Celestia Mocha-5 Light Node

A light node follows extended headers and performs data availability sampling (DAS) without downloading every block. Current celestia-node DA roles are bridge and light only.

Operational scope and Fibre boundary

Informational guide: POSTHUMAN does not operate a Celestia Bridge or Light node. The templates below describe a separately approved deployment, not existing POSTHUMAN infrastructure. Updating this guide enables no service, port, firewall rule, key, escrow, or transaction.

v0.34.2-mocha adds a built-in Fibre client and the fibre JSON-RPC namespace on Bridge and Light nodes. The namespace includes Submit, Upload, Download, Deposit, Withdraw, QueryEscrowAccount, and PendingWithdrawals. Fibre needs a configured Mocha core endpoint running celestia-app v10 with x/fibre and x/valaddr; it is unavailable without a core endpoint. Installing a v10 wrapper before activation does not mean these v10 modules are active.

The Mocha-5 app target is v10.2.0-mocha, activation height 1082619; see App upgrade and rollback boundaries. This is not a mainnet version recommendation. Fibre/escrow activation requires a separate operator decision covering custody, funding, exposure and provider dependencies. Do not call Submit/Upload/Deposit/Withdraw, fund escrow, enable signer gRPC, or infer Fibre availability from DA health checks in this guide.

Network and software pins

• Consensus chain ID: mocha-5
• DA P2P network: mocha
• celestia-node: v0.34.2-mocha
• Source commit: cd6cd46f00a572a7010fecc7e0dacf8a456982d2
• Go: 1.26.8
• Store: $HOME/.celestia-light-mocha-5

Mocha-5 is a new chain from height 1. Never reuse a Mocha-4 DA store, consensus data directory, or signer-state file. Do not install from an unpinned branch or pipe a remote script into a shell.

Capacity

Profile	CPU	Memory	Disk	Network
Pruned light node	1 core	500 MB	20 GB SSD	56 Kbps
Unpruned-header light node	1 core	500 MB	7 TiB NVMe	56 Kbps

The 20 GB profile is for normal pruned operation. The 7 TiB figure is a one-year planning estimate for unpruned headers at the 128 MB per 6 seconds maximum-throughput envelope. Monitor actual growth and keep capacity headroom.

Build from the pinned source

Install Go 1.26.8 and build dependencies through trusted distribution channels, then verify the toolchain.

go version
test "$(go env GOVERSION)" = "go1.26.8"

NODE_TAG="v0.34.2-mocha"
NODE_COMMIT="cd6cd46f00a572a7010fecc7e0dacf8a456982d2"
BUILD_ROOT="$(mktemp -d -p /tmp celestia-node-build.XXXXXX)"

git clone --filter=blob:none --depth 1 --branch "$NODE_TAG" \
  https://github.com/celestiaorg/celestia-node.git "$BUILD_ROOT/src"
test "$(git -C "$BUILD_ROOT/src" rev-parse HEAD)" = "$NODE_COMMIT"

make -C "$BUILD_ROOT/src" build cel-key
install -d "$BUILD_ROOT/stage/bin"
install -m 0755 "$BUILD_ROOT/src/build/celestia" \
  "$BUILD_ROOT/stage/bin/celestia"
install -m 0755 "$BUILD_ROOT/src/cel-key" \
  "$BUILD_ROOT/stage/bin/cel-key"

"$BUILD_ROOT/stage/bin/celestia" version

Keep staging until the reported version and commit are reviewed. For a new, non-running node, install the reviewed staged binaries at $HOME/.local/bin/. Binary activation and service restart are separate approval-controlled steps.

Initialize a new Mocha-5 store

Verify the proposed consensus endpoint reports mocha-5. Add --core.tls only when the endpoint supports TLS.

celestia-appd status --node <consensus-rpc-url> | \
  jq -e '.NodeInfo.network == "mocha-5"'

"$HOME/.local/bin/celestia" light init \
  --node.store "$HOME/.celestia-light-mocha-5" \
  --core.ip <mocha-5-consensus-grpc-host> \
  --core.port <grpc-port> \
  --core.tls \
  --p2p.network mocha

Initialization creates a new DA store and local keyring. Do not copy a Mocha-4 directory into it. Follow Keys and signer boundaries.

Keep JSON-RPC 26658 on loopback unless an authenticated, TLS-protected, rate-limited access layer is explicitly designed and reviewed.

Service template

[Unit]
Description=Celestia Mocha-5 light node
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=<service-user>
ExecStart=%h/.local/bin/celestia light start --node.store %h/.celestia-light-mocha-5 --core.ip <mocha-5-consensus-grpc-host> --core.port <grpc-port> --core.tls --p2p.network mocha
Restart=on-failure
RestartSec=5
LimitNOFILE=65535

[Install]
WantedBy=multi-user.target

This guide does not submit blobs or other transactions.

Verify

systemctl is-active celestia-light-mocha-5.service
"$HOME/.local/bin/celestia" header sync-state \
  --node.store "$HOME/.celestia-light-mocha-5"
"$HOME/.local/bin/celestia" p2p info \
  --node.store "$HOME/.celestia-light-mocha-5"
"$HOME/.local/bin/celestia" state account-address \
  --node.store "$HOME/.celestia-light-mocha-5"
ss -lntp | grep ':26658'
journalctl -u celestia-light-mocha-5.service \
  --since "15 minutes ago" --no-pager

Healthy means the service remains stable, headers advance toward an independent Mocha-5 reference, sampling has no persistent errors, peers are present, RPC is loopback-bound, and disk has headroom. Any Mocha-4 chain identity is a hard failure; stale or unknown freshness is degraded.

Upgrade discipline

Build replacements in a new staging directory, verify the announced Mocha tag and commit, retain rollback, and activate only after review. When upgrading from before v0.31.3, run celestia light config-update --p2p.network mocha --node.store "$HOME/.celestia-light-mocha-5" while stopped and inspect the merged configuration before activation.

Sources

Release and toolchain reviewed 2026-09-23:

• Official v0.34.2-mocha release, Fibre namespace and core v10 dependency
• Pinned celestia-node go.mod (Go 1.26.8)

Capacity and general role guidance below retain their historical documentation provenance; they are not a new benchmark of Fibre workloads.

Evidence reviewed from the official Celestia docs repository at commit 8fbaa868a323c13d3edae2875d9b27765eb29c45:

• operate/getting-started/hardware-requirements
• operate/data-availability/light-node/quickstart
• operate/data-availability/light-node/advanced
• operate/data-availability/install-celestia-node
• operate/networks/mocha-testnet