Local DA

Local DA is a development-only data availability layer for testing Evolve chains without connecting to a real DA network.

Overview

Local DA provides:

• Fast, local blob storage
• No authentication required
• No gas fees
• Instant "finality"

Warning: Local DA is for development only. It provides no actual data availability guarantees.

Installation

Install the local-da binary:

go install github.com/evstack/ev-node/tools/local-da@latest

Or build from source:

cd ev-node/tools/local-da
go build -o local-da .

Running Local DA

Start the local DA server:

local-da

Default output:

INF NewLocalDA: initialized LocalDA module=local-da
INF Listening on host=localhost maxBlobSize=1974272 module=da port=7980
INF server started listening on=localhost:7980 module=da

Configuration

Flag	Default	Description
--host	localhost	Listen address
--port	7980	Listen port

Example with custom port:

local-da --port 8080

Connecting Your Chain

Start your Evolve chain with the local DA address:

evnode start \
    --evnode.node.aggregator \
    --evnode.da.address http://localhost:7980

For Cosmos SDK chains:

appd start \
    --evnode.node.aggregator \
    --evnode.da.address http://localhost:7980

Features

No Authentication

Unlike Celestia, local DA requires no auth token:

# Celestia requires
--evnode.da.auth_token <token>

# Local DA does not
--evnode.da.address http://localhost:7980

No Namespace Required

Namespace is optional with local DA:

# Optional
--evnode.da.namespace my_namespace

Instant Submission

Blobs are stored immediately with no block time delay.

Use Cases

Local Development

Test your chain logic without DA layer complexity:

# Terminal 1: Start local DA
local-da

# Terminal 2: Start your chain
evnode start --evnode.da.address http://localhost:7980

CI/CD Testing

Use local DA in automated tests:

# Start local DA in background
local-da &
LOCAL_DA_PID=$!

# Run tests
go test ./...

# Cleanup
kill $LOCAL_DA_PID

Integration Testing

Test multi-node setups locally:

# Start local DA
local-da --port 7980

# Start sequencer
evnode start \
    --evnode.node.aggregator \
    --evnode.da.address http://localhost:7980 \
    --evnode.p2p.listen /ip4/0.0.0.0/tcp/7676

# Start full node (separate terminal)
evnode start \
    --evnode.da.address http://localhost:7980 \
    --evnode.p2p.peers /ip4/127.0.0.1/tcp/7676/p2p/<sequencer-peer-id>

Limitations

Local DA is not suitable for:

• Production deployments
• Security testing
• Performance benchmarking (no real network latency)
• Testing DA-specific features (proofs, commitments)

Transitioning to Celestia

When ready for production, switch to Celestia:

1. Set up a Celestia light node
2. Update your start command:

# From local DA
--evnode.da.address http://localhost:7980

# To Celestia
--evnode.da.address http://localhost:26658
--evnode.da.auth_token $AUTH_TOKEN
--evnode.da.header_namespace $HEADER_NAMESPACE
--evnode.da.data_namespace $DATA_NAMESPACE

See Celestia Guide for full instructions.

See Also

• Celestia Guide - Production DA setup
• EVM Quickstart - Getting started with EVM
• Cosmos Quickstart - Getting started with Cosmos SDK