add-language

add-language is a skill for Claude Code, Codex from leifericf/agentic-sdk. It costs 18 tokens per session (868 once invoked), scanned A, original, MIT.

A meta-tool for adding writing guidance for a programming language not already covered by the project's standard set. It gathers project-specific details, generates a recipe, connects it to the project descriptor, and validates the result.

In plain words
What is it for?
Use it when a real project ships code in C, Zig, Clojure, Elixir, or another language outside the curated set and needs tailored writing guidance.
Why use it?
It fills a documented language-support gap only when the project actually uses that language.

Skill for Claude CodeCodex

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/leifericf/agentic-sdk/add-language
Any agent
npx skills add leifericf/agentic-sdk --skill add-language
Clone the repo
git clone --depth 1 https://github.com/leifericf/agentic-sdk

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.

agentmods badge for add-language

README.md
[![agentmods](https://agentmods.dev/badge/skills/leifericf/agentic-sdk/add-language.svg)](https://agentmods.dev/skills/leifericf/agentic-sdk/add-language)
Your own site
<a href="https://agentmods.dev/skills/leifericf/agentic-sdk/add-language"><img src="https://agentmods.dev/badge/skills/leifericf/agentic-sdk/add-language.svg" alt="Measured on agentmods" height="20"></a>
Per session 18 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 868 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 $0.00018 $0.00868
Opus 5 $0.00009 $0.00434
Sonnet 5 $0.00004 $0.00174
Haiku 4.5 $0.00002 $0.00087

Measured 3d ago against content hash 9d2efa2518c5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

add-language 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 3d 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/add-language/SKILL.md · 76 lines

How it starts

The opening of the file, as written. The whole thing — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.

add-language

Role: the language meta-skill. Generate a draft write- recipe from the skeleton for a language outside the curated set (C, Zig, Clojure, Elixir), and wire it into the descriptor.

Prerequisites

~/.agentic-sdk/<project>/project.edn exists (run bootstrap-project first). The new language is outside the curated four (C, Zig, Clojure, Elixir). A real project need for the language, not speculative.

Procedure

Follow the shared add-* procedure in docs/design.md section 8.3: detect the gap, interview for the skeleton's variable slot, generate against the skeleton, wire into the descriptor, validate.

  1. Detect the gap. Confirm the language is outside #{:c :zig :clojure :elixir} and that the project actually ships code in it. A speculative add is a finding, not an action.
  2. Interview for the discipline slot. Ask one batch of at most three questions for what the write- skeleton's discipline slot needs: how the language expresses Functional Core / Imperative Shell, the failure model (errors as values, exceptions, result types), and the rigor that distinguishes correct code in this language (allocation, lifetimes, concurrency, the native edge when applicable). The skeleton fills four anchors and a numbered procedure per docs/design.md section 6; the discipline slot is the only part that varies.
  3. Generate the recipe. Author skills/write-<lang>/SKILL.md from the skeleton: frontmatter (name: write-<lang>, model-invoked), the four anchors (the style-standard file, the architecture contract in skills/shared/references/architecture.md, the placement source from the descriptor's module map, the ADR log), and the numbered procedure (place it, then language discipline, then failure model, then verify like the lanes). Tests-first; terse comments; the public-text rule from skills/shared/references/prose-style.md. Reference FC/IS and the native-edge doctrine in architecture.md instead of restating them.
  4. Wire the descriptor. Add the language keyword to :languages in ~/.agentic-sdk/<project>/project.edn. If the language brings a native edge, set :architecture :native-edge? true and add the native-edge citation. Add the language's lane commands to :lanes :cheap, :wave, and :pre-land (formatter, build, test, release gate).
  5. Validate. Run one sample write and one review round using the new recipe: a writer writes a small unit, a reviewer runs the active dimensions over it. The recipe earns its place when the unit lands clean and the review finds nothing the recipe should have caught. Adjust the discipline slot from what the validation surfaced.
  6. Land. One commit, category Skills:.

Read the full file on GitHub · 76 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. 3d ago First seen · 76 lines · 18 tokens per session scan A 9d2efa2518c5

Subscribe to this mod's changes

add-language is a skill published in the GitHub repository leifericf/agentic-sdk (5 stars, last pushed 2d ago), licensed MIT. It adds 18 tokens to every session and 868 once invoked, about $0.0001 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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