moss-wallet-cli

name	moss-wallet-cli
description	Use the MegaETH Wallet CLI to connect a MegaETH passkey wallet, create/manage scoped delegated session keys, inspect permissions, and use those keys for read-only calls, transfers, and relay-backed execution on MegaETH.

MegaETH Wallet CLI

Use this skill when an agent needs to operate a local MegaETH wallet through mega moss commands.

Mental Model

MegaETH Wallet CLI is not a root wallet or passkey manager. It is a local tool for creating, managing, and using scoped delegated session keys for a MegaETH wallet account.

• The wallet account is an EVM address on MegaETH controlled by the user's passkey wallet at account.megaeth.com.
• Commands default to mainnet. Add --network testnet when the user explicitly asks for testnet; local profiles are separate per network.
• mega moss login connects this CLI install to that wallet account and stores an account profile locally. It does not create a delegated session key.
• mega moss create-key generates a delegated key locally and asks the passkey wallet to approve a scoped session key for the same wallet account.
• Session keys can spend only within their approved expiry, token spend limits, fee allowance, and contract call scopes.
• The CLI signs with the delegated session key and submits writes through the MegaETH/Porto relay. It never has the user's passkey or root/admin key.
• mega moss revoke <key> revokes a delegated key on-chain.
• mega moss logout only deletes this CLI's local profile and delegated private key material.

Setup

If mega moss --help is unavailable, install the wallet CLI with the public installer:

curl -fsSL https://account.megaeth.com/install | sh

After install, make sure the install directory printed by the installer is on PATH, then rerun mega moss --help.

Release installs check for updates automatically.

Safety Rules

• Never print, log, request, or transmit private keys, bearer tokens, API keys, passkeys, WebAuthn material, or relay secrets.
• Treat profile files as local secrets. Never inspect profile files directly, including with cat, sed, rg, workspace-wide search, or editor reads, and do not copy profile contents into chat, issue comments, logs, or telemetry. Use mega moss whoami, mega moss list, mega moss permissions, and mega moss debug instead.
• Use mega moss call for read-only eth_call workflows.
• Use mega moss execute or mega moss transfer only when the user asked for a state-changing operation.
• Prefer --json for machine-readable output and -t only for compact text. Human mode may include TTY-only color or login stderr helpers.

Login And Browser Authorization

Run loopback login on the same machine as the browser:

mega moss login

The CLI opens MegaETH Wallet in the system browser, listens on 127.0.0.1:<random-port>/callback, validates state, and stores the approved account profile locally. The callback must not contain private keys or transferable bearer credentials. Login alone is not enough for writes; create a scoped delegated key before execute or transfer.

Prefer the default browser-opened loopback flow when the browser and CLI run on the same machine. Use --no-browser only as a fallback when the browser does not open automatically or when the user needs a URL to copy manually. --no-browser is not headless auth; it still uses same-machine loopback auth and waits for browser approval.

Use --auth-flow device only for headless or different-machine approval. The CLI prints a URL and verification code, the user approves in MegaETH Wallet, and the CLI polls the wallet API with PKCE until approval. --no-browser is unnecessary with device auth. If the CLI says device-code auth is unavailable, use loopback auth or a wallet backend that supports /v1/cli-auth/device.

Do not reuse old authorization URLs or edit their query parameters. If an auth command times out, is interrupted, or the browser link stops verifying, rerun the command and use the new URL it opens or prints.

For both browser-opened and --no-browser authorization flows, pass --timeout-ms 300000 when passkey approval may take longer than the default 120 seconds.

Authorization commands that use --no-browser are interactive waiting processes. Do not choose them just to monitor auth; use normal browser-opened flows first. If --no-browser is necessary, make sure your execution tool will stream stdout/stderr immediately and keep the session open. Capture the printed URL, show it to the user, and continue monitoring until the command completes, times out, or the user asks you to stop. If you cannot monitor live output, do not start the auth flow; tell the user the exact command to run locally instead.

Use login only to connect a wallet profile when none exists. If the CLI reports Wallet already connected to ..., do not rerun login. Use mega moss create-key to add a delegated key to the existing profile, or mega moss logout only when the user explicitly wants this CLI install to forget the local wallet profile.

If create-key fails because the authorized wallet account does not match the local profile, run mega moss whoami, then ask the user to switch the browser wallet/profile to that account. mega moss logout deletes the local profile and delegated private key material; run it only after the user explicitly approves reconnecting this CLI to a different wallet.

