Chain 138 Snap adds DeFi Oracle Meta Mainnet (ChainID 138) and ALL Mainnet (651940) support inside MetaMask: network params, token list, market data, swap quotes, and bridge routes (CCIP and Trustless).

MetaMask already supports Chain 138 as a custom EVM network, but native Swaps, Portfolio Bridge, and USD pricing do not include Chain 138. This Snap provides in-wallet swap quotes, bridge routes, and market data by calling your token-aggregation (or compatible) API.

Install

Install MetaMask (extension or mobile).
From a dApp or the companion site, connect and add the Snap using the ID below.

Snap ID: npm:chain138-snap

Usage

dApps invoke the Snap via the MetaMask provider:

// Connect / install the Snap (your dApp typically does this once)
await ethereum.request({
  method: 'wallet_requestSnaps',
  params: {
    'npm:chain138-snap': {},
  },
});

// Call a method (e.g. get networks or market data)
const result = await ethereum.request({
  method: 'wallet_invokeSnap',
  params: {
    snapId: 'npm:chain138-snap',
    request: {
      method: 'get_networks',
      params: { apiBaseUrl: 'https://your-token-aggregation-api.com' },
    },
  },
});

For market data, swap quotes, and bridge routes, the dApp must pass apiBaseUrl (your token-aggregation service base URL) in the request params. Optional URL params: networksUrl, tokenListUrl, bridgeListUrl.

RPC methods

Method	Description
`hello`	Basic test; returns a greeting.
`get_networks`	Full EIP-3085 chain params (Chain 138, Ethereum, ALL Mainnet).
`get_chain138_config`	Chain 138 config from API.
`get_chain138_market_chains`	Market chains list.
`get_token_list` / `get_token_list_url`	Token list (optional `chainId`).
`get_oracles`	Oracles config.
`show_dynamic_info`	In-Snap dialog with networks and token list URL.
`get_market_summary` / `show_market_data`	Tokens and USD prices.
`get_bridge_routes` / `show_bridge_routes`	CCIP and Trustless bridge routes.
`get_swap_quote` / `show_swap_quote`	Swap quote (requires `tokenIn`, `tokenOut`, `amountIn`).

Repository and docs

Source: github.com/bis-innovations/chain138-snap
Integrator guide: INTEGRATORS.md (Snap ID, apiBaseUrl, optional URLs)
Testing / publishing: TESTING_INSTRUCTIONS.md, PUSH_AND_PUBLISH.md

License

MIT-0 OR Apache-2.0