How to run a FLOP devnet validator: step-by-step guide

Update, November 10, 2026: package 0.4.1-devnet.1 is out. The explorer now serves validator-cs-be91fe83 · 0.4.1-devnet.1 (last modified 11:32 UTC on November 9). We verified archive SHA-256 715abad72f3a8c658de5f929c6fe01b03d4204b5954925331766053610f3c967 against the published checksum file. Its only change: onboard join now waits up to five minutes for the node to serve RPC after its restart, fixing joins that ended with WS 1006 (our story). The validator manual still names 0.4.0-devnet.1.

Update, November 9, 2026: package 0.4.0-devnet.1 is out. The explorer and the validator manual now point to validator-cs-be91fe83 · 0.4.0-devnet.1. We verified archive SHA-256 95486a2b8c2471675a9c1b42ce0749aa8daeb11f2f9adaf5e9dee06ac085f7e5 against the published checksum file. Its changelog adds a join path for a validator-grant.json from operations and a pnpm onboard status report (our story). Onboarding is still administrator-assisted.

Update, November 7, 2026: package 0.3.0-devnet.1 is downloadable again. The explorer's validator page lists validator-cs-be91fe83 · 0.3.0-devnet.1 with working download and checksum links. We verified archive SHA-256 bf98e281b7d3217fb52e9aeba75886d2165e66d32f0159dbc3f1f2e998e30ba7 against the published checksum file (our story). Onboarding is still administrator-assisted; public testnet self-service is not open. Always verify the checksum before you extract.

Update, November 8, 2026: Flop's validator manual, updated November 6, says signed validator sponsorship requests "may auto-admit within the chain-backed sponsored count/stake caps" and that validators "no longer need the former sponsorship allowlist". Flop Labs said on November 7 it will expand the validator cap slowly. Live budgets are on our FLOP devnet limits page.

Host bills vs a draft seat: validator cost calculator. Live package status: testnet tracker. Official manuals and these tools in one list: best tools for FLOP validators.

Updated November 3, 2026. The FLOP devnet opened for builders on November 3. This guide follows Flop's validator manual (last updated October 30) and the explorer's Validate on FLOP page. We quote their commands and don't add any of our own. If the package README disagrees with this page, follow the README.

Devnet earns nothing. Flop's timeline FAQ says "No rewards, no airdrop weight, no scoring." Devnet FLOP has no value and the chain may be reset. FLOP never asks for your seed phrase. Check every link against flop.finance/official or our official links list.

What does a FLOP validator do?

The manual says validators "author blocks with BABE, vote on finality with AlephBFT, and serve assigned data through a DA worker. No GPU or TEE is needed." Validators keep the chain running. GPU work is the miner's job.

Is devnet validator onboarding self-service?

No. The explorer labels it "Administrator-assisted devnet onboarding", and FLOP operations takes part at each stage. The manual says "Self-service public testnet onboarding" is "still in progress". Selecting testnet in a command won't get you there.

The docs don't name a contact for FLOP operations. The public route we found is Flop's validator interest form, which asks whether you plan to join at testnet or mainnet and how many validators you want to run.

What server do I need?

You need what the manual calls a "dedicated Linux amd64 host". It asks for these tools on the machine:

• Docker Engine and the Docker Compose plugin
• curl and jq
• Node.js and pnpm "matching the repository's pinned toolchain"

Flop has published two hardware profiles, and they don't match:

Source	CPU	RAM	Storage	Network
Validator manual, production planning	8 dedicated cores	32 GB	4 TB NVMe including DA custody	Reliable low-latency 1 Gbps
flop.finance/testnet, provisional	8+ cores	64 GB	4 TB NVMe (2 TB minimum)	1 Gbps redundant

The manual calls its figures "planning estimates, not measured devnet minimums". If you're buying hardware for the testnet, the stricter column (64 GB RAM, 4 TB NVMe) covers both.

What does a validator server cost?

As a cost reference, here are two Hetzner dedicated servers. Prices below come from Hetzner's price adjustment notice of June 15, 2026, for its Falkenstein and Helsinki sites, excluding VAT and IPv4. Specs come from Hetzner's product pages.

Server	Monthly	Setup fee	RAM	Storage	Port
AX42	€97.30	€49	64 GB DDR5 ECC	2 x 512 GB NVMe	1 Gbit/s
AX102	€257.30	€129	128 GB DDR5 ECC	2 x 1.92 TB NVMe	1 Gbit/s

The AX42's base storage adds up to 1 TB, half of Flop's 2 TB minimum, so the base configuration falls short. The AX102's two drives add up to 3.84 TB, still short of the 4 TB planning profile, and mirroring them halves that. Hetzner's AX102 page lists drives up to 2 x 7.68 TB. Price your build with the extra storage before you order.

We checked these pages on November 3. Hetzner's notice URL returned a 404 for us that day, so confirm prices in Hetzner's order page before you pay.

