Broadcasters & The RAILGUN Ecosystem: Gasless Private Transactions

So far I've covered how RAILGUN provides privacy through shielding, how zero-knowledge proofs make it possible, and how PPOI keeps it compliant. One practical problem is still open: how do you submit a private transaction to the blockchain without revealing who you are?

That's where Broadcasters come in. They're the final piece that makes RAILGUN private end to end.

The Metadata Problem

Even with perfect transaction privacy, submitting a transaction to the blockchain creates metadata. When you broadcast one yourself, your IP address is visible to the node you connect to, your public address pays the gas fees, and timing analysis can link transactions to specific users.

Say you shield tokens from address A, then immediately submit a private transaction from the same IP that owns address A. An observer can make a reasonable guess about who's behind the private activity.

RAILGUN's Broadcaster network solves this.

What Are Broadcasters?

Broadcasters are independent operators who submit transactions on behalf of RAILGUN users. Instead of broadcasting your transaction directly, you construct your private transaction and send it to a Broadcaster. The Broadcaster submits it to the blockchain and pays the gas, and you pay the Broadcaster a fee out of your private balance.

The key point is that the Broadcaster does the submitting, so the blockchain sees the Broadcaster's address and IP, not yours.

How Broadcaster Communication Works: Waku P2P

RAILGUN uses Waku, a decentralized peer-to-peer communication protocol, to connect users with Broadcasters. This choice is crucial for privacy.

Why not regular APIs or servers? Because those would be points of surveillance. A centralized Broadcaster API would know exactly who's using the service and when.

Waku avoids that in three ways. Discovery is decentralized: there's no central server listing Broadcasters, and the network itself handles discovery through peer-to-peer protocols. Communication is encrypted end to end, so the other peers relaying a message can't read it. And there's no central point of failure: if some Broadcasters go offline, others stay available and the network routes around the problem.

Technical Implementation: RAILGUN runs a self-federated network of nwaku nodes (the full Waku implementation, meant for resource-rich environments) that relay transactions. Wallet applications use js-waku, a lightweight implementation designed for browsers and desktop apps. Broadcasters advertise their fees through the network, and users pick the most appropriate one.

RAILGUN transactions use a dedicated communication topic on the Waku network, separate from other Waku traffic. That dedicated channel prevents congestion and keeps Broadcaster communication reliable.

Your wallet connects to the Waku network, finds available Broadcasters and negotiates with them privately. No central entity sees any of it.

Broadcaster Fee Structure

Broadcasters charge fees based on gas costs, not transaction amounts, and that distinction matters.

Fee Calculation: a Broadcaster charges a percentage premium on top of the overall gas price of the transaction. Whether you're sending $100 or $100,000, the fee stays roughly the same, because it's tied to gas rather than value.

Typical Markup: around 10% above base gas costs, though it varies with each Broadcaster's configuration and with network conditions.

Payment Method: fees come out of your private balance, in the token you're transacting with. Common fee tokens include WETH, DAI, USDC and other liquid assets. You never need to hold the chain's native token in your shielded address.

Privacy Preserved: the transaction content is encrypted in transit. A Broadcaster can't read the transaction details beyond the gas allocation packaged for its service. It never holds your tokens custodially and never sees the actual sender, receiver or amounts.

Your wallet automatically picks the Broadcaster with the best mix of low fees and high availability, though you can adjust that preference manually.

Self-Broadcasting: Maximum Decentralization

What if you don't want to rely on Broadcasters at all? RAILGUN supports self-broadcasting, where you run your own Broadcaster node and submit your own transactions.

That suits a few kinds of users. Power users who transact often can avoid Broadcaster fees. Privacy maximalists may not want any third party involved, even with the anonymity Broadcasters provide. And institutional users may have compliance requirements around how transactions get submitted.

The cost is that self-broadcasting means paying gas from your own public wallet, which creates some metadata. You can soften that by using a dedicated wallet just for gas, funding it through privacy-preserving means, and timing your transactions so they're hard to correlate.

For most users, regular Broadcasters strike a very good balance between convenience and privacy. Self-broadcasting is there for people who want complete control.

RAILGUN DeFi Integrations

Privacy is most valuable when you can actually use it, so RAILGUN plugs into the wider DeFi ecosystem through several mechanisms.

RAILGUN Connect

This is RAILGUN's interface for working with external DeFi protocols. Through it you can swap tokens on Uniswap, SushiSwap and other DEXs, provide liquidity to pools, use lending protocols, and run complex multi-step transactions, all while staying private. Your shielded address reaches these protocols through the RAILGUN contract, so the external protocol sees a transaction from RAILGUN, not from you.

