Local Development

This page documents the canonical local single-node workflow for c8ntinuum developers.

Canonical script

local_node.sh is at the root of the ctmd node source repository and is the canonical local-node script. The node source will be published in a public GitHub repository (repository TBA); the commands on this page run from the root of that repository:

./local_node.sh [options]

There is no separate local-node repository for the default developer flow. For hosted deployment scripts and source attribution, see Deployment Scripts.

Prerequisites

Go matching go.mod
make
jq
A working C toolchain for CGO builds
Rust/SP1 build dependencies required by make install

local_node.sh installs ctmd by default with make install. The install directory is BINDIR if set, otherwise $GOPATH/bin when GOPATH is set, otherwise $HOME/go/bin. The script then runs whichever ctmd comes first on your PATH.

Install and start

Start from a clean local genesis and install the binary:

./local_node.sh -y

Use an existing installed binary without rebuilding:

./local_node.sh --no-install -y

Install into a custom binary directory and run that binary. Put the directory first on PATH, because the script runs the first ctmd it finds there:

BINDIR=/tmp/ctm-bin PATH="/tmp/ctm-bin:$PATH" ./local_node.sh -y

Start the existing local node state without overwriting ~/.ctmd:

./local_node.sh --no-install -n

The script writes local chain data under:

$HOME/.ctmd

Reset

The normal reset command is:

./local_node.sh -y

That removes the existing $HOME/.ctmd directory and creates a fresh local genesis. The manual equivalent is:

rm -rf "$HOME/.ctmd"
./local_node.sh

Stop the node with Ctrl-C.

Useful flags

-y                       Overwrite existing chain data without prompt
-n                       Do not overwrite existing chain data
--no-install             Skip 'make install'
--remote-debugging       Build with nooptimization,nostrip
--additional-users N     Create N extra users: dev4, dev5, ...
--mnemonic-file PATH     Where to write mnemonics YAML
--mnemonics-input PATH   Read dev mnemonics from a yaml file

--additional-users accepts only non-negative integers. Generated extra-user mnemonics are written to $HOME/.ctmd/mnemonics.yaml unless --mnemonic-file is provided.

Chain configuration

The local chain uses Cosmos chain ID c8ntinuum_8888888-1 and EVM chain ID 8888888, distinct from mainnet (c8ntinuum_8-1, EVM 8) and testnet (c8ntinuum_8888-1, EVM 8888). The script sets the EVM chain ID explicitly: a node started without it uses ctmd’s default of 8, the mainnet ID, and EVM transactions signed on it are valid on mainnet. Never use a key that holds real funds on a local chain.

Setting	Local value
Cosmos chain ID	`c8ntinuum_8888888-1`
EVM chain ID	`8888888` / `0x87a238`
Native denom	`atest`
Currency symbol	`TEST`
Keyring backend	`test`
Account key algorithm	`eth_secp256k1`
Node home	`$HOME/.ctmd`
Moniker	`localtestnet`
Minimum gas price	`0atest`
EVM min tip	`0`
EVM JSON-RPC APIs	`eth,txpool,personal,net,debug,web3`

For EVM tooling and wallets, use chain ID 8888888 (0x87a238) and confirm it with eth_chainId after startup.

Ports

The script enables the local app APIs and uses the default ctmd local addresses.

Service	Default local address
EVM JSON-RPC HTTP	`http://127.0.0.1:8545`
EVM JSON-RPC WebSocket	`ws://127.0.0.1:8546`
CometBFT RPC	`tcp://127.0.0.1:26657`
CometBFT P2P	`tcp://127.0.0.1:26656`
Cosmos REST API	`tcp://127.0.0.1:1317`
Cosmos gRPC	`localhost:9090`
Geth metrics	`127.0.0.1:8100`

Default accounts

These accounts are deterministic local development accounts. They are public test keys and must never be used with real funds.

