How to Plan Documentation for Verifiers

Effective verifier documentation is a critical component of any decentralized network's success. It directly impacts node uptime, protocol security, and the overall health of the ecosystem. This guide outlines a systematic approach to planning documentation that serves both novice operators and experienced developers. We'll cover defining your audience, structuring content for different user journeys, and incorporating essential technical details like RPC endpoints, consensus rules, and slashing conditions.

Start by mapping the verifier's lifecycle, from initial research to ongoing maintenance. Your documentation should have clear paths for: Installation & Setup, Configuration & Syncing, Operation & Monitoring, and Troubleshooting. For each stage, identify the key decisions an operator must make and the commands they need to run. For example, a setup guide must specify hardware requirements, the exact git clone and make install commands, and how to initialize the chain genesis or connect to a snapshot.

Incorporate real code snippets and configuration examples. Instead of just describing a flag, show the config.toml entry. Compare the trade-offs of different syncing modes (snapshot vs. fast-sync vs. archive). Use diagrams or clear prose to explain state transitions, like moving a node from a validator to a non-validating full node. Reference actual tools in the ecosystem, such as Prometheus for metrics or Grafana for dashboards, with links to their official documentation.

Finally, establish a maintenance and feedback loop. Document version-specific upgrade procedures, including hard fork migration steps. Create a changelog that highlights breaking changes for node operators. Encourage and document community contributions through a GitHub repository, using issues and pull requests to keep the guide accurate as the network evolves. This living document becomes the single source of truth, reducing support overhead and building a stronger, more self-sufficient operator community.

Before documenting a verifier, you must have a complete technical understanding of its core function. A verifier is a program that cryptographically validates the correctness of a computational proof, such as a zk-SNARK or zk-STARK. You need to document its specific proving system (e.g., Groth16, Plonk, Halo2), the circuits it verifies, and the public inputs it expects. This foundational knowledge is non-negotiable; you cannot explain a system you do not fully understand. Start by reviewing the verifier's source code, technical whitepapers, and any existing high-level architecture diagrams.

Next, identify and secure access to all necessary resources. This includes the verifier contract address on the target chain (e.g., 0x... on Ethereum Mainnet), the Application Binary Interface (ABI) for interacting with it, and the exact verification key used by the prover. You will also need a live environment for testing documentation steps, such as a testnet deployment or a local fork. Tools like Foundry or Hardhat are essential for this phase. Without these concrete artifacts, your documentation will lack the specific examples and verifiable instructions that developers require.

Finally, define the clear user personas and journeys for your documentation. Are you writing for an application developer integrating the verifier, a security auditor reviewing its code, or a protocol researcher understanding its mechanics? Each persona needs different information. Map out their journey from discovery to implementation: finding the contract, understanding the interface, generating a proof off-chain, calling the verify function, and handling the response. This planning ensures your documentation is structured to solve real problems, not just describe features.

Verifiers, including node operators, auditors, and security researchers, are a technically sophisticated audience. They require documentation that is precise, complete, and assumes a high level of competency in cryptography, distributed systems, and smart contract development. Unlike end-users, their primary goals are to validate protocol correctness, ensure operational security, and maximize performance. Your documentation must cater to these objectives with detailed specifications, configuration guides, and troubleshooting resources.

To plan effectively, segment your audience. A node operator needs step-by-step deployment guides, hardware requirements, and RPC endpoint management. An auditor requires in-depth protocol specifications, formal verification reports, and details on slashing conditions. A researcher looks for economic models, consensus algorithm proofs, and data availability schemas. Creating persona-based documentation paths ensures each user finds the technical depth they need without wading through irrelevant information.

Key content types for verifiers include: Architecture Deep Dives explaining the protocol's state machine and data flow, API & RPC References with exact request/response formats, Security Advisories detailing past vulnerabilities and patches, and Benchmarking Guides for testing node performance under load. Tools like Slither for static analysis or Grafana for monitoring should be referenced with specific configuration examples relevant to your protocol.

Incorporate real-world examples and edge cases. Instead of just listing a verifyProof() function, document the exact zk-SNARK circuit logic it checks or the Merkle proof format it expects. Provide annotated logs from mainnet incidents to illustrate failure modes. This level of specificity builds trust and utility, transforming your docs from a simple reference into an essential operational manual for maintaining network integrity.

The primary goal of verifier documentation is to enable independent parties to verify computational claims without executing the original program. Your code examples must be deterministic and self-contained. This means every operation, from cryptographic hash functions to random number generation, must be explicitly defined or seeded. Avoid dependencies on external APIs or non-deterministic system calls. For instance, when documenting a zk-SNARK verifier, your example should include the exact elliptic curve parameters (e.g., BN254 or BLS12-381), the proving key, and a concrete public input vector. Ambiguity here can lead to verification failures or, worse, security vulnerabilities.

Structure your examples to mirror the verification algorithm's logical flow. Start with data ingestion, showing how to parse the proof and public inputs. Next, demonstrate constraint system validation, which often involves pairing checks or polynomial evaluations. Finally, show the decision logic that outputs accept or reject. Use pseudocode or actual Solidity/Vyper snippets for on-chain verifiers, or Rust/Python for off-chain. For each step, annotate the code with comments explaining the cryptographic primitive being used, such as \"This performs the pairing check e(A, B) == e(C, D)\". Tools like the Circom compiler or SnarkJS have specific output formats that your examples must adhere to.

Incorporate test vectors and edge cases directly into the documentation. Provide a working example with a valid proof that should pass verification, and explicitly include another example with an invalid proof (e.g., a tampered public input) that must be rejected. This demonstrates the verifier's correctness and soundness. Document the exact library versions used (e.g., arkworks 0.4.0), as subtle changes in cryptographic libraries can break verification. For blockchain verifiers, specify the exact EVM opcode costs or gas usage estimates for each major operation, as this is critical for deployers. Planning with this level of specificity transforms your documentation from a simple guide into a reliable reference for auditors and implementers.

Begin by consolidating your research. Create a single source of truth, such as a Notion page or GitHub wiki, that links to all relevant resources: the official protocol documentation (e.g., Scroll's or zkSync's verifier guides), the canonical smart contract repository addresses, and your compiled notes on the specific proving system (e.g., PLONK, STARK) and its trusted setup ceremony. This repository becomes your primary reference point for all subsequent development and auditing work.

Next, map out the verifier's integration lifecycle. Define clear stages: 1) Environment Setup (installing necessary toolchains like Rust or Circom), 2) Local Testing (running the verifier against test vectors from the protocol), 3) Testnet Deployment (deploying and interacting with the verifier contract on a test network like Sepolia or Holesky), and 4) Mainnet Preparation (final security audit and governance proposal drafting). Assign realistic timelines and success criteria to each stage to track progress methodically.

Your technical documentation should evolve alongside the code. For each function in your verifier contract—such as the primary verifyProof entry point or auxiliary state management functions—maintain inline NatSpec comments. Use a tool like solidity-docgen to auto-generate a user-friendly API reference. Furthermore, create a separate operational guide covering key actions: how to update verification keys after a protocol upgrade, how to respond to a suspected bug or cryptographic vulnerability, and the process for submitting a verified batch to the L1 settlement contract.

Finally, plan for maintenance and community engagement. Verifier logic is not static; it must be updated for protocol upgrades and new security patches. Establish a monitoring system for announcements from the core development team. Consider open-sourcing your verifier implementation and documentation to foster peer review and contribute back to the ecosystem. The goal is to build a verifier that is not only functionally correct but also sustainable and transparent, forming a reliable piece of blockchain infrastructure.