Agent skill

Validate Config

Reviews an existing Diffyscan YAML or JSON config for load errors, runtime prerequisites, pinned sources, address mappings and broad exceptions.

MITAuto-check passedBackend & APIs

Install Validate Config

skills CLI

$ npx skills add lidofinance/diffyscan --skill validate-config -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install lidofinance/diffyscan validate-config --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/lidofinance/diffyscan.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/validate-config .claude/skills/validate-config && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "validate-config" agent skill from https://github.com/lidofinance/diffyscan/tree/main/.claude/skills/validate-config into .claude/skills/validate-config/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "validate-config", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/lidofinance/diffyscan/tree/main/.claude/skills/validate-config

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add lidofinance/diffyscan --skill validate-config -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install lidofinance/diffyscan validate-config --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lidofinance/diffyscan.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/validate-config .agents/skills/validate-config && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "validate-config" agent skill from https://github.com/lidofinance/diffyscan/tree/main/.claude/skills/validate-config into .agents/skills/validate-config/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "validate-config", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add lidofinance/diffyscan --skill validate-config -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install lidofinance/diffyscan validate-config --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lidofinance/diffyscan.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/validate-config .cursor/skills/validate-config && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "validate-config" agent skill from https://github.com/lidofinance/diffyscan/tree/main/.claude/skills/validate-config into .cursor/skills/validate-config/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "validate-config", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/lidofinance/diffyscan.git --path .claude/skills/validate-config

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add lidofinance/diffyscan --skill validate-config -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install lidofinance/diffyscan validate-config --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lidofinance/diffyscan.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/validate-config .gemini/skills/validate-config && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "validate-config" agent skill from https://github.com/lidofinance/diffyscan/tree/main/.claude/skills/validate-config into .gemini/skills/validate-config/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "validate-config", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install lidofinance/diffyscan validate-config

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add lidofinance/diffyscan --skill validate-config -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/lidofinance/diffyscan.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/validate-config .github/skills/validate-config && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "validate-config" agent skill from https://github.com/lidofinance/diffyscan/tree/main/.claude/skills/validate-config into .github/skills/validate-config/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "validate-config", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add lidofinance/diffyscan --skill validate-config -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install lidofinance/diffyscan validate-config --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/lidofinance/diffyscan.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/validate-config .opencode/skills/validate-config && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "validate-config" agent skill from https://github.com/lidofinance/diffyscan/tree/main/.claude/skills/validate-config into .opencode/skills/validate-config/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "validate-config", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: validate-config
GitHub stars: 142
Token cost: ~1.1k tokens
SKILL.md length: 478 words
Files: 1
Skills in repo: 5
Repo updated: Oct 6, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Reviews an existing Diffyscan YAML or JSON config for load errors, runtime prerequisites, pinned sources, address mappings and broad exceptions.

Works in 3 steps: Load and inspect → Review overrides and exceptions → Report
Preflight validation
SKILL.md covers 1. Load and inspect, 2. Review overrides and… and 3. Report
Calls uv

What it does

Validate Config is an agent skill from lidofinance/diffyscan. Reviews an existing Diffyscan YAML or JSON config for load errors, runtime prerequisites, pinned sources, address mappings and broad exceptions. Use for config review or preflight validation; failed live runs belong to debug-diff and new deployment setup to new-config.

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Backend & APIs, covering Smart contracts and Deployment. It works with Solidity. The repository describes itself as: Diffyscan detects deployment drift by comparing GitHub source with explorer-verified source and on-chain bytecode across EVM networks. The licence is MIT.

When your agent uses it

Preflight validation
Failed live runs belong to debug-diff and new deployment setup to new-config

Example prompts

“Use the validate-config skill to review an existing Diffyscan YAML or JSON config for load errors, runtime prerequisites, pinned sources, address…”
“/validate-config”

Requirements

Python 3

Workflow steps

3 steps, taken from the step headings in SKILL.md.

