Agent skill

Fork Test

by OriginProtocol in OriginProtocol/origin-dollar

Generate Foundry fork tests for contracts that need real on-chain integration coverage.

MITAuto-check passedTesting & QA

Install Fork Test

skills CLI

$ npx skills add OriginProtocol/origin-dollar --skill fork-test -a claude-code

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

GitHub CLI

$ gh skill install OriginProtocol/origin-dollar fork-test --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/OriginProtocol/origin-dollar.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.codex/skills/fork-test .claude/skills/fork-test && 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 "fork-test" agent skill from https://github.com/OriginProtocol/origin-dollar/tree/master/.codex/skills/fork-test into .claude/skills/fork-test/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fork-test", 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/OriginProtocol/origin-dollar/tree/master/.codex/skills/fork-test

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 OriginProtocol/origin-dollar --skill fork-test -a codex

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

GitHub CLI

$ gh skill install OriginProtocol/origin-dollar fork-test --agent codex

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

Manual copy

$ git clone --depth 1 https://github.com/OriginProtocol/origin-dollar.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.codex/skills/fork-test .agents/skills/fork-test && 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 "fork-test" agent skill from https://github.com/OriginProtocol/origin-dollar/tree/master/.codex/skills/fork-test into .agents/skills/fork-test/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fork-test", 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 OriginProtocol/origin-dollar --skill fork-test -a cursor

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

GitHub CLI

$ gh skill install OriginProtocol/origin-dollar fork-test --agent cursor

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

Manual copy

$ git clone --depth 1 https://github.com/OriginProtocol/origin-dollar.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.codex/skills/fork-test .cursor/skills/fork-test && 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 "fork-test" agent skill from https://github.com/OriginProtocol/origin-dollar/tree/master/.codex/skills/fork-test into .cursor/skills/fork-test/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fork-test", 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/OriginProtocol/origin-dollar.git --path .codex/skills/fork-test

--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 OriginProtocol/origin-dollar --skill fork-test -a gemini-cli

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

GitHub CLI

$ gh skill install OriginProtocol/origin-dollar fork-test --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/OriginProtocol/origin-dollar.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.codex/skills/fork-test .gemini/skills/fork-test && 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 "fork-test" agent skill from https://github.com/OriginProtocol/origin-dollar/tree/master/.codex/skills/fork-test into .gemini/skills/fork-test/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fork-test", 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 OriginProtocol/origin-dollar fork-test

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 OriginProtocol/origin-dollar --skill fork-test -a github-copilot

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

Manual copy

$ git clone --depth 1 https://github.com/OriginProtocol/origin-dollar.git skills-src && mkdir -p .github/skills && cp -r skills-src/.codex/skills/fork-test .github/skills/fork-test && 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 "fork-test" agent skill from https://github.com/OriginProtocol/origin-dollar/tree/master/.codex/skills/fork-test into .github/skills/fork-test/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fork-test", 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 OriginProtocol/origin-dollar --skill fork-test -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 OriginProtocol/origin-dollar fork-test --agent opencode

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

Manual copy

$ git clone --depth 1 https://github.com/OriginProtocol/origin-dollar.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.codex/skills/fork-test .opencode/skills/fork-test && 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 "fork-test" agent skill from https://github.com/OriginProtocol/origin-dollar/tree/master/.codex/skills/fork-test into .opencode/skills/fork-test/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "fork-test", 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: fork-test
GitHub stars: 153
Token cost: ~1.2k tokens
SKILL.md length: 455 words
Files: 1
Skills in repo: 7
Repo updated: Oct 6, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Generate Foundry fork tests for contracts that need real on-chain integration coverage.

Works in 6 steps: Directory layout → Inheritance chain → Shared setup contract → …
The user asks for fork tests
SKILL.md covers 1. Directory layout, 2. Inheritance chain, 3. Shared setup contract and 4. Concrete test naming, plus 3 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Fork Test is an agent skill from OriginProtocol/origin-dollar. Generate Foundry fork tests for contracts that need real on-chain integration coverage. Use when the user asks for fork tests, mainnet or chain fork coverage, or integration tests against live protocol state.

Its SKILL.md is about 1.2k 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 Testing & QA, covering Smart contracts and Integration testing. The repository describes itself as: OUSD and OETH are stablecoins that passively accrue yield while you are holding it. The licence is MIT.

