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 oscal-compass-lab/compliance-trestle-skills --skill trestle-validationgit clone --depth 1 https://github.com/oscal-compass-lab/compliance-trestle-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/oscal-compass-lab/compliance-trestle-skills/trestle-validation)<a href="https://agentmods.dev/skills/oscal-compass-lab/compliance-trestle-skills/trestle-validation"><img src="https://agentmods.dev/badge/skills/oscal-compass-lab/compliance-trestle-skills/trestle-validation/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/oscal-compass-lab/compliance-trestle-skills/trestle-validation"><img src="https://agentmods.dev/badge/skills/oscal-compass-lab/compliance-trestle-skills/trestle-validation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00054 | $0.02908 |
| Opus 5 | $0.00027 | $0.01454 |
| Sonnet 5 | $0.00011 | $0.00582 |
| Haiku 4.5 | $0.00005 | $0.00291 |
Grade A, and why
trestle-validation 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 — 322 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Trestle Validation and Troubleshooting
Validation Commands
Validate All Models
trestle validate -a
This command validates every OSCAL model in the workspace. -a is short for --all.
This skill uses -a in all examples.
What a clean run looks like: On a new workspace with no models, trestle validate -a finds no models.
The command exits with code 0. Little or no output is normal. No output means pass. It is not a failure.
After you add models, a pass lists each validated model. There are no ERROR lines. The exit code is 0.
Validate by Type
trestle validate -t catalog -n my-catalog
trestle validate -t profile -n my-profile
trestle validate -t component-definition -n my-compdef
trestle validate -t system-security-plan -n my-ssp
trestle validate -t assessment-plan -n my-assessment
trestle validate -t assessment-results -n my-results
trestle validate -t plan-of-action-and-milestones -n my-poam
Validate Specific File
trestle validate -f catalogs/my-catalog/catalog.json
Common Validation Errors
Schema Validation Errors
| Error | Cause | Fix |
|---|---|---|
Additional properties not allowed |
Extra fields in JSON that are not in the OSCAL schema | Remove the unexpected field |
required property 'uuid' missing |
Required UUID field is missing | Add a valid UUID (python -c "import uuid; print(uuid.uuid4())") |
is not of type 'string' |
Wrong data type for a field | Check the OSCAL schema for the expected type |
does not match pattern |
Value does not match the expected regex | Check format rules. Examples: UUID, date-time |
Workspace Structure Errors
| Error | Cause | Fix |
|---|---|---|
Not in a trestle workspace |
No .trestle/ directory found |
Run trestle init or go to the workspace root |
Model not found |
Model directory or file does not exist | Check spelling. Make sure you imported the model |
Duplicate model names |
Two models share the same name | Rename one of the conflicting models |
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 First seen · 322 lines · 54 tokens per session scan A 111c29434296
trestle-validation is a skill published in the GitHub repository oscal-compass-lab/compliance-trestle-skills (16 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 54 tokens to every session and 2,908 once invoked, about $0.0003 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.
Other skills, from other repositories
nist-800-53
Use when the user asks about NIST SP 800-53 Rev. 5 from an engineering perspective — selecting baselines, tailoring controls, modeling control inheritance from cloud providers and shared services, emitting OSCAL artifacts, or implementing controls in IaC and code rather than running them as a documentation exercise.…
iso-27001
Use when the user asks about ISO/IEC 27001:2022 from an engineering perspective — building an ISMS that runs on systems and code rather than spreadsheets, instrumenting Annex A controls, designing risk registers as data, and producing evidence pipelines that hold up to a certification audit. Engineer-voice, not…
soc-2
Use when the user asks about SOC 2 from an engineering perspective — Trust Services Criteria (TSC) implementation, evidence-as-code, continuous monitoring patterns, instrumenting controls, or designing systems that produce audit-ready evidence by default. Engineer-voice, not auditor-voice.
control-mapping
Maps NIST controls to FedRAMP requirements and documents. Use when helping with control implementation, compliance mapping, security baseline alignment, or understanding control requirements.
frmr-analysis
Analyzes FedRAMP FRMR documents to extract control mappings, KSI entries, and version changes. Use when the user asks about FedRAMP requirements, control mappings, compliance data, or needs to understand FRMR document content.
fedramp
Expert guidance for FedRAMP certification and compliance under CR26 (FedRAMP Consolidated Rules for 2026). Use this skill whenever a user asks about FedRAMP authorization, ATO (Authority to Operate), cloud security for federal government, NIST SP 800-53 controls, CSP compliance, or any of the core FedRAMP document…