Load and inspect
Review overrides and exceptions
Report

What it can do on your machine

Read from SKILL.md and the folder at commit 9fd6833. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- uv
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use uv, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Validate Config loads about 1.1k tokens when it runs. Until then it costs about 71 tokens; SKILL.md has 478 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~71
When it runs · the whole SKILL.md, loaded when a task matches: ~1.1k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from lidofinance/diffyscan at commit 9fd6833, republished under its MIT licence (© lidofinance). 478 words, ~1,105 tokens.

Download SKILL.mdSave it as .claude/skills/validate-config/SKILL.md (or your agent's skills folder).

name: validate-config
description: Reviews an existing Diffyscan YAML or JSON config for load errors, runtime prerequisites, pinned sources, address mappings and broad exceptions. Use for config review or preflight validation; failed live runs belong to debug-diff and new deployment setup to new-config.
argument-hint: [config-path]

Validate the requested config without claiming static checks prove a deployment matches. Run commands from the repository root.

1. Load and inspect

Read the config, configuration reference, diffyscan/utils/common.py and diffyscan/utils/custom_types.py. TypedDicts describe structure; they do not enforce it at runtime. Check the actual loader:

uv run python - path/to/config.yaml <<'PY'
import sys
from diffyscan.utils.common import load_config
load_config(sys.argv[1])
print("Config load passed")
PY

Then inspect what the loader does not fully validate:

Nonempty contracts, string names and valid 20-byte hexadecimal addresses. Quote YAML hex keys and values, including nested overrides.
github_repo and each dependency have url, a full commit SHA and relative_root. Dependency prefixes match published source paths. Repository config tests require dependencies, including when empty.
An explicit explorer hostname or explorer_hostname_env_var; the runtime resolves the latter when the explicit hostname is absent. network, audit_url and metadata are optional descriptive fields.
get_explorer_chain_id in diffyscan/utils/explorer.py converts the configured value with int(). Check that it identifies the intended chain; conversion alone does not validate a chain ID. Confirm the API and RPC agree; the CLI does not compare their chain IDs.
Credential variable names and availability without printing values. Explorer token fallback is supported; an omitted token variable name is not inherently invalid. A token value is loaded even for adapters that do not send it.
Boolean flags and enabled comparisons. source_comparison: false combined with --skip-binary-comparison is rejected.

2. Review overrides and exceptions

Read bytecode comparison. Cross-check per-contract keys against contracts; flag unused entries. Preserve exact address spelling for constructor_args and constructor_calldata: their runtime lookup is case-sensitive, unlike allowed-diff rules. Check calldata hex, argument list shapes, mutually exclusive constructor overrides, deployment_from addresses and extra_sources paths. Library keys identify the definition file and apply to all contracts in the config.

load_config validates allowed_diffs through diffyscan/utils/allowed_diffs.py. Schema validity does not justify a rule: inspect reason and scope. Use allowed-diffs when tightening or adding exceptions.

Show full SKILL.md (187 more words)Show less

With bytecode comparison enabled, fail_on_bytecode_comparison_error: false lets outer per-contract errors continue, including explorer/source errors. With --skip-binary-comparison, that config flag is not applied. Caught bytecode errors produce failed results, except that a bytecode any: true rule marks DeploymentSimulationError as allowed.

For changes under configs/, run:

uv run pytest -q tests/test_configs.py tests/test_no_wildcard_regression.py

These tests inspect repository configs, not arbitrary files outside configs/. Loader success alone does not cover all schema fields, source availability, compiler reproduction or on-chain correctness.

3. Report

List concrete errors with config keys and locations, then evidence gaps or recommendations. Separate loader success, repository tests and live verification. If live verification was requested, run it with --json and inspect status, errors and coverage using JSON output; otherwise report the static verdict and its limits. Edit the config only when the task includes fixes.

Treat placeholder-looking addresses and commits as unverified inputs, not proof that a fetch will fail. An empty dependencies map is not an error without evidence of unresolved imports: those sources may belong to the primary repository. Report supported defaults as defaults rather than missing-field findings, and keep a review-only answer focused on findings instead of rewriting a valid config.