When your agent uses it

The user asks for fork tests
Chain fork coverage
Integration tests against live protocol state

Example prompts

“/fork-test”

Workflow steps

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

Directory layout
Inheritance chain
Shared setup contract
Concrete test naming
What belongs in fork tests
Chain mapping

What it can do on your machine

Read from SKILL.md and the folder at commit ae82163. 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
No scripts in the folder and no shell commands in SKILL.md (its code samples are solidity).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
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

Fork Test loads about 1.2k tokens when it runs. Until then it costs about 55 tokens; SKILL.md has 455 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~55
When it runs · the whole SKILL.md, loaded when a task matches: ~1.2k

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 OriginProtocol/origin-dollar at commit ae82163, republished under its MIT licence (© OriginProtocol). 455 words, ~1,192 tokens.

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

name: fork-test
description: Generate Foundry fork tests for contracts that need real on-chain integration coverage. Use when the user asks for fork tests, mainnet or chain fork coverage, or integration tests against live protocol state.

Fork Test

Generate Foundry fork tests for contracts whose behavior depends on real on-chain state, live liquidity, routers, gauges, or oracle reads.

1. Directory layout

text

contracts/tests/fork/<category>/<ContractName>/
├── shared/
│   └── Shared.t.sol
└── concrete/
    ├── Deposit.t.sol
    ├── Withdraw.t.sol
    └── Rebalance.t.sol

Rules:

fork tests are concrete only; do not add a fuzz/ directory
create files only for functions with meaningful on-chain integration behavior
keep simple setters, access control checks, and pure validation in unit tests

2. Inheritance chain

text

forge-std/Test
  └─ Base
       └─ BaseFork
            └─ Fork_<Contract>_Shared_Test
                 └─ Fork_Concrete_<Contract>_<Feature>_Test

Base owns shared actors, constants, IERC20 external token refs, and fork IDs. All typed contract/proxy/mock state variables are declared in each Shared.t.sol using interface types. BaseFork owns chain fork helpers.

Interface-only testing

Same rules as unit tests — use interfaces, not concrete contracts:

Import interfaces: IVault, IOToken, IProxy, strategy interfaces from contracts/interfaces/strategies/
Deploy fresh contracts with vm.deployCode instead of new (except mocks), and always reference artifact paths through tests/utils/Artifacts.sol (e.g. vm.deployCode(Vaults.OETH, abi.encode(address(weth)))); add the entry to the relevant sub-library if it does not exist yet
Cast forked addresses to interfaces: oethVault = IVault(Mainnet.OETH_VAULT)
Reference events from interfaces: emit IVault.EventName(...)

Product-specific vault types

Product	Token	Vault	Chain	Artifacts reference
OUSD	`OUSD`	`OUSDVault`	Mainnet	`Vaults.OUSD`
OETH	`OETH`	`OETHVault`	Mainnet	`Vaults.OETH`
OSonic	`OSonic`	`OSVault`	Sonic	`Vaults.OS`
OETHBase	`OETHBase`	`OETHBaseVault`	Base	`Vaults.OETH_BASE`

Add the entry to tests/utils/Artifacts.sol if it does not exist yet.

Never use OETHVault for Sonic tests.

3. Shared setup contract

shared/Shared.t.sol should keep setup in this order:

solidity

function setUp() public virtual override {
    super.setUp();
    _createAndSelectFork<Chain>();
    _deployFreshContracts();
    _configureContracts();
    label();
}

Decision rule:

deploy fresh contracts that the strategy or vault under test owns or manages
use forked addresses for external infrastructure such as routers, tokens, factories, and oracles

Pull canonical addresses from tests/utils/Addresses.sol.

4. Concrete test naming

File and contract naming:

text

concrete/Deposit.t.sol
Fork_Concrete_<ContractName>_Deposit_Test

Function naming patterns:

test_<function>()
test_<function>_<behavior>()
test_<function>_RevertWhen_<condition>()
test_<function>_emits<EventName>()

Casing rules:

function, behavior, and condition stay camelCase
RevertWhen is the only PascalCase token in the test name

Show full SKILL.md (173 more words)Show less

5. What belongs in fork tests

Fork-test these categories:

AMO pool interactions
real router swaps
oracle reads
gauge reward flows
cross-chain and bridge flows
vault rebases with real balances
zapper flows
multi-step end-to-end operations

Do not fork-test:

simple setters
straightforward view functions
access control checks
constructor validation
pure math and helper logic
input-validation-only reverts

Litmus test:

If a mock can faithfully reproduce the behavior, keep it in unit tests.

