New: 98,000+ skills indexed from GitHub repos with 100+ stars · every skill safety-checkedBrowse top skillsTop skills
Esc to closeBrowse all skills
Submit a skillBrowse skills
Submit a skillBrowse skills

Agent skill

Masm Error Constants

by 0xMiden in 0xMiden/protocol

A skill your agent uses when adding or editing MASM assert / panic instructions — give every assertion a descriptive named error code.

MITAuto-check passedDevelopment

Install Masm Error Constants

skills CLI
$ npx skills add 0xMiden/protocol --skill masm-error-constants -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install 0xMiden/protocol masm-error-constants --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/0xMiden/protocol.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/masm-error-constants .claude/skills/masm-error-constants && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
masm-error-constants
GitHub stars
133
Token cost
~368 tokens
SKILL.md length
106 words
Files
1
Skills in repo
35
Repo updated
First seen
Licence
MIT

At a glance

A skill your agent uses when adding or editing MASM assert / panic instructions — give every assertion a descriptive named error code.

  • Editing MASM assert / panic instructions — give every assertion a descriptive named error code
  • SKILL.md covers Rule, Why and Examples
  • Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Masm Error Constants is an agent skill from 0xMiden/protocol. Use when adding or editing MASM assert / panic instructions — give every assertion a descriptive named error code.

Its SKILL.md is about 370 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Development. The repository describes itself as: Core components of the Miden protocol. The licence is MIT.

When your agent uses it

  • Editing MASM assert / panic instructions — give every assertion a descriptive named error code

Example prompts

  • “/masm-error-constants”

What it can do on your machine

Read from SKILL.md and the folder at commit 5f6a246. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    No scripts in the folder and no shell commands in SKILL.md (its code samples are masm).

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Masm Error Constants loads about 368 tokens when it runs. Until then it costs about 35 tokens; SKILL.md has 106 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~35
When it runs · the whole SKILL.md, loaded when a task matches
~368

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from 0xMiden/protocol at commit 5f6a246, republished under its MIT licence (© 0xMiden). 106 words, ~368 tokens.

Download SKILL.mdSave it as .claude/skills/masm-error-constants/SKILL.md (or your agent's skills folder).
name
masm-error-constants
description
Use when adding or editing MASM `assert*` / `panic` instructions — give every assertion a descriptive named error code.

MASM Error Constants

Rule

Every MASM assertion must carry a descriptive error code:

masm
assert.err=ERR_NOTE_NOT_FOUND
assert_eqw.err=ERR_COMMITMENT_MISMATCH

The error constant must:

  • Use the ERR_ prefix.
  • Live in the file's dedicated errors section (see masm-constants skill).
  • Have a descriptive string value, not a bare numeric code: const ERR_NOTE_NOT_FOUND = "note not found".
  • Be unique per distinct failure condition — do not share one ERR_ across two unrelated asserts.

Why

A bare assert traps with a generic message that tells the debugger nothing about which check failed; a descriptive ERR_ constant ties each trap site to a specific failure mode. Distinct constants per condition also let tests pin the expected error (see assert-specific-error-in-tests).

Examples

masm
# Good
const ERR_NOTE_NOT_FOUND = "note not found"
const ERR_COMMITMENT_MISMATCH = "stored commitment does not match recomputed value"

proc verify_note
    # ...
    assert.err=ERR_NOTE_NOT_FOUND
    # ...
    assert_eqw.err=ERR_COMMITMENT_MISMATCH
end

# Bad: bare assertion
proc verify_note
    assert
end

# Bad: shared generic constant for unrelated cases
const ERR_INVALID = "invalid"
assert.err=ERR_INVALID   # used in 6 places, each meaning something different

© 0xMiden, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in .claude/skills/masm-error-constants of 0xMiden/protocol.

Open the folder on GitHubat commit 5f6a246

Compare with similar skills

Masm Error Constants next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Masm Error Constants compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Masm Error Constants this skill0xMiden/protocol133—~368Automated safety check: PassMIT
Vercel Composition Patternssupabase/supabase111k58 repos~726Automated safety check: PassMIT
Finishing a Development Branchobra/superpowers297k5 repos~1.9kAutomated safety check: PassMIT
Typescript Advanced Typesrolling-scopes/rsschool-app10k25 repos~4.2kAutomated safety check: PassMPL-2.0
PR Babysitteropeninterpreter/openinterpreter69k3 repos~4.2kAutomated safety check: PassApache-2.0
Code Review ChecklistshareAI-lab/learn-claude-code78k5 repos~1.1kAutomated safety check: PassMIT

Similar skills

  • Vercel Composition Patterns

    supabase/supabase

    Official

    React composition patterns that scale. An agent skill from supabase/supabase.

    111k GitHub starsUsed in 58 repos~726 tokens
    DevelopmentAuto-check passed

  • Finishing a Development Branch

    obra/superpowers

    Walks the last step of a branch: confirm tests pass, detect the git environment, ask how to integrate, carry out your choice and clean up the worktree.

    297k GitHub starsUsed in 5 repos~1.9k tokens
    DevelopmentAuto-check passed

  • Typescript Advanced Types

    rolling-scopes/rsschool-app

    Master TypeScript's advanced type system including generics, conditional types, mapped types, template literals, and utility types for building type-safe applications.

