audio

audio is a skill for Claude Code from ondrej-svec/heart-of-gold-toolkit. It costs 108 tokens per session (5,005 once invoked), scanned A, original, MIT.

An audio-production toolkit for turning text into speech, podcasts, voice clones, sound effects, dubbed audio, and isolated speech. It uses ElevenLabs through its Python SDK or command-line tool.

In plain words
What is it for?
Use it to create speech or multi-voice podcasts, list or clone voices, make sound effects, dub recordings, isolate audio, and play generated files.
Why use it?
It removes the need to build audio-generation scripts from scratch. It also sets rules for protecting API keys, previewing scripts, and avoiding common audio-generation problems.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the babel-fish plugin — 4 skills shipped together

Good fit Use it to create speech or multi-voice podcasts, list or clone voices, make sound effects, dub recordings, isolate audio, and play generated files.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ondrej-svec/heart-of-gold-toolkit/audio
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.

Any agent
npx skills add ondrej-svec/heart-of-gold-toolkit --skill audio
Clone the repo
git clone --depth 1 https://github.com/ondrej-svec/heart-of-gold-toolkit

Made for: Claude Code.

Or install babel-fish, the plugin that ships this one along with the rest of its 4 skills.

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 audio

README.md
[![agentmods](https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/audio/github.svg)](https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/audio)
Your own site
<a href="https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/audio"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/audio/github.svg" alt="Measured on agentmods" height="20"></a>

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.

agentmods 80×15 button for audio

Your own site · 80×15
<a href="https://agentmods.dev/skills/ondrej-svec/heart-of-gold-toolkit/audio"><img src="https://agentmods.dev/badge/skills/ondrej-svec/heart-of-gold-toolkit/audio.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 108 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,005 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 3 findings, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Rogue Agent · line 15
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
  • medium Rogue Agent · line 184
    Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.
    Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
  • medium Data Exfiltration · line 245
    Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
    Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
How audits are shown
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 $0.00108 $0.05005
Opus 5 $0.00054 $0.02502
Sonnet 5 $0.00022 $0.01001
Haiku 4.5 $0.00011 $0.00500

Measured 12d ago against content hash e8bb776efc34, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

audio 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 12d 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.

plugins/babel-fish/skills/audio/SKILL.md · 552 lines

How it starts

The opening of the file, as written. The whole thing — 552 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Audio Production

Generate audio — from single-line TTS to multi-voice podcasts. Currently powered by ElevenLabs. Includes ready-to-run Python scripts. Claude writes them to a temp file and executes directly.

Boundaries

This skill MAY: install the SDK, generate audio files, list voices, create voice clones, write and execute generation scripts, play audio.

This skill MAY NOT: store API keys in code (use env vars or ~/.elevenlabs/api_key), commit audio files to git, generate audio without user approval of the script first.

Common Rationalizations

Shortcut Why It Fails The Cost
Hardcode API key in script Leaks credentials to git history Security incident
Skip voice selection Default voice may not match content tone Wasted credits on re-gen
Generate full podcast without preview Long audio = expensive; mistakes compound Non-refundable credits
Import pydub for concatenation Broken on Python 3.13+ (audioop removed) Runtime crash
Use VoiceSettings with cloned voices Custom settings destabilize cloned voices Garbled/robotic audio
Use ... for pauses Causes hesitation/nervousness artifacts Unnatural stuttering
Use large chunks for long content Quality degrades in second half Robotic pacing
Skip language_code with accented speakers Model guesses language from accent Chinese/French mid-narration

Phase 0: Environment Setup

Entry: User wants audio content.

Step 1: Detect Authentication

Check in order — use the first one found:

# 1. Check CLI auth (preferred — already logged in)
elevenlabs auth whoami --no-ui 2>/dev/null

# 2. Check env var
echo "${ELEVENLABS_API_KEY:+set}"

# 3. Check stored key file
cat ~/.elevenlabs/api_key 2>/dev/null | head -c 10

API key resolution in Python (use this in ALL scripts):

import os

def get_api_key() -> str:
    """Resolve ElevenLabs API key from CLI store, env var, or fail."""
    key_file = os.path.expanduser("~/.elevenlabs/api_key")
    if os.path.exists(key_file):
        return open(key_file).read().strip()
    key = os.environ.get("ELEVENLABS_API_KEY", "")
    if key:
        return key
    raise RuntimeError(
        "No ElevenLabs API key found. Run `elevenlabs auth login` or "
        "set ELEVENLABS_API_KEY environment variable."
    )

Read the full file on GitHub · 552 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. 12d ago First seen · 552 lines · 108 tokens per session scan A e8bb776efc34

Subscribe to this mod's changes

audio is a skill published in the GitHub repository ondrej-svec/heart-of-gold-toolkit (19 stars, last pushed 22d ago), licensed MIT. It adds 108 tokens to every session and 5,005 once invoked, about $0.0005 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.

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