Step 1: Download and check the package

The explorer's validator page lists the current package as "validator-cs-be91fe83 · 0.4.1-devnet.1 · FLOP Devnet · Linux amd64". On November 10 the download and SHA-256 links both returned HTTP 200 for us, and the archive matched 715abad72f3a8c658de5f929c6fe01b03d4204b5954925331766053610f3c967. The 0.4.0-devnet.1 archive matched 95486a2b8c2471675a9c1b42ce0749aa8daeb11f2f9adaf5e9dee06ac085f7e5 on November 9. The previous 0.3.0-devnet.1 archive matched bf98e281b7d3217fb52e9aeba75886d2165e66d32f0159dbc3f1f2e998e30ba7 on November 7. On November 4 the older 0.2.0-devnet.1 links had returned 404. Download only a package the explorer lists with its checksum, and verify it before extract.

The manual says the package "includes pinned images, the raw chain spec, peer details and local setup helpers. No private repository access is required." Check the download against the checksum file before you go further. Then follow the package README.

Step 2: Prepare and send public host details

The manual lists the commands in this order:

1. Verify the package checksums.
2. Install dependencies: pnpm install --frozen-lockfile --ignore-scripts
3. Prepare the host: pnpm onboard prepare
4. Send FLOP operations the printed hostname, public SS58 address, and host SSH public key (/etc/ssh/ssh_host_ed25519_key.pub), as the current package README describes.

"Private account files and keys stay on your host." Nobody at FLOP needs your seed or private keys. Anyone who asks for them is not FLOP.

Step 3: Get network access and funding, then join

FLOP operations replies with Tailscale enrollment instructions. It also funds your account "above the live minimum with surplus for fees and DA deposits". Wait until both are confirmed, then run:

pnpm onboard join

Then tell operations you're ready. The manual says the command "waits for sync, registers with owner-bound keys, and restores safe loopback RPC before reporting ready."

Registration locks stake. The manual says: "Stop and contact operations after a failed/partial submission; do not blindly rerun signed actions."

Step 4: Wait for activation, then verify

Operations reads your registration, public session keys, queue position and DA endpoint from finalized chain state. It also checks your host's connectivity before promotion. "You do not send keys, transaction hashes or configuration."

Once operations confirms activation, run this against your own node:

pnpm onboard verify

The manual warns: "“Ready” does not mean active: session/BABE/Aleph keys and advancing finality must be verified." Registration alone only puts your account in the queue.

Which ports does the package use?

From the manual: "The package uses tailnet P2P TCP 30333 and DA TCP 7001; RPC 9944 and metrics 9615 remain on loopback." Keep RPC and metrics off the public internet.

How do I keep a validator safe?

The manual's host rules, in its words:

• Protect the host and backups "with encrypted storage and key-only SSH".
• Give each validator "its own persistent volumes and session keys".
• "Never run two active processes with the same session keys: simultaneous voting can equivocate."
• Back up "the account seed, node keystore and persistent volume, libp2p node key, and DA worker data with controlled access", and test restoration offline.
• "Never put a private account or root seed into an issue, chat, command log, or shared shell history."

For upgrades, Flop points existing validators to its upgrade manual.

What about the public testnet?

The manual describes a prepared testnet profile. pnpm onboard prepare --profile administrator-assisted-devnet keeps today's assisted flow. A read-only check, pnpm onboard preflight --profile public-testnet, "fails closed" until Flop publishes the network identity and other inputs. "The next package is unpublished." Flop targets the testnet for November 24, 2026, subject to readiness (our story), and genesis validators are picked on testnet performance (how FLOP validators are selected). For dates and requirements, see our FLOP testnet hub and validator guide.

FAQ

Do I need a GPU to run a FLOP devnet validator?

No. Flop's validator manual says "No GPU or TEE is needed." You need a dedicated Linux amd64 host with Docker Engine, the Compose plugin, curl, jq, Node.js and pnpm.

Does running a devnet validator count for the FLOP airdrop?

No. Flop's timeline FAQ says the devnet earns nothing: no rewards, no airdrop weight and no scoring. Running a devnet validator is practice for the testnet, which the FAQ names as the first network where anyone can earn.

Can I join as a validator without FLOP operations?

Not on today's devnet. The explorer calls onboarding administrator-assisted. Operations gives you Tailscale access, funds your account and promotes it. Self-service public testnet onboarding was still in progress on November 3, 2026.

What happens if pnpm onboard join fails?

Stop and contact operations. Registration locks stake, and the manual says not to blindly rerun signed actions after a failed or partial submission.

How much does a FLOP validator server cost?

At Hetzner's June 2026 prices, an AX42 costs €97.30 a month plus a €49 setup fee, and an AX102 costs €257.30 a month plus €129, both excluding VAT. Both need extra storage to reach the 4 TB NVMe planning profile.