Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add V-Songbird/slag/plugin install verityWrote 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/v-songbird/slag/ground-truth)<a href="https://agentmods.dev/skills/v-songbird/slag/ground-truth"><img src="https://agentmods.dev/badge/skills/v-songbird/slag/ground-truth/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/v-songbird/slag/ground-truth"><img src="https://agentmods.dev/badge/skills/v-songbird/slag/ground-truth.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 | $0.00151 | $0.00710 |
| Opus 5 | $0.00076 | $0.00355 |
| Sonnet 5 | $0.00030 | $0.00142 |
| Haiku 4.5 | $0.00015 | $0.00071 |
Grade A, and why
ground-truth 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 9d 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 — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Verity — ground-truth
Fetch and return the authoritative source for a Claude Code question. Two fetch paths depending on what is being asked.
Path A — Official Claude Code docs (live fetch)
Use for any question about Claude Code features, behavior, settings, permissions, hooks, CLI, plugins, agents, skills, MCP, or the Agent SDK.
Step 1 — discover the right page:
WebFetch https://code.claude.com/llms.txt
This returns a Markdown index of all doc pages with titles and one-line descriptions. Scan it to find the slug(s) that match the question. Each entry is formatted as:
- [Page Title](https://code.claude.com/docs/en/{slug}.md): Brief description
Step 2 — fetch the page as raw Markdown:
WebFetch https://code.claude.com/docs/en/{slug}.md
Returns raw Markdown source — not rendered HTML. Quote the relevant section(s) in your response. Only fetch additional pages if the first does not fully answer the question.
Fallback: If no slug in llms.txt clearly matches the question, fetch https://code.claude.com/docs/en/overview.md to orient, then try the closest slug from the index.
Path B — Undocumented host/session MCP tools (bundled reference)
Use for questions about spawn_task, dismiss_task, mark_chapter, read_widget_context, show_widget, visualize, ccd_session, ccd_session_mgmt, scheduled-tasks, ccd_directory, or any other session-injected host tool.
Read ${CLAUDE_PLUGIN_ROOT}/references/host-mcp-tools.md
This file is canonical truth. Do not attempt live introspection of the session toolset to answer these questions — the bundled reference is sourced from direct parameter-schema observation, version-labeled, and more reliable than runtime inference. If a tool the user asks about is not listed in the file, say so explicitly and cite the observation date from the file header so the user knows the reference may be incomplete for a newer harness version.
Source citation (required)
Always end your answer with a citation so the user knows what was fetched and when:
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.
- 9d ago First seen · 63 lines · 151 tokens per session scan A cfcef6b91f11
ground-truth is a skill published in the GitHub repository V-Songbird/slag (1 stars, last pushed 4d ago), licensed MIT. It adds 151 tokens to every session and 710 once invoked, about $0.0008 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 2026-08-31.
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