Vellum Assistant is a personal AI assistant that remembers information about users, learns their preferences, and takes actions across connected apps. It is intended for people who want an assistant that can manage conversations, unfinished work, and proactive notifications over time. The catalogue skills, hooks, instruction, and setting configure or extend how the assistant works.
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.
npx skills add vellum-ai/vellum-assistant --skill slackgit clone --depth 1 https://github.com/vellum-ai/vellum-assistantWrote 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/skills/vellum-ai/vellum-assistant/slack)<a href="https://agentmods.dev/skills/vellum-ai/vellum-assistant/slack"><img src="https://agentmods.dev/badge/skills/vellum-ai/vellum-assistant/slack/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/skills/vellum-ai/vellum-assistant/slack"><img src="https://agentmods.dev/badge/skills/vellum-ai/vellum-assistant/slack.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 64 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
- medium Data Exfiltration · line 165 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00015 | $0.03304 |
| Opus 5 | $0.00008 | $0.01652 |
| Sonnet 5 | $0.00003 | $0.00661 |
| Haiku 4.5 | $0.00002 | $0.00330 |
Grade A, and why
slack scanned grade A 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 2d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
This is the only way to call Slack. Never fetch a Slack token yourself (`assistant credentials reveal`, an environment variable, a pasted value) and never call `slack.com/api` with `curl` or any other HTTP client: a toke How it starts
The opening of the file, as written. The whole thing — 243 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You help users interact with their Slack workspace. All Slack operations use the Slack Web API directly via assistant oauth request -- there are no dedicated Slack tools. Use relative Slack API method paths such as /chat.postMessage; the provider supplies the Slack host.
Which provider to pass
Two Slack credentials can exist. They act as different identities and reach different things, so the right one depends on the operation, not only on which is configured.
| Provider | Sends | Acts as | Reaches |
|---|---|---|---|
slack_channel |
the bot token | the assistant | channels the bot has joined |
slack |
the installer's user token | that person | channels that person is in, and search.messages |
Posting: slack_channel. A message sent through slack arrives from the person who connected it, not from the assistant. Where that is the only credential present, say so before posting rather than posting as them silently.
search.messages: slack only. It is a user-token method. --provider slack_channel sends the bot token even on an install that stored a user token, so it cannot serve search at all.
Everything else: whichever is present, preferring slack_channel when both are. Reach differs rather than one being better: the bot sees channels it was invited to, the user token sees channels that person belongs to.
A workspace has only slack when Slack was connected as an integration without running the setup wizard, which means no bot. oauth status <provider> reports whether a given one holds a connection. Passing a provider that holds none fails with a not-configured error rather than falling back on its own.
Resolution Scripts
Use these scripts to resolve Slack channel and user names to IDs. Results are cached locally so repeated lookups are free (no API calls).
What ships with it
5 files 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.
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.
- 2d ago Changed · +2 lines 1a75fffab6f3
- 8d ago Changed · +36 lines 3b7b944ae342
- 9d ago First seen · 205 lines · 15 tokens per session scan A ba42920b799a
slack is a skill published in the GitHub repository vellum-ai/vellum-assistant (1,234 stars, last pushed today), licensed MIT. It adds 15 tokens to every session and 3,304 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
lictor-security-check
Pre-release security audit for ANY project — AI-built or hand-written, web or mobile. Scans the codebase for the full range of real-world risks that get apps breached: leaked API & AI-provider keys, exposed configs/secrets, broken auth & access control (IDOR), injection (SQL/XSS/command), SSRF, open databases & cloud…
lictor-rotate
Walks the user through rotating a leaked API key — step by step, provider-specific. Knows the exact URL to visit, the exact button to click, and how to verify the rotation worked. Supports Stripe, OpenAI, Anthropic, Google Cloud / AI Studio, GitHub, AWS, Slack, Supabase, Firebase, Postmark, and generic OAuth providers.
lictor-explain
Takes any security finding, error message, or jargon-heavy security advice and explains it in plain English. Use this when someone is confused by what /lictor-security-check found, or when they got a security warning from another tool and don't understand it.
lictor-fix-it
Applies the fixes recommended by /lictor-security-check, with the user's explicit permission for each change. Walks through findings one at a time, shows the proposed change, gets approval, applies, runs tests if available, and moves on. Some fixes (rotating leaked credentials) require the user to act outside Claude …
continual-learning
Nightly refinement of an existing per-repo review-style prompt using this reviewer's own finding outcomes. Read confirmed (resolved-by-commit / thumbs-up) and dismissed (thumbs-down) findings, promote the bug patterns the team actually fixes, demote the false-positive patterns, reconcile against the current prompt…
ha-logs
A read-only troubleshooting skill for querying Hope Agent’s local SQLite databases, which store logs, conversations, and background-job status.