Files

Just SKILL.md in .claude/skills/validate-config of lidofinance/diffyscan.

Open the folder on GitHubat commit 9fd6833

Compare with similar skills

Validate Config next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Validate Config compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Validate Config this skilllidofinance/diffyscan	142	—	~1.1k	Automated safety check: Pass	MIT	2 days ago
Foundry Deploy Fixturesaviggiano/security	144	—	~634	Automated safety check: Pass	MIT	23 days ago
function Object() { [native code] } Patternsccashwell/evm-cortex	131	—	~1.7k	Automated safety check: Pass	MIT	8 days ago
Test Fixturesccashwell/evm-cortex	131	—	~1.9k	Automated safety check: Pass	MIT	8 days ago
Foundry Differential Testsaviggiano/security	144	—	~613	Automated safety check: Pass	MIT	23 days ago
Cross Chain Securityccashwell/evm-cortex	131	—	~1.7k	Automated safety check: Pass	MIT	8 days ago

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Questions about Validate Config

What does Validate Config do?

Reviews an existing Diffyscan YAML or JSON config for load errors, runtime prerequisites, pinned sources, address mappings and broad exceptions. Validate Config is an agent skill from lidofinance/diffyscan. Reviews an existing Diffyscan YAML or JSON config for load errors, runtime prerequisites, pinned sources, address mappings and broad exceptions.

When should I use Validate Config?

Validate Config fits situations like: preflight validation; failed live runs belong to debug-diff and new deployment setup to new-config.

How do I install Validate Config in Claude Code?

Run `npx skills add lidofinance/diffyscan --skill validate-config -a claude-code`. Or copy the skill folder (.claude/skills/validate-config in lidofinance/diffyscan) into .claude/skills/validate-config in your project. Claude Code loads it when a task matches its description.

How do I install Validate Config in Codex?

Run `npx skills add lidofinance/diffyscan --skill validate-config -a codex`. Or copy the skill folder (.claude/skills/validate-config in lidofinance/diffyscan) into .agents/skills/validate-config in your project. Codex loads it when a task matches its description.

Can I use Validate Config in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add lidofinance/diffyscan --skill validate-config -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/validate-config, .gemini/skills/validate-config, .github/skills/validate-config and .opencode/skills/validate-config in your project.

What does Validate Config need to run?

Going by SKILL.md and its folder, Validate Config needs the command-line tools its instructions call (uv). Our summary lists: Python 3.

Does Validate Config access the network?

SKILL.md contains no URLs. Its commands use uv, which can reach the network depending on how they are called. This is read from the text; nothing was executed.

Is Validate Config safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Validate Config use?

Validate Config is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Validate Config use?

About 1.1k tokens (SKILL.md is roughly 4.4k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Validate Config?

Skills that share tags, products or a category with Validate Config: Foundry Deploy Fixtures (aviggiano/security, 144 stars), function Object() { [native code] } Patterns (ccashwell/evm-cortex, 131 stars), Test Fixtures (ccashwell/evm-cortex, 131 stars) and Foundry Differential Tests (aviggiano/security, 144 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Validate Config?

lidofinance (a GitHub organization) maintains it in lidofinance/diffyscan, which has 142 GitHub stars. The repository holds 5 skills in this directory. The repository was last updated on October 6, 2026.

Source: lidofinance/diffyscan on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Validate Config

Install Validate Config

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

1. Load and inspect

2. Review overrides and exceptions

3. Report

Files

Compare with similar skills

Similar skills

Foundry Deploy Fixtures

function Object() { [native code] } Patterns

Test Fixtures

Foundry Differential Tests

Cross Chain Security

Library Patterns

More from lidofinance/diffyscan

Add Explorer

Allowed Diffs

New Config

Debug Diff

Questions about Validate Config

Install Validate Config

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

1. Load and inspect

2. Review overrides and exceptions

3. Report

Files

Compare with similar skills

Similar skills

More from lidofinance/diffyscan

Related

Questions about Validate Config