Name	EVM address	Local bech32 address	Private key
`dev0`	`0xC6Fe5D33615a1C52c08018c47E8Bc53646A0E101`	`c81cml96vmptgw99syqrrz8az79xer2pcgpw8hsl4`	`0x88cbead91aee890d27bf06e003ade3d4e952427e88f88d31d61d3ef5e5d54305`
`dev1`	`0x963EBDf2e1f8DB8707D05FC75bfeFFBa1B5BaC17`	`c81jcltmuhplrdcwp7stlr4hlhlhgd4htqhc0gcnx`	`0x741de4f8988ea941d3ff0287911ca4074e62b7d45c991a51186455366f10b544`
`dev2`	`0x40a0cb1C63e026A81B55EE1308586E21eec1eFa9`	`c81gzsvk8rruqn2sx64acfsskrwy8hvrmaffytl6p`	`0x3b7955d25189c99a7468192fcbc6429205c158834053ebe3f78f4512ab432db9`
`dev3`	`0x498B5AeC5D439b733dC2F58AB489783A23FB26dA`	`c81fx944mzagwdhx0wz7k9tfztc8g3lkfk62373ee`	`0x8a36c69d940a92fcea94b36d0f2928c7a0ee19a90073eda769693298dfa9603b`

Each default dev account receives:

1000000000000000000000atest

That is 1,000 TEST: the local denom is atest, with 18 decimals. The default validator key is mykey.

Field	Value
EVM/operator bytes	`0x7cB61D4117AE31a12E393a1Cfa3BaC666481D02E`
Local account address	`c810jmp6sgh4cc6zt3e8gw05wavvejgr5pwmph94z`
Local validator address	`c8valoper10jmp6sgh4cc6zt3e8gw05wavvejgr5pwrxmh56`
Mnemonic	`gesture inject test cycle original hollow east ridge hen combine junk child bacon zero hope comfort vacuum milk pitch cage oppose unhappy lunar seat`

The validator account is funded with 100000000000000000000000000atest during genesis, and its genesis transaction self-delegates 888888000000000000000000atest with --min-self-delegation 888888000000000000000000. That is 888,888 TEST, the self-delegation floor that x/msdcheck enforces.

Active precompiles and local native wrapper

local_node.sh activates this static precompile set in genesis:

Name	Address
P256	`0x0000000000000000000000000000000000000100`
Bech32	`0x0000000000000000000000000000000000000400`
Staking	`0x0000000000000000000000000000000000000800`
Distribution	`0x0000000000000000000000000000000000000801`
ICS20	`0x0000000000000000000000000000000000000802`
Bank	`0x0000000000000000000000000000000000000804`
Gov	`0x0000000000000000000000000000000000000805`
Slashing	`0x0000000000000000000000000000000000000806`
ICS02	`0x0000000000000000000000000000000000000807`

The script also configures the native ERC-20 precompile/token pair for the local denom:

Name	Address	Denom
Native ERC-20 / WERC20-style surface	`0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE`	`atest`

A fresh local genesis also includes the default preinstall set described in Pre-deployed Contracts: ctmd init writes it into the EVM genesis state, and the script does not remove it.

Docker support

The canonical local development path is ./local_node.sh. Docker assets exist, but they are separate from the single-node script flow:

contrib/images/ctmd-env/Dockerfile builds a ctmd environment image.
docker-compose.yml defines a four-node cosmos/ctmd localnet (ctmdnode0 to ctmdnode3).
tests/jsonrpc/Dockerfile and tests/jsonrpc/docker-compose.yml support the JSON-RPC test infrastructure.

Use Docker for workflows that explicitly reference those files. For day-to-day local development against the node source, prefer ./local_node.sh.

Expected logs

On a fresh reset, expect logs like:

Flag -y passed -> Overwriting the previous chain data.
using default mnemonics
adding key for dev0
adding key for dev1
adding key for dev2
adding key for dev3
Genesis transaction written to "$HOME/.ctmd/config/gentx/..."
File at $HOME/.ctmd/config/genesis.json is a valid genesis file
INF starting ABCI with CometBFT
INF starting node with ABCI CometBFT in-process
INF Starting JSON-RPC server address=127.0.0.1:8545
INF finalized block height=1
INF executed block height=1
INF committed state height=1

During shutdown with Ctrl-C, expect:

INF caught signal signal=interrupt
INF stopping gRPC server...
INF stopping API server...
INF stopping JSON-RPC server...
INF Application gracefully shutdown

Introduction

Developer Essentials

Tooling and Infrastructure

Reference

Guides

Resources

Canonical script

Prerequisites

Install and start

Reset

Useful flags

Chain configuration

Ports

Default accounts

Active precompiles and local native wrapper

Docker support

Expected logs

​Canonical script

​Prerequisites

​Install and start

​Reset

​Useful flags

​Chain configuration

​Ports

​Default accounts

​Active precompiles and local native wrapper

​Docker support

​Expected logs

Canonical script

Prerequisites

Install and start

Reset

Useful flags

Chain configuration

Ports

Default accounts

Active precompiles and local native wrapper

Docker support

Expected logs