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 magnus919/agent-skills --skill tailnet-policygit clone --depth 1 https://github.com/magnus919/agent-skillsWrote 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/magnus919/agent-skills/tailnet-policy)<a href="https://agentmods.dev/skills/magnus919/agent-skills/tailnet-policy"><img src="https://agentmods.dev/badge/skills/magnus919/agent-skills/tailnet-policy/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/magnus919/agent-skills/tailnet-policy"><img src="https://agentmods.dev/badge/skills/magnus919/agent-skills/tailnet-policy.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 5 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 Excessive Agency · line 21 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
- medium Excessive Agency · line 182 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
- medium Excessive Agency · line 186 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
- medium Excessive Agency · line 196 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
- medium Excessive Agency · line 287 Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 | $0.00060 | $0.02282 |
| Opus 5.5 | $0.00024 | $0.00913 |
| Sonnet 5.5 | $0.00012 | $0.00456 |
| Haiku 4.5 | $0.00006 | $0.00228 |
Grade A, and why
tailnet-policy 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 12d 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.
How it starts
The opening of the file, as written. The whole thing — 307 lines — stays where its author put it; the contents beside it link to each section on GitHub.
tailnet-policy
Security preflight
Before enabling SSH, Serve, connector access or changing access policy, read the bundle's security triage. Also load it for Tailworm or suspected compromise. Preserve tested recovery access before disabling embedded SSH; check mode is not a forwarding fix. Treat reported findings as version-specific until current advisories establish applicability.
Confirm the target, scope, and rollback path before acting. Read-only discovery may proceed without confirmation.
Overview
Headscale uses Tailscale-compatible policy files written in huJSON (Human JSON — standard JSON with trailing commas and // comments). Policy files control:
- ACLs (deprecated legacy syntax) —
{action, users, ports}rules - Grants (modern syntax) —
{src, dst, ip, proto, via}rules - Tags — Node identity tags (
tag:dev,tag:prod) - TagOwners — Which users/groups can apply which tags
- AutoApprovers — Auto-approval for subnet routers and exit nodes
- Tailscale SSH — SSH access rules via
ssh.usersandssh.action
ACLs vs Grants
| Feature | ACLs (legacy) | Grants (modern) |
|---|---|---|
| Format | {action: "accept", users: [...], ports: [...]} |
{src: [...], dst: [...], ip: [...], proto: "tcp"} |
| Port filtering | Embedded in ports: ["*:*"] |
Separate ip field for ports |
| Protocol filtering | Not supported | proto field (tcp, udp, icmp) |
| Destination routing | Not supported | via field for relay/exit nodes |
| Status | Deprecated by Tailscale | Current recommended syntax |
Use Grants wherever possible. The migrate-acls-to-grants.py script can convert legacy ACL files automatically.
Policy Location
The policy file path is configured in Headscale's config.yaml:
policy:
path: /etc/headscale/policy.hujson
After modifying the policy file, reload it on the Headscale server:
# Reload via SIGHUP
kill -HUP $(pgrep headscale)
# Or use the convenience script
./skills/tailnet-policy/reload-headscale-policy.sh
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.
- 12d ago Changed · +10 lines 007bee6a34b0
- 2mo ago First seen · 297 lines · 60 tokens per session scan A e10e7af1440d
tailnet-policy is a skill published in the GitHub repository magnus919/agent-skills (166 stars, last pushed 2d ago), licensed MIT. It adds 60 tokens to every session and 2,282 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-09-03.
tailnet-policy compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| tailnet-policymagnus919/agent-skills | Skill | 166 | 2d ago | MIT | A | 60 | Claude Code |
| cocoreviewSnowflake-Labs/cocoplus | Skill | 727 | today | MIT | A | 57 | Claude Code |
| discussSnowflake-Labs/cocoplus | Skill | 727 | today | MIT | A | 54 | Claude Code |
| cocoharvestSnowflake-Labs/cocoplus | Skill | 727 | today | MIT | A | 68 | Claude Code |
| cocoscoutSnowflake-Labs/cocoplus | Skill | 727 | today | MIT | A | 59 | Claude Code |
| bloomSnowflake-Labs/cocoplus | Skill | 727 | today | MIT | A | 47 | Claude Code |
| klatchSnowflake-Labs/cocoplus | Skill | 727 | today | MIT | A | 54 | Claude Code |