setup-browser-app

Instructions for connecting a plain JavaScript or TypeScript browser app to Phantom without using a web framework.

In plain words
What is it for?
Use it to install the browser SDK, create one shared client, connect users, and read Solana or Ethereum-compatible accounts.
Why use it?
It gives a consistent setup for connecting and disconnecting wallets and avoids duplicating the wallet client across the app.

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/phantom/phantom-agent-kit/setup-browser-app
Any agent
npx skills add phantom/phantom-agent-kit --skill setup-browser-app
Clone the repo
git clone --depth 1 https://github.com/phantom/phantom-agent-kit

Made for: Claude Code, Codex.

Per session 24 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 665 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 $0.00024 $0.00665
Opus 5 $0.00012 $0.00332
Sonnet 5 $0.00005 $0.00133
Haiku 4.5 $0.00002 $0.00067

Measured 2d ago against content hash 768f04db00c1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

setup-browser-app 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 2d 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/setup-browser-app/SKILL.md · 113 lines

How it starts

The opening of the file, as written. The whole thing — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Scaffold Browser App with Phantom Connect

When to use

  • User asks to set up a vanilla JS app with Phantom Connect
  • User wants to create a framework-agnostic wallet integration
  • User wants to use the Browser SDK directly

Workflow

Step 1: Install Dependencies

npm install @phantom/browser-sdk @solana/web3.js

Step 2: Create the SDK Singleton

Initialize a single BrowserSDK instance for your application:

import { BrowserSDK, AddressType } from "@phantom/browser-sdk";

const sdk = new BrowserSDK({
  appId: "your-app-id-from-phantom-portal",
  providers: ["google", "apple"],
  addressTypes: [AddressType.Solana, AddressType.Ethereum],
});

Important: Create only ONE BrowserSDK instance per application. Reuse this singleton everywhere.

Step 3: Implement Connect / Disconnect

async function connectWallet() {
  try {
    const accounts = await sdk.connect();
    console.log("Connected accounts:", accounts);

    const solanaAccount = accounts.find((a) => a.chain === "solana");
    if (solanaAccount) {
      console.log("Solana address:", solanaAccount.address);
    }
  } catch (error) {
    console.error("Connection failed:", error);
  }
}

async function disconnectWallet() {
  try {
    await sdk.disconnect();
    console.log("Disconnected");
  } catch (error) {
    console.error("Disconnect failed:", error);
  }
}

Step 4: Access Chain-Specific APIs

Use sdk.solana for Solana operations and sdk.ethereum for EVM operations:

// Solana operations
const solana = sdk.solana;

// Sign and send a transaction
const { signature } = await solana.signAndSendTransaction(transaction);

// Sign a message
const { signature: msgSig } = await solana.signMessage(
  new TextEncoder().encode("Hello from Phantom!")
);

Step 5: Check Connection State

function isWalletConnected(): boolean {
  return sdk.isConnected;
}

function getAccounts() {
  return sdk.accounts;
}

Step 6: HTML Setup (Minimal Example)

Read the full file on GitHub · 113 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. 2d ago First seen · 113 lines · 24 tokens per session scan A 768f04db00c1

Subscribe to this mod's changes

setup-browser-app is a skill published in the GitHub repository phantom/phantom-agent-kit (11 stars, last pushed 14d ago), licensed MIT. It adds 24 tokens to every session and 665 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 2026-08-30.

Related

Other skills, from other repositories

general-video

Author or edit a custom HyperFrames composition when no specialized workflow fits, or when BRIEF.md sets flow: companion. Use for longer or multi-scene pieces, brand and sizzle reels, montages, static loops, static title cards, footage remixes, and freeform builds. Use motion-graphics instead for a short unnarrated…

heygen-com/hyperframes · 92 tokens

use-agent-browser-for-airi

Test AIRI display-model imports with agent-browser across stage-tamagotchi Electron, stage-web, and stage-pocket mobile web layouts. Use when uploading and verifying contributor-supplied Live2D ZIP, VRM, or MMD ZIP/PMX/PMD files through AIRI's model selector, including onboarding bypass, format-specific import…

moeru-ai/airi · 87 tokens

opencli-sitemap-author

Use when creating or maintaining OpenCLI site sitemaps: agent-facing navigation, page-state, action, workflow, API-reference, pitfall, and fallback knowledge for a website. Use after browser exploration discovers durable site context, when a sitemap is stale, or when promoting local site knowledge into the repo.

jackwener/OpenCLI · 67 tokens

debug-optimize-lcp

Guides debugging and optimizing Largest Contentful Paint (LCP) using Chrome DevTools MCP tools. Use this skill whenever the user asks about LCP performance, slow page loads, Core Web Vitals optimization, or wants to understand why their page's main content takes too long to appear. Also use when the user mentions…

ChromeDevTools/chrome-devtools-mcp · 99 tokens

pinchtab-mcp

Use this skill when a task requires browser automation through PinchTab's MCP server connected to a remote browser instance. Covers navigation, element interaction, data extraction, form filling, multi-step flows, and session management via MCP tools.

pinchtab/pinchtab · 52 tokens

mintlify-preview

Run the public Mintlify product docs site locally for live preview. Use when previewing or iterating on docs under docs/ (.mdx/.md pages, docs.json nav), or when the user says "start the docs", "run mintlify", "preview the docs site".

latitude-dev/latitude-llm · 69 tokens