add-lang

add-lang is a skill for Claude Code, Codex from SolvingLab/OmniWeave. It costs 79 tokens per session (3,030 once invoked), scanned A, a copy of add-lang, MIT.

A workflow for adding support for a new programming language to OmniWeave, a code-extraction and search system that uses tree-sitter grammars to understand source files.

In plain words
What is it for?
It helps connect a language grammar, extract code symbols, write tests, benchmark results on real projects, and update documentation.
Why use it?
It ensures the new language is wired through the full extraction pipeline and tested on real repositories instead of being added only superficially.

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/solvinglab/omniweave/add-lang
Any agent
npx skills add SolvingLab/OmniWeave --skill add-lang
Clone the repo
git clone --depth 1 https://github.com/SolvingLab/OmniWeave

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-lang

README.md
[![agentmods](https://agentmods.dev/badge/skills/solvinglab/omniweave/add-lang.svg)](https://agentmods.dev/skills/solvinglab/omniweave/add-lang)
Your own site
<a href="https://agentmods.dev/skills/solvinglab/omniweave/add-lang"><img src="https://agentmods.dev/badge/skills/solvinglab/omniweave/add-lang.svg" alt="Measured on agentmods" height="20"></a>
Per session 79 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,030 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. Scan, not verified.
Origin 97% copy Near-identical to another mod 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 $0.00079 $0.03030
Opus 5 $0.00039 $0.01515
Sonnet 5 $0.00016 $0.00606
Haiku 4.5 $0.00008 $0.00303

Measured 3d ago against content hash d6127863387e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

add-lang 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 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.

Makes network callslowCapability

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

classes/structs, imports, enums; or `curl` a raw file from a known repo), then:
Origin

This is a copy

97% identical to add-lang — 32 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/add-lang/SKILL.md · 220 lines

How it starts

The opening of the file, as written. The whole thing — 220 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Add a language to OmniWeave

Wire a new tree-sitter language into omniweave's extraction pipeline, prove it extracts real symbols on popular repos, and prove it beats no-omniweave for an agent. Runs fully autonomously — pick repos, benchmark, update docs, then report. Never commit, push, publish, or tag (house rule); leave all changes for the user to review.

The argument is the language token used throughout the Language union, e.g. lua, elixir, zig. If none was given, ask which language. Use the lowercase single-token form everywhere (csharp, not c#).

Prerequisites

  • Run from the omniweave repo root. node, git, gh, and a logged-in Codex CLI (the benchmark spawns real Codex -p runs).
  • The benchmark uses the local dev build — Step 8 builds + links it on PATH.

Workflow

Copy this checklist and work through it in order:

- [ ] 1. Resolve language; bail early if already supported (just benchmark)
- [ ] 2. Find a grammar + health-check it (ABI / heap corruption)
- [ ] 3. Discover the grammar's AST node types (dump-ast.mjs)
- [ ] 4. Wire the language (4 files; sometimes a 5th core touch)
- [ ] 5. Build + verify-extraction loop until PASS
- [ ] 6. Add extraction tests; make them green
- [ ] 7. Auto-pick 3 popular repos by size tier; add to corpus.json
- [ ] 8. Benchmark all 3: extraction + with/without A/B
- [ ] 9. Update README + CHANGELOG
- [ ] 10. Report; do NOT commit

Step 1 — Resolve + short-circuit

Check whether the language is already wired: look for the token in the LANGUAGES const (src/types.ts) and the EXTRACTORS map (src/extraction/languages/index.ts). If it is already supported (e.g. typescript, rust), skip Steps 2–6 and go straight to benchmarking (Steps 7–8) to validate/measure it — note in the report that no code changed.

Step 2 — Find a grammar, then health-check it

ls node_modules/tree-sitter-wasms/out/ | grep -i <lang>   # csharp -> c_sharp
  • Present → likely off-the-shelf; grammars.ts resolves it from tree-sitter-wasms automatically. (Many languages: elixir, zig, ocaml, solidity, toml, yaml, …)
  • Absent → vendor a .wasm into src/extraction/wasm/ (like pascal / scala / lua) and add the token to the vendored branch in Step 4.

Read the full file on GitHub · 220 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 · 220 lines · 79 tokens per session scan A d6127863387e

Subscribe to this mod's changes

add-lang is a skill published in the GitHub repository SolvingLab/OmniWeave (0 stars, last pushed 2mo ago), licensed MIT. It adds 79 tokens to every session and 3,030 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 97% identical to add-lang, differing in 32 lines, and is treated as a copy.

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