Multithreading

What it does

When your agent uses it

• Running JavaScript on multiple threads
• Offloading heavy computation from the JS thread
• Communicating between runtimes
• Sharing data across threads

Example prompts

• “worklet”
• “worklets”
• “react-native-worklets”
• “/multithreading”

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

1. 1Read the user's package.json to find the installed react-native-worklets version.
2. 2Run npm view react-native-worklets version to get the latest published version.
3. 3If the installed version is older than the latest, inform the user and recommend upgrading before proceeding with implementation advice.

What it can do on your machine

Read from SKILL.md and the folder at commit 9e4e186. 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

  Shell commands in SKILL.md call:

  • npm

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

• Network

  No URLs in SKILL.md. Its commands use npm, which can reach the network depending on how they are called.

  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

Multithreading loads about 1.1k tokens when it runs. Until then it costs about 174 tokens; SKILL.md has 332 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~174

When it runs · the whole SKILL.md, loaded when a task matches

~1.1k

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

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 kingstinct/react-native-healthkit at commit 9e4e186, republished under its MIT licence (© kingstinct). 332 words, ~1,105 tokens.

name

multithreading

description

Software Mansion's best practices for multithreading in React Native apps using react-native-worklets. Use when running JavaScript on multiple threads, offloading heavy computation from the JS thread, communicating between runtimes, or sharing data across threads. Trigger on: 'worklet', 'worklets', 'react-native-worklets', 'runOnUI', 'runOnJS', 'scheduleOnUI', 'scheduleOnRN', 'scheduleOnRuntime', 'createWorkletRuntime', 'background thread', 'UI thread', 'worker runtime', 'Serializable', 'Synchronizable', 'multithreading', 'parallel execution', 'offload computation', 'background processing', 'Bundle Mode', or any request to move work off the JS thread in a React Native app.

What does the work need?
├── Respond to native events or drive animations on the same frame?
│   └── UI Runtime (main thread, one per app)
├── Heavy computation, data processing, or background tasks?
│   └── Worker Runtime (custom thread, many per app)
└── Access React state, navigation, or RN APIs?
    └── RN Runtime (JS thread, one per app)

Need to run code on a different runtime?
├── Fire-and-forget (no return value needed)?
│   ├── Target is UI Runtime  → scheduleOnUI(fn, ...args)
│   ├── Target is RN Runtime  → scheduleOnRN(fn, ...args)
│   └── Target is Worker      → scheduleOnRuntime(runtime, fn, ...args)
├── Need the return value asynchronously (Promise)?
│   ├── Target is UI Runtime  → await runOnUIAsync(fn, ...args)
│   └── Target is Worker      → await runOnRuntimeAsync(runtime, fn, ...args)
└── Need the return value synchronously (blocks caller)?
    ├── Target is UI Runtime  → runOnUISync(fn, ...args)
    └── Target is Worker      → runOnRuntimeSync(runtime, fn, ...args)

function computeOnUI() {
  'worklet';
  return 2 + 2;
}

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

Files

SKILL.md and 3 other files in .agents/skills/react-native-best-practices/references/multithreading of kingstinct/react-native-healthkit.

• SKILL.md
• setup-and-advanced.md
• shared-memory.md
• threading-api.md

Open the folder on GitHubat commit 9e4e186

Used in 1 other repository

We found 1 copy of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in kingstinct/react-native-healthkit, which our catalogue first saw on October 7, 2026.

• software-mansion-labs/skillsskills/react-native-best-practices/references/multithreading