Adapt Modules

RAILGUN has a modular architecture where new protocol integrations can be added without changing the core contract. Adapt Modules are the standardized interfaces that make this work. Each one defines how to interact with a specific external protocol, handles encoding and decoding the transaction data, and makes sure the transaction still meets the privacy requirements.

New integrations can be proposed and added through governance, so RAILGUN's capabilities grow over time.

Cross-Chain Operations

RAILGUN is deployed on Ethereum, Polygon, BSC and Arbitrum. Each deployment is independent, but you can move between chains by unshielding on Chain A, bridging with your preferred bridge, and shielding again on Chain B.

You lose some privacy during the bridge step. Still, many users have different privacy needs on different chains. You might want maximum privacy on Ethereum mainnet and be more relaxed on a cheaper chain for smaller transactions.

The RAIL Token and Governance

RAILGUN DAO governs the protocol through the RAIL token. Holders can vote on proposals such as protocol upgrades, parameter changes and treasury allocations. They can stake for rewards through the protocol's staking mechanisms, and they can join governance discussions on community forums and governance platforms.

The DAO controls the protocol fee rate (currently 0.25% on shields), how treasury funds are allocated, blocklist management for PPOI, and decisions about protocol upgrades.

That decentralized governance means no single entity controls RAILGUN's future.

The Complete Privacy Stack

Here's how all the pieces fit together, layer by layer.

Layer 1: Core Privacy is the cryptography. zk-SNARKs prove a transaction is valid without revealing its details, the UTXO model tracks private balances, Merkle Trees enable efficient membership proofs, and nullifiers prevent double spending.

Layer 2: Compliance sits on top of that. PPOI proves funds aren't from blocked sources, viewing keys enable selective disclosure, and recursive proofs carry innocence through every transaction.

Layer 3: Infrastructure gets transactions onto the chain. Broadcasters submit them anonymously, Waku P2P provides decentralized communication, and self-broadcasting is there for power users.

Layer 4: Ecosystem is what makes it useful. DeFi integrations expand what you can do, multi-chain deployment gives you options, and DAO governance keeps the whole thing decentralized.

Each layer builds on the ones below it, and together they make comprehensive privacy infrastructure.

Who Runs Broadcasters?

Anyone can run a Broadcaster node. The requirements are short:

• A server with decent uptime
• ETH (or native tokens) for gas on the chains you support
• The Broadcaster software

Broadcasters compete on reliability and fees. Those offering better service at competitive rates get more transaction volume, and that market dynamic pushes for efficiency and keeps fees reasonable.

The barrier to entry is intentionally low. More Broadcasters means more decentralization and better privacy for users.

Real-World Usage Patterns

Here's what this looks like in practice.

The Trader

A trader shields ETH and stablecoins and executes swaps through RAILGUN Connect, keeping the strategy private. When it's time to realize profits, they unshield to a fresh address. Competitors never see their moves.

The DAO Treasury

A DAO shields its treasury to protect against front-running and surveillance, and pays contributors privately. It can still give auditors viewing key access for accountability.

The Privacy-Conscious Individual

Someone who just wants their finances private shields their regular holdings, makes transfers to friends, and uses DeFi without every blockchain observer tracking them.

The Business

A company runs payroll and vendor payments through RAILGUN. Employee salaries stay confidential, and it uses PPOI proofs when dealing with regulated entities.

The Bottom Line

Broadcasters complete RAILGUN's privacy stack. Without them, submitting a transaction would leak metadata that undermines the cryptographic privacy. With them, submission is anonymous and your gas wallet is never exposed. The infrastructure is decentralized and censorship-resistant, and market competition keeps the fees down.

Combined with the core privacy technology, the compliance tools and the DeFi integrations, that makes RAILGUN a complete solution for on-chain privacy.

Wrapping Up the Series

Over these five articles I've gone through RAILGUN from top to bottom.

Article 1 introduced the problem of public blockchain surveillance and how RAILGUN brings privacy to DeFi without sacrificing security or decentralization.

Article 2 walked through the Shield and Unshield process, 0zk addresses and the fee structure.

Article 3 went into zero-knowledge proofs, explaining how zk-SNARKs, UTXOs and Merkle Trees create mathematically proven privacy.

Article 4 covered Private Proofs of Innocence, showing how RAILGUN balances privacy with compliance through recursive proofs and decentralized blocklists.

Article 5 completed the picture with Broadcasters, the Waku network and the broader ecosystem.

RAILGUN is a mature approach to blockchain privacy. It isn't about hiding from the world. It's about having the same financial privacy on-chain that we take for granted off-chain, while keeping the transparency options that legitimate use cases need.

Privacy isn't a feature. It's a right. RAILGUN makes that right practical on public blockchains.