Caliber is a tool that generates and continuously updates AI context and configuration files for software repositories, including CLAUDE.md, AGENTS.md, and platform-specific rules. Development teams use it to keep coding agents aligned with the current codebase across tools such as Claude Code, Cursor, Codex, OpenCode, and GitHub Copilot. Its catalogue entries include skills, hooks, rules, instructions, and settings for configuring that workflow.
Borrowing it
Nothing to install: this file belongs to caliber-ai-org/ai-setup. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/caliber-ai-org/ai-setup/master/.claude/settings.jsongit clone --depth 1 https://github.com/caliber-ai-org/ai-setupWrote 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/caliber-ai-org/ai-setup/post-tool-use-failure)<a href="https://agentmods.dev/hooks/caliber-ai-org/ai-setup/post-tool-use-failure"><img src="https://agentmods.dev/badge/hooks/caliber-ai-org/ai-setup/post-tool-use-failure.svg" alt="Measured on agentmods" height="20"></a>Grade A, and why
PostToolUseFailure scanned grade A with 0 findings 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 6d 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
{
"PostToolUseFailure": [
{
"matcher": "",
"hooks": [
{
"type": "command",
"command": "caliber learn observe --failure",
"description": "Caliber: recording tool failure for session learning"
}
]
}
]
}What else settings.json configures
This page is one entry in a file that holds 8. 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.
- 6d ago First seen · 14 lines scan A 97fc3fb99f74
PostToolUseFailure is a hook published in the GitHub repository caliber-ai-org/ai-setup (1,262 stars, last pushed 1mo ago), licensed MIT. Its token cost is not measured: a hook is shell that never enters the context. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other hooks, from other repositories
SessionStart
Runs when a session starts on startup, running echo '✓ plugin-development loaded: Use /plugin-development:i. From ivan-magda/claude-code-plugin-template.
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.
PreCompact
Runs before the context is compacted for manual and auto tool calls, executing hook-handler.cjs via node (4 commands). From ruvnet/RuView.
SessionStart
Runs when a session starts on startup, clear and compact, executing run-hook.cmd. From obra/superpowers.