webhook-post

A tool that sends an HTTP POST request to a configured webhook address. A webhook is a web URL that receives data or triggers an action.

In plain words
What is it for?
Use it to send data or event notifications to a webhook endpoint.
Why use it?
It lets an agent notify or pass data to another configured service through a web request.

Skill for Claude CodeCodex

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 skills/keyargo/custodian-kernel/webhook-post
Any agent
npx skills add KeyArgo/custodian-kernel --skill webhook-post
Clone the repo
git clone --depth 1 https://github.com/KeyArgo/custodian-kernel

Made for: Claude Code, Codex.

Per session 13 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 307 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 92% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00013 $0.00307
Opus 5 $0.00006 $0.00153
Sonnet 5 $0.00003 $0.00061
Haiku 4.5 $0.00001 $0.00031

Measured 2d ago against content hash e21aeaf1d737, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

webhook-post 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/execute.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

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.

Origin

This is a copy

92% identical to slack-channel-list — 22 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.

custodian/bundled_skills/communication/webhook-post/SKILL.md · 51 lines

What it actually says

Webhook Post

Send an HTTP POST to any configured webhook endpoint

Authority band

This tool runs under L1 authority in the Custodian kernel. Trivial autonomous spend or free side-effect — no human approval required.

Inputs

Parameter Type Required Description
(see execute.py for full schema)

Configuration

No additional configuration required — uses credentials already wired to Custodian.

Usage

custodian tools run webhook-post --param value

Custodian governance

Every call to this tool passes through the Custodian kernel authority check before executing. The kernel verifies the current authority band, checks spending caps where applicable, logs the action to the OCSF audit trail, and escalates to a human operator if the action exceeds the declared band.

Adding this tool to any Hermes agent session requires no code changes — declare custodian-band: L1 in the SKILL.md frontmatter and the kernel wraps it automatically.

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 51 lines · 13 tokens per session scan A e21aeaf1d737

Subscribe to this mod's changes

webhook-post is a skill published in the GitHub repository KeyArgo/custodian-kernel (118 stars, last pushed 10d ago), licensed MIT. It adds 13 tokens to every session and 307 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to slack-channel-list, differing in 22 lines, and is treated as a copy.