multichain-session-lifecycle

multichain-session-lifecycle is a cursor rule for coding agents from MetaMask/metamask-connect-cursor-plugin. It costs 1,827 tokens per session, scanned A, original, MIT.

A set of rules for managing MetaMask Connect sessions across several blockchain networks. It covers shared client setup, connection requests, session data, events, timeouts, and permissions.

In plain words
What is it for?
Initialising the multichain client, preventing double connections, merging supported networks, handling wallet-session events, and responding to connection errors.
Why use it?
It prevents problems such as conflicting client settings, duplicate connection attempts, and incorrect handling of pending or expired sessions.

Cursor rule

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 rules/metamask/metamask-connect-cursor-plugin/multichain-session-lifecycle
Clone the repo
git clone --depth 1 https://github.com/MetaMask/metamask-connect-cursor-plugin

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 multichain-session-lifecycle

README.md
[![agentmods](https://agentmods.dev/badge/rules/metamask/metamask-connect-cursor-plugin/multichain-session-lifecycle.svg)](https://agentmods.dev/rules/metamask/metamask-connect-cursor-plugin/multichain-session-lifecycle)
Your own site
<a href="https://agentmods.dev/rules/metamask/metamask-connect-cursor-plugin/multichain-session-lifecycle"><img src="https://agentmods.dev/badge/rules/metamask/metamask-connect-cursor-plugin/multichain-session-lifecycle.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,827 This file is loaded in full into every session.
When invoked 1,827 The same file — it is already loaded in full.
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 $0.01827 $0.01827
Opus 5 $0.00914 $0.00914
Sonnet 5 $0.00365 $0.00365
Haiku 4.5 $0.00183 $0.00183

Measured 3d ago against content hash 3e706b81b186, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

multichain-session-lifecycle 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 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.

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.

rules/multichain-session-lifecycle.mdc · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Multichain Session Lifecycle

Singleton Merging

  • createMultichainClient is a singleton — calling it multiple times returns the same instance
  • On subsequent calls, new options merge into the existing instance
  • The dapp object from the first call is used for the client's lifetime — it is excluded from option merging entirely (later dapp values are ignored)
  • api.supportedNetworks entries merge by spreading the new map over the old — new chains are added and existing keys are overwritten by later calls
  • Call createMultichainClient once at app startup and store the returned client reference

Concurrent Connect Guard

  • Only one connect() call can be active at a time over MetaMask Wallet Protocol (MWP)
  • Calling connect() while a previous MWP connect() is pending throws a plain Error ("Existing connection is pending. Please check your MetaMask Mobile app to continue.") with no numeric code — match on the message. (-32002 is an extension-transport RPC-queue code, not an SDK error code)
  • Guard against double-clicks with a loading state or disable the connect button during connection
  • The original pending connect() promise will resolve once the user acts in MetaMask

Session Data Shape

  • Multichain connect() resolves with no value (Promise<void>) — session data arrives via the wallet_sessionChanged event or on demand from client.provider.getSession()
  • Session data is SessionData: scopes live under sessionScopes (e.g., session.sessionScopes['eip155:1'].accounts), and accounts are CAIP-10 strings (eip155:1:0x...)
  • sessionProperties may be present — if empty, it is undefined (not an empty object)
  • Always null-check sessionProperties before accessing its fields
  • Since @metamask/connect-evm 1.2.0, every wallet_createSession request issued by connect-evm attaches sessionProperties: { 'eip1193-compatible': true }. Sessions established through createEVMClient will surface this flag on the resolved session, letting wallets and analytics consumers distinguish EIP-1193-style connections from pure Multichain API connections or other provider types (e.g. Solana Wallet Standard). Do not rely on it being present for sessions created directly via the multichain client

Read the full file on GitHub · 98 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 · 98 lines · 1,827 tokens per session scan A 3e706b81b186

Subscribe to this mod's changes

multichain-session-lifecycle is a cursor rule published in the GitHub repository MetaMask/metamask-connect-cursor-plugin (2 stars, last pushed 2mo ago), licensed MIT. It adds 1,827 tokens to every session, about $0.0091 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 2026-08-31.