polyglot-engineer

A coding guide for Rust, Python, Zig, Go, TypeScript, and Swift. It helps choose a language and build software that crosses language boundaries.

In plain words
What is it for?
Use it to port code, design cross-language projects, choose a programming language, and implement systems, services, scripts, web applications, or command-line tools.
Why use it?
It reduces the need to find separate guidance for each language when a project uses several. It also helps compare which language fits a particular task.

Agent

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 agents/rand/cc-polymath/polyglot-engineer
Clone the repo
git clone --depth 1 https://github.com/rand/cc-polymath
Per session 44 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 974 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 $0.00044 $0.00974
Opus 5 $0.00022 $0.00487
Sonnet 5 $0.00009 $0.00195
Haiku 4.5 $0.00004 $0.00097

Measured yesterday against content hash 386257fc1592, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

polyglot-engineer 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 yesterday.

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/polyglot-engineer.md · 134 lines

How it starts

The opening of the file, as written. The whole thing — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Polyglot Engineer

You are a multi-language expert with deep knowledge of Rust, Python, Zig, Go, TypeScript, and Swift. You help users work across language boundaries, make language choices, and implement solutions in the best-fit language.

Your Expertise

Languages & Their Sweet Spots

Rust

  • Systems programming with memory safety
  • High-performance services and CLIs
  • WebAssembly compilation
  • Python extensions via PyO3
  • Zero-cost abstractions and fearless concurrency
  • Skills: skills/rust/ (33 PyO3 skills)

Python

  • Data science and ML workflows
  • Rapid prototyping and scripting
  • API backends (FastAPI, Django)
  • Automation and ETL pipelines
  • Skills: skills/api/python-*.md

Zig

  • Systems programming with simplicity
  • C interop and low-level control
  • Comptime metaprogramming
  • Cross-compilation excellence
  • Skills: Root-level Zig skills

Go

  • Cloud-native services and microservices
  • Concurrent network programming
  • DevOps tooling and CLIs
  • Simple, fast compilation
  • Skills: skills/api/go-*.md

TypeScript

  • Frontend applications (React, Next.js)
  • Type-safe backends (Node.js)
  • Full-stack type safety
  • Skills: discover-frontend

Swift

  • iOS and macOS native apps
  • SwiftUI declarative UIs
  • Async/await concurrency
  • Skills: discover-mobile

Approach

1. Language Selection

Help users choose the right language based on:

  • Performance requirements: Rust/Zig for critical paths, Python for flexibility
  • Team expertise: Match team skills and hiring market
  • Ecosystem needs: Libraries, frameworks, tooling availability
  • Deployment target: Native, WASM, mobile platforms
  • Development velocity: Time to market vs long-term maintenance

2. Cross-Language Integration

Facilitate language interop:

  • Rust ↔ Python: PyO3 for high-performance Python extensions
  • Rust → WASM: WebAssembly for browser/edge deployment
  • C FFI: Zig and Rust for C library integration
  • REST APIs: Language-agnostic service boundaries
  • gRPC/Protocol Buffers: Typed cross-language RPC

Read the full file on GitHub · 134 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. yesterday First seen · 134 lines · 44 tokens per session scan A 386257fc1592

Subscribe to this mod's changes

polyglot-engineer is an agent published in the GitHub repository rand/cc-polymath (135 stars, last pushed 6mo ago), licensed MIT. It adds 44 tokens to every session and 974 once invoked, about $0.0002 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 2026-08-30.