6. Chain mapping

Use the repository's fork helpers and address libraries consistently:

Mainnet -> _createAndSelectForkMainnet()
Base -> _createAndSelectForkBase()
Sonic -> _createAndSelectForkSonic()
Arbitrum if relevant -> _createAndSelectForkArbitrum()

Output expectations

When implementing fork tests:

keep them narrowly focused on real integration value
prefer a few strong end-to-end tests over broad but redundant coverage
label both fresh and forked contracts for readable traces
use interface-only imports; no concrete contract imports except mocks
deploy fresh contracts with vm.deployCode, not new (mocks are fine with new), and reference all artifact paths through tests/utils/Artifacts.sol — no inline "contracts/...sol:Name" strings
mirror existing fork test structure in the nearest comparable test suite before introducing a new pattern

Files

Just SKILL.md in .codex/skills/fork-test of OriginProtocol/origin-dollar.

Open the folder on GitHubat commit ae82163

Compare with similar skills

Fork Test 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.

Fork Test compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Fork Test this skillOriginProtocol/origin-dollar	153	—	~1.2k	Automated safety check: Pass	MIT	yesterday
Web3 Testingwshobson/agents	40k	11 repos	~2k	Automated safety check: Pass	MIT	3 days ago
DevchainNethereum/Nethereum	2.3k	—	~1.7k	Automated safety check: Pass	MIT	2 days ago
Contract Testscalus3/scalus	105	—	~1.6k	Automated safety check: Pass	Apache-2.0	yesterday
Plugin Testingpolyipseity/obsidian-terminal	948	—	~828	Automated safety check: Pass	AGPL-3.0	4 days ago
Create Modulecartography-cncf/cartography	4.1k	—	~2.5k	Automated safety check: Pass	Apache-2.0	yesterday

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Questions about Fork Test

What does Fork Test do?

Generate Foundry fork tests for contracts that need real on-chain integration coverage. Fork Test is an agent skill from OriginProtocol/origin-dollar. Generate Foundry fork tests for contracts that need real on-chain integration coverage.

When should I use Fork Test?

Fork Test fits situations like: the user asks for fork tests; chain fork coverage; integration tests against live protocol state.

How do I install Fork Test in Claude Code?

Run `npx skills add OriginProtocol/origin-dollar --skill fork-test -a claude-code`. Or copy the skill folder (.codex/skills/fork-test in OriginProtocol/origin-dollar) into .claude/skills/fork-test in your project. Claude Code loads it when a task matches its description.

How do I install Fork Test in Codex?

Run `npx skills add OriginProtocol/origin-dollar --skill fork-test -a codex`. Or copy the skill folder (.codex/skills/fork-test in OriginProtocol/origin-dollar) into .agents/skills/fork-test in your project. Codex loads it when a task matches its description.

Can I use Fork Test 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 OriginProtocol/origin-dollar --skill fork-test -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/fork-test, .gemini/skills/fork-test, .github/skills/fork-test and .opencode/skills/fork-test in your project.

What does Fork Test need to run?

SKILL.md names no scripts, command-line tools or credentials: Fork Test is instructions for the agent only.

Does Fork Test access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Fork Test 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 Fork Test use?

Fork Test 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 Fork Test use?

About 1.2k tokens (SKILL.md is roughly 4.8k 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 Fork Test?

Skills that share tags, products or a category with Fork Test: Web3 Testing (wshobson/agents, 40k stars), Devchain (Nethereum/Nethereum, 2.3k stars), Contract Test (scalus3/scalus, 105 stars) and Plugin Testing (polyipseity/obsidian-terminal, 948 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Fork Test?

OriginProtocol (a GitHub organization) maintains it in OriginProtocol/origin-dollar, which has 153 GitHub stars. The repository holds 7 skills in this directory. The repository was last updated on October 6, 2026.

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

Install Fork Test

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Fork Test

1. Directory layout

2. Inheritance chain

Interface-only testing

Product-specific vault types

3. Shared setup contract

4. Concrete test naming

5. What belongs in fork tests

6. Chain mapping

Output expectations

Files

Compare with similar skills

Similar skills

More from OriginProtocol/origin-dollar

Related

Questions about Fork Test