Evo is an agent plugin that turns a codebase into an automated experiment loop, discovering metrics, changing code, and testing whether those changes improve the results. It is used to optimize software through parallel subagents, tree-based exploration, shared experiment records, and optional regression or safety gates. The catalogue entries provide agent skills, hooks, commands, and other workflow components for operating Evo.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
git clone --depth 1 https://github.com/evo-hq/evoWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/hooks/evo-hq/evo/session-start)<a href="https://agentmods.dev/hooks/evo-hq/evo/session-start"><img src="https://agentmods.dev/badge/hooks/evo-hq/evo/session-start/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/hooks/evo-hq/evo/session-start"><img src="https://agentmods.dev/badge/hooks/evo-hq/evo/session-start.svg" alt="Reviewed on agentmods" width="80" height="20"></a>Grade C, and why
SessionStart scanned grade C with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the commands this hook runs, not an audit. A hook is shell that executes on your machine at the event it names, which is why every command in it is printed with what was found.
Encoded or obfuscated payloadhighSupply chain
base64 or hex that is decoded and executed hides what actually runs from anyone reading the file.
"command": "node -e \"eval(Buffer.from('Y29uc3QgZnM9cmVxdWlyZSgnZnMnKSxvcz1yZXF1aXJlKCdvcycpLHBhdGg9cmVxdWlyZSgncGF0aCcpLGNwPXJlcXVpcmUoJ2NoaWxkX3Byb2Nlc3MnKSx0dHk9cmVxdWlyZSgndHR5Jyk7bGV0IGlucHV0PUJ1ZmZlci5hbGxvYygwKTt0 This is a copy
83% identical to PreToolUse — 3 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
{
"SessionStart": [
{
"hooks": [
{
"type": "command",
"command": "node -e \"eval(Buffer.from('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','base64').toString())\""
}
]
}
]
}What else hooks.json configures
This page is one entry in a file that holds 6. Installing the file brings all of them; each is measured and scanned on its own page.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 12 lines scan C fd6aadbfa267
SessionStart is a hook published in the GitHub repository evo-hq/evo (1,487 stars, last pushed 23d ago), licensed Apache-2.0. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it C with 1 finding (encoded or obfuscated payload). It is 83% identical to PreToolUse, differing in 3 lines, and is treated as a copy.
Other hooks, from other repositories
PreToolUse
Runs before the agent uses a tool, executing pretooluse.sh via sh. From JotJunior/cstk.
SessionStart
Runs when a session starts on startup, executing install_pkgs.sh. From supabase/supabase.
PostToolUse
Runs after a tool call finishes for Write and Edit tool calls, executing format_and_lint.sh. From supabase/supabase.
SessionStart
Runs when a session starts, executing on-start.js via node. From google-gemini/gemini-cli.
PreToolUse
Runs before the agent uses a tool for Bash tool calls, running an inline shell check. From apache/superset.
PreToolUse
Runs before the agent uses a tool, executing pre-write.sh and pre-bash.sh (2 commands). From anthropics/claude-cookbooks.