Plano is a proxy server and data plane that handles shared infrastructure for applications built with AI agents, including agent routing, orchestration, model selection, traces, metrics, and guardrails. Developers use it to connect agents and language models to production applications without embedding this middleware in each application. The catalogue entries provide skills and instructions for operating or developing with Plano.
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 katanemo/plano --skill plano-filter-guardrailsgit clone --depth 1 https://github.com/katanemo/planoWrote 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/katanemo/plano/plano-filter-guardrails)<a href="https://agentmods.dev/skills/katanemo/plano/plano-filter-guardrails"><img src="https://agentmods.dev/badge/skills/katanemo/plano/plano-filter-guardrails/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/katanemo/plano/plano-filter-guardrails"><img src="https://agentmods.dev/badge/skills/katanemo/plano/plano-filter-guardrails.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00031 | $0.00210 |
| Opus 5 | $0.00015 | $0.00105 |
| Sonnet 5 | $0.00006 | $0.00042 |
| Haiku 4.5 | $0.00003 | $0.00021 |
Grade A, and why
plano-filter-guardrails 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 10d 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.
What it actually says
Plano Filter Chains and Guardrails
Use this skill when safety controls or filter pipelines need correction.
When To Use
- "Fix filter chain ordering"
- "Set up MCP filters correctly"
- "Improve guardrail rejection behavior"
- "Harden request processing for safety"
Apply These Rules
filter-mcpfilter-guardrailsfilter-ordering
Execution Checklist
- Configure filter
type,transport, andtoolexplicitly for MCP. - Ensure rejection messages are clear and actionable.
- Order chain as guards -> rewriters -> enrichment -> output checks.
- Prevent expensive enrichment on unsafe requests.
- Verify with representative blocked and allowed test prompts.
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.
- 10d ago First seen · 34 lines · 31 tokens per session scan A 58d9a71f435d
plano-filter-guardrails is a skill published in the GitHub repository katanemo/plano (7,047 stars, last pushed 21d ago), licensed Apache-2.0. It adds 31 tokens to every session and 210 once invoked, about $0.0002 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.
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