    10k GitHub starsUsed in 25 repos~4.2k tokens
    DevelopmentAuto-check passed

  • PR Babysitter

    openinterpreter/openinterpreter

    Watches an open GitHub pull request until it merges, handling review comments, diagnosing CI failures and retrying flaky checks along the way.

    69k GitHub starsUsed in 3 repos~4.2k tokens
    DevelopmentAuto-check passed

  • Code Review Checklist

    shareAI-lab/learn-claude-code

    Reviews code against a five-part checklist covering security, correctness, performance, maintainability and testing, and reports findings in a fixed format.

    78k GitHub starsUsed in 5 repos~1.1k tokens
    DevelopmentAuto-check passed

  • Greploop

    onyx-dot-app/onyx

    Iteratively improves a PR (GitHub), MR (GitLab), or shelved changelist (Perforce) until Greptile gives it a 5/5 confidence score with zero unresolved comments.

    32k GitHub starsUsed in 4 repos~3.3k tokens
    DevelopmentAuto-check passed

More from 0xMiden/protocol

All 35 skills in this repo

  • Advice Provider Hygiene

    0xMiden/protocol

    A skill your agent uses when writing kernel, account, or note MASM code that reads from or writes to the advice provider (advice stack / advice map) — validate advice data.

    133 GitHub stars~1.1k tokensUpdated yesterday
    Auto-check passed

  • Cheap Masm Equivalents

    0xMiden/protocol

    A skill your agent uses when writing or reviewing MASM hot paths or loops — prefer the cheaper equivalent: loop counters and pointers on the operand stack instead of procedure locals, neq.0 over…

    133 GitHub stars~804 tokensUpdated yesterday
    Auto-check passed

  • Concise Changelog Entries

    0xMiden/protocol

    Keep CHANGELOG.md entries to a single concise sentence. An agent skill from 0xMiden/protocol.

    133 GitHub stars~805 tokensUpdated yesterday
    Auto-check passed

  • Concise PR And Issue Descriptions

    0xMiden/protocol

    Keep PR and issue descriptions short and decision-focused. An agent skill from 0xMiden/protocol.

    133 GitHub stars~1.8k tokensUpdated yesterday
    Auto-check passed

  • Conversion Method Naming

    0xMiden/protocol

    A skill your agent uses when naming a conversion or accessor method in Rust — follow the Rust API naming conventions for the method's cost and ownership.

    133 GitHub stars~450 tokensUpdated yesterday
    Auto-check passed

  • Decouple Component From Storage

    0xMiden/protocol

    A skill your agent uses when writing a generic MASM utility that accesses a caller-selected account storage slot — receive the slot as a parameter so the utility is portable across storage layouts.

    133 GitHub stars~529 tokensUpdated yesterday
    Auto-check passed

Categories

Questions about Masm Error Constants

What does Masm Error Constants do?

A skill your agent uses when adding or editing MASM assert / panic instructions — give every assertion a descriptive named error code. Masm Error Constants is an agent skill from 0xMiden/protocol. Use when adding or editing MASM assert / panic instructions — give every assertion a descriptive named error code.

When should I use Masm Error Constants?

Masm Error Constants fits situations like: editing MASM assert / panic instructions — give every assertion a descriptive named error code.

How do I install Masm Error Constants in Claude Code?

Run `npx skills add 0xMiden/protocol --skill masm-error-constants -a claude-code`. Or copy the skill folder (.claude/skills/masm-error-constants in 0xMiden/protocol) into .claude/skills/masm-error-constants in your project. Claude Code loads it when a task matches its description.

How do I install Masm Error Constants in Codex?

Run `npx skills add 0xMiden/protocol --skill masm-error-constants -a codex`. Or copy the skill folder (.claude/skills/masm-error-constants in 0xMiden/protocol) into .agents/skills/masm-error-constants in your project. Codex loads it when a task matches its description.

Can I use Masm Error Constants in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add 0xMiden/protocol --skill masm-error-constants -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/masm-error-constants, .gemini/skills/masm-error-constants, .github/skills/masm-error-constants and .opencode/skills/masm-error-constants in your project.

What does Masm Error Constants need to run?

SKILL.md names no scripts, command-line tools or credentials: Masm Error Constants is instructions for the agent only.

Does Masm Error Constants access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Masm Error Constants safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Masm Error Constants use?

Masm Error Constants is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Masm Error Constants use?

About 368 tokens (SKILL.md is roughly 1.5k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Masm Error Constants?

Skills that share tags, products or a category with Masm Error Constants: Vercel Composition Patterns (supabase/supabase, 111k stars), Finishing a Development Branch (obra/superpowers, 297k stars), Typescript Advanced Types (rolling-scopes/rsschool-app, 10k stars) and PR Babysitter (openinterpreter/openinterpreter, 69k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Masm Error Constants?

0xMiden (a GitHub organization) maintains it in 0xMiden/protocol, which has 133 GitHub stars. The repository holds 35 skills in this directory. The repository was last updated on October 8, 2026.

Source: 0xMiden/protocol on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.