Login defaults to mainnet, https://account.megaeth.com, https://wallet-api.megaeth.com, and https://mainnet.megaeth.com/relay. Use --wallet-url, --wallet-api-url, or --relay-url only when deliberately targeting non-canonical endpoints. Use --network testnet for the wallet testnet profile and chain config.

Create-key defaults keep the approval simple: one-week expiry, a 100 USDM workflow spend cap, and explicit 1 USDM relay-fee metadata. The agent must provide call scope with --allow-call <target:signature>, copy a known-good key with --from, or pass a complete --permissions ./permissions.json file. Do not create workflow keys with implicit broad call authority. Use the narrowest call and spend scope that covers the requested workflow.

Use mega moss create-key --spend-limit <token_address>:<amount>:<period> --allow-call ... to add explicit spend rows. Token must be a 20-byte address; use 0x0000000000000000000000000000000000000000 for native ETH. Amount is the human token amount, and period is minute, hour, day, week, month, or year. Repeat --spend-limit for multiple spend rows. Custom permission files must include a non-empty permissions.calls array. Never omit permissions.calls; omitted calls have produced keys that the relay rejects for writes. Each call entry must include both to and signature. Read references/permissions.md before building custom --permissions files, debugging permission schema errors, or planning nontrivial protocol writes. Validate permission shape before running auth commands. Do not use mega moss create-key as a validator for known invalid permission requests. For native ETH transfers, use a native ETH spend row and the no-calldata selector 0xe0e0e0e0 for the recipient target, for example --allow-call '<recipient_address>:0xe0e0e0e0'. Never use the reserved wildcard address 0x3232323232323232323232323232323232323232 or selector 0x32323232.

Use --fee-token <symbol> and optional --fee-limit <amount> on create-key to request explicit delegated-key relay-fee metadata. --fee-limit is a human amount in the selected fee token, defaulting to 1. This does not create a workflow spend row; add explicit --spend-limit rows for workflow token/native movement. If either fee option is present and no --spend-limit is supplied, the CLI requests no workflow spend rows.

Relay fees use delegated-key fee metadata plus relay/account enforcement, while workflow token/native movement uses permissions.spend. Future execute and transfer calls default to the authorizedKey.feeToken returned by wallet approval. The Gas Token shown during approval pays the approval transaction itself and should not be treated as a mutation to the requested key scope.

Inspect The Active Wallet

mega moss whoami --json
mega moss list --json
mega moss permissions 0xKEY_OR_ACCESS_ADDRESS --json

Use these before writes to verify the account, delegated access address, expiry, approved permission limits, and current on-chain spend remaining. If you only have a shortened key id from plain text output, run mega moss list --json and copy the full accessAddress into mega moss permissions. In permissions --json, treat authorizedKey.permissions.spend as the stored request and spendInfos[].remaining as the live execution capacity. spendInfos is Porto/account spend accounting, so it can include relay fee-token allowance even when authorizedKey.permissions.spend is empty.

Execute Writes

mega moss execute \
  --to 0x1234567890abcdef1234567890abcdef12345678 \
  --data 0x \
  --value 0

For multiple writes, pass --calls ./calls.json. Pass --key 0xKEY_OR_ACCESS_ADDRESS only when the user has approved using a non-default stored key. Confirm that the requested operation fits the approved delegated-key permissions before executing.

When hand-writing raw calldata, verify the function selector first with an ABI encoder or cast sig; mismatched selectors cause wrong calls. For --allow-call and permission-file call scopes, prefer canonical human-readable function signatures. Use raw selectors only when necessary; use 0xe0e0e0e0 specifically for native ETH no-calldata transfer scopes and never use wildcard/sentinel selectors such as 0x32323232.

ERC20 approvals must be bundled. On the MegaETH relay, a standalone approve is reset at end-of-transaction. Always include approve and its consuming call in the same --calls array.

Spend permission is not call permission. A key with calls: [] or omitted permissions.calls cannot execute relay-backed writes, including native ETH transfers, even when it has spend allowance. Do not request calls: [] and do not omit permissions.calls; use explicit --allow-call <target:signature> scopes or permission-file call entries with both to and signature.

For workflows that move ERC20 value through another contract, the key usually needs both spend permission for the token and call permission for each contract function it invokes, such as ERC20 approve plus the downstream protocol call. ERC20 spend accounting charges the larger of recognized calldata value (transfer, transferFrom, approve, Permit2 approve) and observed wallet balance decrease. Size spend caps for the larger amount in an approve plus protocol-call batch, not the sum.

