enforced)
      --http.port int                  HTTP-RPC server listening port (default 8545)
      --http.timeouts.idle duration    Maximum amount of time to wait for the next request when keep-alives are enabled. If http.timeouts.idle is zero, the value of http.timeouts.read is used (default 2m0s)
      --http.timeouts.read duration    Maximum duration for reading the entire request, including the body. (default 30s)
      --http.timeouts.write duration   Maximum duration before timing out writes of the response. It is reset whenever a new request's header is read (default 30m0s)
      --http.trace                     Trace HTTP requests with INFO level
      --http.vhosts strings            Comma separated list of virtual hostnames from which to accept requests (server enforced). Accepts '*' wildcard. (default [localhost])
      --log.console.json               Format console logs with JSON
      --log.console.verbosity string   Set the log level for console logs (default "info")
      --log.dir.json                   Format file logs with JSON
      --log.dir.path string            Path to store user and error logs to disk
      --log.dir.prefix string          The file name prefix for logs stored to disk
      --log.dir.verbosity string       Set the log verbosity for logs stored to disk (default "info")
      --log.json                       Format console logs with JSON
      --metrics                        Enable metrics collection and reporting
      --metrics.addr string            Enable stand-alone metrics HTTP server listening interface (default "127.0.0.1")
      --metrics.port int               Metrics HTTP server listening port (default 6060)
      --pprof                          Enable the pprof HTTP server
      --pprof.addr string              pprof HTTP server listening interface (default "127.0.0.1")
      --pprof.cpuprofile string        Write CPU profile to the given file
      --pprof.port int                 pprof HTTP server listening port (default 6060)
      --private.api.addr string        Erigon's components (txpool, rpcdaemon, sentry, downloader, ...) can be deployed as independent Processes on same/another server. Then components will connect to erigon by this internal grpc API. Example: 127.0.0.1:9090 (default "127.0.0.1:9090")
      --rpc.accessList string          Specify granular (method-by-method) API allowlist
      --rpc.batch.concurrency uint     Does limit amount of goroutines to process 1 batch request. Means 1 bach request can't overload server. 1 batch still can have unlimited amount of request (default 2)
      --rpc.batch.limit int            Maximum number of requests in a batch (default 100)
      --rpc.evmtimeout duration        Maximum amount of time to wait for the answer from EVM call. (default 5m0s)
      --rpc.gascap uint                Sets a cap on gas that can be used in eth_call/estimateGas (default 50000000)
      --rpc.returndata.limit int       Maximum number of bytes returned from eth_call or similar invocations (default 100000)
      --rpc.streaming.disable          Erigon has enalbed json streaming for some heavy endpoints (like trace_*). It's treadoff: greatly reduce amount of RAM (in some cases from 30GB to 30mb), but it produce invalid json format if error happened in the middle of streaming (because json is not streaming-friendly format)
      --rpc.txfeecap float             Sets a cap on transaction fee (in ether) that can be sent via the RPC APIs (0 = no cap) (default 1)
      --snapshot                       Default: use snapshots "true" for Mainnet, Goerli, Gnosis Chain and Chiado. use snapshots "false" in all other cases (default true)
      --state.cache string             Amount of data to store in StateCache (enabled if no --datadir set). Set 0 to disable StateCache. Defaults to 0MB RAM (default "0MB")
      --tcp                            Enable TCP server
      --tcp.addr string                TCP server listening interface (default "localhost")
      --tcp.port int                   TCP server listening port (default 8548)
      --tls.cacert string              CA certificate for client side TLS handshake
      --tls.cert string                certificate for client side TLS handshake
      --tls.key string                 key file for client side TLS handshake
      --trace string                   Write execution trace to the given file
      --trace.compat                   Bug for bug compatibility with OE for trace_ routines
      --trace.maxtraces uint           Sets a limit on traces that can be returned in trace_filter (default 200)
      --txpool.api.addr string         txpool api network address, for example: 127.0.0.1:9090 (default: use value of --private.api.addr)
      --verbosity string               Set the log level for console logs (default "info")
      --ws                             Enable Websockets - Same port as HTTP
      --ws.compression                 Enable Websocket compression (RFC 7692)