ContextWeaver: Skill for Claude Code

.agents/skills/trellis-before-dev/SKILL.md

trellis-before-dev is a skill for Claude Code, Codex from hsingjui/ContextWeaver. It costs 70 tokens per session (592 once invoked), scanned A, original, MIT.

A preparation workflow that finds the coding rules relevant to a task in a project's `.trellis/spec/` files. It reads task documents, identifies the affected package and layer, and follows the applicable checklists.

In plain words
What is it for?
Use it before writing code, when switching packages, or when you need to discover the project's development instructions for a task.
Why use it?
It reduces the chance of starting work with the wrong project conventions or missing required design, testing, and shared guidelines.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is hsingjui/ContextWeaver's own configuration. It tells Claude Code and Codex how to work on ContextWeaver itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ContextWeaver configures →

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python3 ./.trellis/scripts/get_context.py --mode packages.

Reuse

Borrowing it

Nothing to install: this file belongs to hsingjui/ContextWeaver. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/hsingjui/ContextWeaver/main/.agents/skills/trellis-before-dev/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/hsingjui/ContextWeaver

Made for: Claude Code, 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.

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README.md
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Your own site
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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.

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Your own site · 80×15
<a href="https://agentmods.dev/skills/hsingjui/contextweaver/trellis-before-dev"><img src="https://agentmods.dev/badge/skills/hsingjui/contextweaver/trellis-before-dev.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 70 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 592 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.
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 $0.00070 $0.00592
Opus 5.5 $0.00028 $0.00237
Sonnet 5.5 $0.00014 $0.00118
Haiku 4.5 $0.00007 $0.00059

Measured 1mo ago against content hash 00c9d1c83bc3, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

trellis-before-dev 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 1mo 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.

.agents/skills/trellis-before-dev/SKILL.md · 52 lines

What it actually says

Read the relevant development guidelines before starting your task.

Execute these steps:

  1. Read current task artifacts:

    • prd.md for requirements and acceptance criteria
    • design.md if present for technical design
    • implement.md if present for execution order and validation plan
  2. Discover packages and their spec layers:

    python3 ./.trellis/scripts/get_context.py --mode packages
    
  3. Identify which specs apply to your task based on:

    • Which package you're modifying (e.g., cli/, docs-site/)
    • What type of work (backend, frontend, unit-test, docs, etc.)
    • Any spec/research paths referenced by the task artifacts
  4. Read the spec index for each relevant module:

    cat .trellis/spec/<package>/<layer>/index.md
    

    Follow the "Pre-Development Checklist" section in the index.

  5. Read the specific guideline files listed in the Pre-Development Checklist that are relevant to your task. The index is NOT the goal — it points you to the actual guideline files (e.g., error-handling.md, conventions.md, mock-strategies.md). Read those files to understand the coding standards and patterns.

  6. Always read shared guides:

    cat .trellis/spec/guides/index.md
    
  7. For a non-trivial task, state the change boundary before writing code. Non-trivial means it touches more than one file, crosses a layer, changes a public interface, or edits code you did not just write. Write down:

    • the smallest behavior gap between what happens now and what should happen
    • where that behavior actually lives (not where it is easiest to intercept)
    • which files you expect to change, and why each one is necessary
    • what you are explicitly not doing in this task
    • if a local refactor is needed, how you will show it did not change behavior

    A small, well-scoped change does not need this — do it directly.

    If the real scope turns out to be clearly larger than this, say so and why before continuing. Do not widen the change on your own.

  8. Understand the coding standards and patterns you need to follow, then proceed with your development plan.

This step is mandatory before writing any code.

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. 1mo ago First seen · 52 lines · 70 tokens per session scan A 00c9d1c83bc3

Subscribe to this mod's changes

trellis-before-dev is a skill published in the GitHub repository hsingjui/ContextWeaver (297 stars, last pushed 1mo ago), licensed MIT. It adds 70 tokens to every session and 592 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-09-07.

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