Common Patterns

ERC20 approve plus protocol call, such as Aave supply or a swap:

[
  {
    "to": "<TOKEN>",
    "data": "0x<approve(spender,amount) calldata>",
    "value": "0"
  },
  {
    "to": "<PROTOCOL>",
    "data": "0x<supply/swap/deposit calldata>",
    "value": "0"
  }
]

Use one mega moss execute --calls ./calls.json command for the array above. Do not split approval and consumption across two execute calls.

Read State

mega moss call \
  --to 0x1234567890abcdef1234567890abcdef12345678 \
  --data 0x

call is read-only and should be the default for inspection. If --from is omitted, the CLI uses the logged-in wallet account when a local profile exists. Pass --from 0x... only when a different simulation address is needed.

Manage Delegated Keys

mega moss list --json
mega moss list --show-inactive --json
mega moss permissions 0xKEY_OR_ACCESS_ADDRESS --json
mega moss switch 0xKEY_OR_ACCESS_ADDRESS
mega moss create-key \
  --allow-call '0xfafddbb3fc7688494971a79cc65dca3ef82079e7:transfer(address,uint256)' \
  --label "usdm-transfer"
mega moss create-key \
  --spend-limit 0xfafddbb3fc7688494971a79cc65dca3ef82079e7:25:week \
  --allow-call '0xfafddbb3fc7688494971a79cc65dca3ef82079e7:transfer(address,uint256)' \
  --label "agent"
mega moss label 0xKEY_OR_ACCESS_ADDRESS "agent"
mega moss revoke 0xKEY_OR_ACCESS_ADDRESS
mega moss revoke 0xKEY_OR_ACCESS_ADDRESS --fee-token USDm

Use list to inspect local keys. Revoked and expired keys are hidden unless --show-inactive is present. Use permissions to inspect the exact approved scope and remaining on-chain spend before a write. Plain-text output separates the stored approved scope from live on-chain spend remaining. When operating on testnet, pass --network testnet consistently on login, create-key, inspection, writes, revoke, fund, and logout commands.

Use create-key when no existing key has the requested scope; it opens the browser/passkey approval flow and requires explicit call scope unless using --from or --permissions. Add --auth-flow device only when the user must approve from a separate browser/device. Use revoke to revoke a key on-chain; the CLI keeps an inactive audit record but removes local private key material. Revoke defaults to the key's stored fee token. On revoke, --fee-token selects the relay payment token for that revoke transaction.

Update And Uninstall

Release installs check for updates automatically. Use mega moss update --check only when diagnosing version issues, and mega moss update when the user explicitly asks to update immediately.

Do not uninstall unless the user explicitly asks. To remove installed CLI files only:

~/.mega/wallet-cli/current/scripts/uninstall.sh

To remove installed CLI files plus local wallet profiles and delegated private key material:

~/.mega/wallet-cli/current/scripts/uninstall.sh --config

Uninstalling or logging out does not revoke on-chain delegated keys; use mega moss revoke <key> for on-chain revocation.

Custom Permission Files

For the full permission schema and examples, read references/permissions.md.

Transfer Funds

Native ETH:

mega moss create-key \
  --spend-limit 0x0000000000000000000000000000000000000000:0.1:week \
  --allow-call '0xabcdefabcdefabcdefabcdefabcdefabcdefabcd:0xe0e0e0e0'
mega moss transfer --to 0xabcdefabcdefabcdefabcdefabcdefabcdefabcd --amount 0.1

ERC20:

mega moss transfer \
  --token 0x1234567890abcdef1234567890abcdef12345678 \
  --to 0xabcdefabcdefabcdefabcdefabcdefabcdefabcd \
  --amount 100

transfer is a wrapper over execute; it is still a write operation. For ERC20s, the CLI reads token decimals from RPC unless --decimals is provided. Pass --key 0xKEY_OR_ACCESS_ADDRESS only when the user has approved using a specific non-default delegated key.

Fund The Wallet

mega moss fund
mega moss fund --no-open --json

fund opens or prints the wallet deposit URL for the active account. It does not transfer funds by itself.

Debug

mega moss debug --json
mega moss debug --skip-chain --json

Use debug to inspect profile path/mode, account, delegated key expiry, native balance, and relay key status. Do not print or copy profile files.

Logout

mega moss logout

Logout deletes the local wallet profile, including locally stored delegated private key material and key-selection metadata. It does not revoke delegated keys on-chain. Use mega moss revoke <key> when the user wants on-chain revocation; use logout only when the user explicitly wants this CLI install to forget the wallet locally.