feat: Add Multichain API to Flask

[ffmcgee725]

Description

This branch adds support for the Multichain API to the Flask build of the Extension.

The existing API (via injected provider) should be completely unchanged.

(Very Briefly) What is the MetaMask Multichain API

• Concurrent connection to any number of chains (no network switching)
• Unified entry point for all chain ecosystems (EVM, BTC, Solana, Cosmos, Polkadot etc)
• Accessible via window.postMessage(). Not accessible via an injected global like window.ethereum

Key Documents/Standards

mip = MetaMask Improvement Proposal

• MIP-5 (Overview of the Multichain API)
  • CAIP-25 (new connection request API)
  • CAIP-27 (new request API, envelope with target scope/chainId included)
• MIP-6 (Overview of how the Multichain API’s EVM support diverges from the 1193 injected provider)

Manual testing steps

(RECOMMENDED) Use the Multichain Test Dapp
NOTE: window.postMessage should be used as extensionId for mobile.

• Video Demo for Interacting w/ Multichain Test Dapp

OR

yarn setup:flask

Then

yarn start:android:flask

or

yarn start:ios:flask

Setup event listener via dev tools

window.addEventListener('message', (event) => {
  const {
    target,
    data
  } = event.data;
  if (
    target !== "metamask-inpage" ||
    data?.name !== 'metamask-multichain-provider'
  ) {
    return;
  }
  console.log(data.data)
})

Send a multichain API request via dev tools

const caipPostMessage = (data) => {
  window.postMessage({
    target: 'metamask-contentscript',
    data: {
      name: 'metamask-multichain-provider',
      data
    }
  }, location.origin)
}

// create session
caipPostMessage({
    jsonrpc: '2.0',
    method: 'wallet_createSession',
    params: {
      optionalScopes: {}
    }
})

// get session
caipPostMessage({
    jsonrpc: '2.0',
    method: 'wallet_getSession',
    params: {}
})

// revoke session
caipPostMessage({
    jsonrpc: '2.0',
    method: 'wallet_revokeSession',
    params: {}
})

// invoke method
caipPostMessage({
    jsonrpc: '2.0',
    method: 'wallet_invokeMethod',
    params: {
            scope: 'eip155:1',
            request: {
                "method": "eth_blockNumber",
                "params": [],
            }
        }
})

More detailed example of manual requests

taken from extension equivalent Add Multichain API to Flask work

Pre-merge author checklist

• I’ve followed MetaMask Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

Bitrise

🔄🔄🔄 pr_smoke_e2e_pipeline started on Bitrise...🔄🔄🔄

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• This comment will auto-update when build completes
• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[sonarqubecloud]

Quality Gate failed

Failed conditions
38.5% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[metamaskbot]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: 529a01b
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/bbbb5e79-b60f-4656-8b0c-07c871e0fbd6

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[Prithpal-Sooriya]

Smoked skipped due to a flakey test with Notifications.
Validated that this should not block this PR

CC @MetaMask/notifications