agentmods.dev

SubagentStart

A hook that runs when a subagent starts and invokes a Catenary command.

In plain words
What is it for?
Running Catenary's start-of-subagent check or setup action whenever a subagent begins.
Why use it?
It keeps the configured subagent-start action automatic, so it does not depend on someone remembering to run it.

Hook

8 26d ago A scan tokens not measured AGPL-3.0
View the source file TwoWells/Catenary
Install

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.

agentmods
npx agentmods add hooks/twowells/catenary/subagent-start
Clone the repo
git clone --depth 1 https://github.com/TwoWells/Catenary
Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin unknown No closer match found in the catalogue.
Security

Grade A, and why

SubagentStart 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 2d 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.

plugins/catenary/hooks/hooks.json · 13 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Changes

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.

  1. 2d ago First seen · 13 lines scan A e1fb7ef84af0

Subscribe to this mod's changes

SubagentStart is a hook published in the GitHub repository TwoWells/Catenary (8 stars, last pushed 26d ago), licensed AGPL-3.0. 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 2026-08-31.

Building agentsData and AIai-agentsantigravity-cli-extensionsclaude-code-extensioncoding-agentsdeveloper-toolslanguage-server-protocol
Related

Other hooks, from other repositories

SubagentStart

Runs when a subagent starts, running node. From paceaitian/paceflow.

paceaitian/paceflow · not measured

SubagentStop

Runs when a subagent finishes, running node. From paceaitian/paceflow.

paceaitian/paceflow · not measured

SubagentStop

Runs when a subagent finishes, executing planks-check.sh and background-custody.sh (2 commands). From dmytri/shipshape.

dmytri/shipshape · not measured

SubagentStop

Runs when a subagent finishes, executing _run_hook.sh via bash. From lemoncrow-lab/lemoncrow.

lemoncrow-lab/lemoncrow · not measured

SubagentStop

Runs when a subagent finishes, running bash "$CLAUDE_PROJECT_DIR"/.claude/hooks/subagent-stop. From Edmonds-Commerce-Limited/claude-code-hooks-daemon.

Edmonds-Commerce-Limited/claude-code-hooks-daemon · not measured

SubagentStart

Runs when a subagent starts, running bash "$CLAUDE_PROJECT_DIR"/.claude/hooks/subagent-start. From Edmonds-Commerce-Limited/claude-code-hooks-daemon.

Edmonds-Commerce-Limited/claude-code-hooks-daemon · not measured