arc-corpus

arc-corpus is a skill for Claude Code from cwensel/arcaneum. It costs 67 tokens per session (2,029 once invoked), scanned A, original, MIT.

A tool for managing one searchable content collection in both semantic search and full-text search systems. Semantic search finds related meaning, while full-text search matches words and phrases.

In plain words
What is it for?
Use it to create, sync, inspect, verify, export, import, or delete collections of PDFs, code, or Markdown files.
Why use it?
It keeps the two search indexes synchronized instead of requiring separate updates and risking inconsistent results.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the arc plugin — 5 skills, 10 commands shipped together

Good fit Use it to create, sync, inspect, verify, export, import, or delete collections of PDFs, code, or Markdown files.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/cwensel/arcaneum/arc-corpus
Install

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.

Any agent
npx skills add cwensel/arcaneum --skill arc-corpus
Clone the repo
git clone --depth 1 https://github.com/cwensel/arcaneum

Made for: Claude Code.

Or install arc, the plugin that ships this one along with the rest of its 5 skills, 10 commands.

Wrote 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.

agentmods badge for arc-corpus

README.md
[![agentmods](https://agentmods.dev/badge/skills/cwensel/arcaneum/arc-corpus/github.svg)](https://agentmods.dev/skills/cwensel/arcaneum/arc-corpus)
Your own site
<a href="https://agentmods.dev/skills/cwensel/arcaneum/arc-corpus"><img src="https://agentmods.dev/badge/skills/cwensel/arcaneum/arc-corpus/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.

agentmods 80×15 button for arc-corpus

Your own site · 80×15
<a href="https://agentmods.dev/skills/cwensel/arcaneum/arc-corpus"><img src="https://agentmods.dev/badge/skills/cwensel/arcaneum/arc-corpus.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,029 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 3 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 Rogue Agent · line 16
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
  • medium Excessive Agency · line 24
    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 73
    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.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00067 $0.02029
Opus 5 $0.00034 $0.01014
Sonnet 5 $0.00013 $0.00406
Haiku 4.5 $0.00007 $0.00203

Measured 8d ago against content hash f4046ab739d3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

arc-corpus 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 8d 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.

.claude-plugin/skills/arc-corpus/SKILL.md · 183 lines

How it starts

The opening of the file, as written. The whole thing — 183 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Corpus Management (Dual-Index)

A corpus maintains both a Qdrant collection (semantic search) and a MeiliSearch index (full-text search) in sync.

For adding or updating content, always prefer arc corpus sync over arc index, arc collection, or arc indexes. The corpus commands manage Qdrant and MeiliSearch together. Single-system commands (arc index, arc collection, arc indexes) are for advanced workflows that need one system without the other.

# Create corpus (creates both collection and index)
arc corpus create MyCorpus --type pdf
arc corpus create MyCorpus --type code
arc corpus create MyCorpus --type markdown
arc corpus create MyCorpus --type pdf --models qwen3-embed,jina-v3  # Multiple models

# Delete corpus (deletes both collection and index)
arc corpus delete MyCorpus              # With confirmation prompt
arc corpus delete MyCorpus --confirm    # Skip confirmation
arc corpus delete MyCorpus --confirm --json  # JSON output

# Sync files to both systems (preferred command for adding/updating content)
arc corpus sync MyCorpus /path/to/files
arc corpus sync MyCorpus /path/one /path/two /path/three    # Multiple directories
arc corpus sync MyCorpus /path/to/files --parity            # Detect renames, remove files no longer on disk
arc corpus sync MyCorpus /path/to/files --parity --dry-run  # Preview parity changes first
arc corpus sync MyCorpus /path/to/files --force             # Force reindex
arc corpus sync MyCorpus /path/to/files --verify            # Verify after sync
arc corpus sync MyCorpus /path/to/files --verbose           # Show progress
arc corpus sync MyCorpus /path/to/files --no-gpu            # CPU-only mode (stable on Apple Silicon)

# Keep a git repo in sync automatically (installs a git hook)
arc corpus hook install                               # Guided: pick/create corpus, choose hooks
arc corpus hook install MyCorpus                      # Auto-sync on every commit
arc corpus hook install MyCorpus --hook post-merge    # Also stay current after pulls
arc corpus hook install MyCorpus --service            # Plus an OS watcher for reboot recovery
arc corpus hook status                                # What is installed in this repo
arc corpus hook uninstall MyCorpus                    # Remove just this corpus's hook

# Sync only what a commit touched, without installing a hook
arc corpus sync MyCorpus --changed-since HEAD              # Last commit
arc corpus sync MyCorpus --changed-since ORIG_HEAD..HEAD   # Since a pull

# Repair incomplete or garbled files
arc corpus repair MyCorpus                            # Detect and fix quality issues
arc corpus repair MyCorpus --dry-run                  # Preview what would be repaired
arc corpus repair MyCorpus --quality-threshold 0.5    # More aggressive detection
arc corpus repair MyCorpus --verbose                  # Show per-file quality scores

# View corpus info (both systems)
arc corpus info MyCorpus
arc corpus info MyCorpus --json

# List indexed items with parity status
arc corpus items MyCorpus               # Table output with Q/M chunk counts
arc corpus items MyCorpus --json        # JSON output for automation

# Check and restore parity between systems
arc corpus parity MyCorpus              # Check and backfill single corpus
arc corpus parity MyCorpus --dry-run    # Preview only
arc corpus parity MyCorpus --verify     # Verify chunk counts match
arc corpus parity MyCorpus --repair-metadata  # Fix missing git metadata (code corpora)
arc corpus parity MyCorpus --verbose    # Detailed progress

# All-corpora mode (no corpus name)
arc corpus parity                       # Process all corpora
arc corpus parity --dry-run             # Preview all
arc corpus parity --confirm             # Skip confirmation prompt

# Create missing MeiliSearch indexes for qdrant_only corpora
arc corpus parity --create-missing --dry-run   # Preview what would be created
arc corpus parity --create-missing --confirm   # Create and sync all

Read the full file on GitHub · 183 lines

Changes

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.

  1. 8d ago First seen · 183 lines · 67 tokens per session scan A f4046ab739d3

Subscribe to this mod's changes

arc-corpus is a skill published in the GitHub repository cwensel/arcaneum (7 stars, last pushed 4d ago), licensed MIT. It adds 67 tokens to every session and 2,029 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 2026-08-31.

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