sentinel

sentinel is a command for coding agents from get-convex/convex-agent-plugins. It costs 13 tokens per session (304 once invoked), scanned A, original, MIT.

A command for capturing production errors in a Convex deployment, a hosted backend application. It stores redacted errors in the user’s own deployment.

In plain words
What is it for?
Use it to collect and review errors, crashes, concurrency signals, and breadcrumbs, and optionally classify recurring errors and open fix pull requests.
Why use it?
It gives developers a way to inspect server and client failures without storing raw secrets or sending the captured data to a third party.

Command

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 commands/get-convex/convex-agent-plugins/sentinel
Clone the repo
git clone --depth 1 https://github.com/get-convex/convex-agent-plugins

Wrote 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.

agentmods badge for sentinel

README.md
[![agentmods](https://agentmods.dev/badge/commands/get-convex/convex-agent-plugins/sentinel.svg)](https://agentmods.dev/commands/get-convex/convex-agent-plugins/sentinel)
Your own site
<a href="https://agentmods.dev/commands/get-convex/convex-agent-plugins/sentinel"><img src="https://agentmods.dev/badge/commands/get-convex/convex-agent-plugins/sentinel.svg" alt="Measured on agentmods" height="20"></a>
Per session 13 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 304 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found 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 $0.00304
Opus 5 $0.00006 $0.00152
Sonnet 5 $0.00003 $0.00061
Haiku 4.5 $0.00001 $0.00030

Measured 4d ago against content hash a430c446f76b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

sentinel 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 4d ago.

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.

commands/sentinel.md · 21 lines

What it actually says

Capture production errors in your own deployment

Install @convex-dev/sentinel to capture production errors (server function failures, client JS/React crashes, OCC and scale signals) into a table in the user's OWN deployment, redacted at write time, then react to new ones. Data never leaves the user's deployment.

Steps

  1. Install the component: app.use(sentinel) in convex/convex.config.ts.
  2. Wire the client SDK: a React error boundary plus window.onerror/unhandledrejection and breadcrumbs.
  3. Redaction runs at write time and is on by default (default-deny on secret key names and value patterns).
  4. Read recent errors with the Convex CLI (convex data, run-once-query); react to new ones via the monitor's prod_error event.
  5. Optionally enable the self-healing cron: triage classifies each error and, for recurring non-transient ones, hands it to ai-runner to open a fix PR.

Rules

  • Redaction is mandatory and on by default — never store raw secrets; the agent's reads reach the model provider.
  • Data stays in the user's deployment; never send it to a third party.
  • Sample and cap to control volume and cost.
  • Capturing PROD errors needs a deployed cloud app; install works anonymously.
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. 4d ago First seen · 21 lines · 13 tokens per session scan A a430c446f76b

Subscribe to this mod's changes

sentinel is a command published in the GitHub repository get-convex/convex-agent-plugins (112 stars, last pushed 6d ago), licensed MIT. It adds 13 tokens to every session and 304 once invoked, about $0.0001 per session on Opus 5. 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.