contextcrumb

contextcrumb is a skill for Codex from Yuchen20/Context-Crumb. It costs 43 tokens per session (1,475 once invoked), scanned A, original, MIT.

A tool that shortens large local text files before they are given to an AI assistant. For source code, it keeps executable code unchanged and compresses only comments and documentation strings.

In plain words
What is it for?
For preparing documentation, notes, transcripts, research material, logs, and supported source files for AI-assisted work. It can also load text from folders in batches or samples.
Why use it?
Long documents, notes, logs, or transcripts can use up the assistant’s context space. Compressing prose leaves more room for the actual task while preserving code behavior.

Skill for Codex

Written for Codex: agents/openai.yaml present.

Good fit For preparing documentation, notes, transcripts, research material, logs, and supported source files for AI-assisted work. It can also load text from folders in batches or samples.

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Install with agentmods
npx agentmods add skills/yuchen20/context-crumb/contextcrumb
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 Yuchen20/Context-Crumb --skill contextcrumb
Clone the repo
git clone --depth 1 https://github.com/Yuchen20/Context-Crumb

Made for: Codex.

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 contextcrumb

README.md
[![agentmods](https://agentmods.dev/badge/skills/yuchen20/context-crumb/contextcrumb.svg)](https://agentmods.dev/skills/yuchen20/context-crumb/contextcrumb)
Your own site
<a href="https://agentmods.dev/skills/yuchen20/context-crumb/contextcrumb"><img src="https://agentmods.dev/badge/skills/yuchen20/context-crumb/contextcrumb.svg" alt="Measured on agentmods" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,475 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00043 $0.01475
Opus 5 $0.00022 $0.00737
Sonnet 5 $0.00009 $0.00295
Haiku 4.5 $0.00004 $0.00147

Measured 8d ago against content hash 18e7f3d75820, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

contextcrumb scanned grade A with 1 finding 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl https://huggingface.co/spaces/ymao20/contextcrumb-32m-demo/agents.md
agent/skills/contextcrumb/SKILL.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ContextCrumb

Use ContextCrumb when large prose-heavy text would otherwise bloat the context window. It can also load supported source files safely in auto mode: executable code is preserved exactly, and only comments/docstrings are compressed. The compressed output is the working context, not a preview.

Do not read large candidate files with cat, Get-Content, type, or similar raw file dumps before compression. Inventory names first, then use contextcrumb load to read compressed context when the CLI is available.

Use For

  • Documentation, Markdown, notes, transcripts, threads, logs, and research dumps
  • Prose-heavy local text where compression is acceptable before LLM reading
  • Supported source files when comment/docstring compression is useful and exact executable code must remain intact
  • Folders of natural-language text files when you need sampled or batched context loading

Do Not Use For

  • Unsupported source files, diffs, configs, schemas, commands, or structured data
  • Legal text, policy text, contracts, or compliance material
  • Any task that requires exact syntax, exact wording, exact formatting, or precise quotes

Quick Workflow

Decision tree:

  1. If reading a large local prose file, use local ContextCrumb.
  2. If reading a supported code file, use local ContextCrumb in default auto mode or --content-mode code-comments; then read raw source before exact edits.
  3. If local ContextCrumb is unavailable and the user provided pasted, non-sensitive text, use the hosted trial.
  4. If local ContextCrumb is unavailable and the input is a local or private file, ask the user to install local ContextCrumb.
  5. If exact wording, syntax, formatting, or every token matters, do not compress.

Inventory without reading file bodies:

rg --files <directory>

Check the CLI:

contextcrumb --help

If it is not on PATH, try the module form before installing:

python -m contextcrumb --help

If the project visibly uses an active virtual environment or tool-managed Python command, use that environment's normal command form rather than installing globally.

Read the full file on GitHub · 161 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 161 lines · 43 tokens per session scan A 18e7f3d75820

Subscribe to this mod's changes

contextcrumb is a skill published in the GitHub repository Yuchen20/Context-Crumb (1 stars, last pushed 3mo ago), licensed MIT. It adds 43 tokens to every session and 1,475 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.