pdf-cascade

pdf-cascade is a skill for Claude Code from roomi-fields/paper-trail. It costs 266 tokens per session (2,037 once invoked), scanned A, original, MIT.

A tool for finding and validating PDF copies of academic papers listed in a bibliography.

In plain words
What is it for?
It helps fetch one paper or process a batch of references through sources such as Crossref, arXiv, OpenAlex, Unpaywall, HAL, CORE, and archive.org, with optional dry runs and OCR reactivation.
Why use it?
It reduces the chance of downloading the wrong paper and records where each file came from so the acquisition can be checked later.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions Claude Code.

Part of the paper-trail plugin — 6 skills, 22 commands, 6 agents, 3 hooks shipped together

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.

agentmods
npx agentmods add skills/roomi-fields/paper-trail/pdf-cascade
Any agent
npx skills add roomi-fields/paper-trail --skill pdf-cascade
Clone the repo
git clone --depth 1 https://github.com/roomi-fields/paper-trail

Made for: Claude Code.

Or install paper-trail, the plugin that ships this one along with the rest of its 6 skills, 22 commands, 6 agents, 3 hooks.

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 pdf-cascade

README.md
[![agentmods](https://agentmods.dev/badge/skills/roomi-fields/paper-trail/pdf-cascade.svg)](https://agentmods.dev/skills/roomi-fields/paper-trail/pdf-cascade)
Your own site
<a href="https://agentmods.dev/skills/roomi-fields/paper-trail/pdf-cascade"><img src="https://agentmods.dev/badge/skills/roomi-fields/paper-trail/pdf-cascade.svg" alt="Measured on agentmods" height="20"></a>
Per session 266 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,037 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00266 $0.02037
Opus 5 $0.00133 $0.01019
Sonnet 5 $0.00053 $0.00407
Haiku 4.5 $0.00027 $0.00204

Measured 6d ago against content hash 39fc7ef6bd33, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

pdf-cascade 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 6d 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.

skills/pdf-cascade/SKILL.md · 223 lines

How it starts

The opening of the file, as written. The whole thing — 223 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill : pdf-cascade

Purpose

Wraps the paper-trail worker B's acquisition cascade. Given a single reference slug or a state filter, it advances the matching refs from candidate toward page1_validated through the FSM, with strict page 1 anti-homonymy validation.

Anchors all downloads in the local registry (pdf_path, pdf_sha256, acquisition_attempts[]) so the curator can audit everything.

When to invoke

Trigger this skill for any of:

  • The user wants to fetch a PDF for a ref by slug
  • The user wants to push the whole batch of candidate or uid_resolved refs forward
  • The user explicitly calls /paper-trail:cascade, /paper-trail:reactivate-ocr, or /paper-trail:status
  • sota-writer sub-task needs PDFs acquired for its proposed candidates

Do NOT invoke for semantic decisions (is this citation correct?) — that belongs to sota-auditor.

How it works

The skill delegates to the worker B Python CLI:

# Single ref by slug
python -m pipeline run --ref <slug>

# Batch by state filter
python -m pipeline run --state candidate --limit 50

# Dry-run (no mutation)
python -m pipeline run --state candidate --dry-run

# Reactivate refs waiting for OCR
python -m pipeline reactivate-ocr

The CLI invokes the 8-source cascade (10 with RESEARCH_ENABLE_SHADOW_LIBS=1 — see DISCLAIMER.md — and 11 when the browser route is available too, see docs/ACQUISITION_HEADFUL.md). Each acquired PDF must pass page 1 validation (author + title similarity ≥ 0.3 + zero off-domain keywords) before being accepted into the registry.

Cascade order (default, without shadow libs)

1. Crossref OA       (DOI-based, open-access metadata)
2. arXiv             (preprints CS/math/physics/q-bio/q-fin/etc.)
3. OpenAlex          (cross-domain academic graph)
4. Unpaywall         (OA discovery, fallback)
5. HAL               (Hyper Articles en Ligne, French academia)
6. CORE              (UK-based open repository aggregator)
7. archive.org       (digitized books and articles)
8. WebSearch queue   (manual fallback — adds the ref to a queue for
                     human-driven search via Claude Code interactive)

Read the full file on GitHub · 223 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. 6d ago First seen · 223 lines · 266 tokens per session scan A 39fc7ef6bd33

Subscribe to this mod's changes

pdf-cascade is a skill published in the GitHub repository roomi-fields/paper-trail (5 stars, last pushed 2d ago), licensed MIT. It adds 266 tokens to every session and 2,037 once invoked, about $0.0013 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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