/wallet-mcp

title: "Wallet MCP Skill"
description: "Wallet MCP — gives your AI assistant access to a Coinbase Wallet Account via the Wallet MCP server (wallet-mcp.coinbase.com). Wallet, portfolio, sending, swapping, signing, x402 payments, batched contract calls, and transaction history across Base, Ethereum, Arbitrum, Optimism, Polygon, BNB Chain, Avalanche, and Robinhood Chain."
name: wallet-mcp
version: 0.1.0

Wallet MCP

> [!IMPORTANT] > ## Run onboarding at the start of every conversation that touches Wallet MCP > > Including conversations that jump straight to a plugin topic. Onboarding is short — see below.

Detection

The Wallet MCP exposes its tools to the harness when connected. If no Wallet MCP tool is callable, the MCP server is not installed: direct the user to https://docs.cdp.coinbase.com/ai-agents/coinbase-for-agents/wallet-mcp#quickstart (or load [references/install.md](references/install.md) for app-specific steps) and stop.

If Wallet MCP tools are available, load [references/tone.md](references/tone.md) — its rules apply for the entire conversation — then continue to Onboarding. If — and only if — sibling files aren't readable (e.g. you were handed just this `SKILL.md` body and have no local filesystem access to the skill directory), fetch the same relative path from `https://docs.cdp.coinbase.com/coinbase-for-agents/wallet-mcp/references/tone.md` using the `web_request` tool from Wallet MCP. The same fallback applies to every other reference and plugin link in this file (see "Loading referenced files" below).

Onboarding

Keep it short. Do this once per session, before doing real work:

1. **Briefly mention what's available** — one or two sentences. The user has a Coinbase Wallet Account and can do things like check balances, send and swap tokens, sign messages, make x402 payments, and batch contract calls on Base (the default chain) and other supported chains, and (if installed) use third-party plugins for DeFi, swaps, and other onchain actions. Do not enumerate every tool — the agent discovers tools and plugins directly from the MCP.

2. **Show this disclaimer verbatim** before proceeding:

> By using the Base MCP, you agree to the [Base Account and Base App Terms of Service](https://wallet.coinbase.com/terms-of-service). Base MCP provides access to plugins that are built by third parties, not Base. Base doesn't operate, endorse, or audit them, and isn't responsible for the protocols you interact with. Transactions are irreversible — always review before approving.

3. **Wallet address and balance are optional** — only fetch and display them when the user asks, or when a pending operation actually needs the address (e.g., a write call, a position lookup). Don't volunteer a wallet dump up front.

Supported chains

Wallet MCP tools take a `chain` parameter. **Base is the default chain** — use it unless the user asks for another chain or a plugin requires one. Use these exact chain names:

| Chain | `chain` value | |-------|---------------| | Base (default) | `base` | | Ethereum | `ethereum` | | Arbitrum | `arbitrum` | | Optimism | `optimism` | | Polygon | `polygon` | | BNB Chain | `bsc` | | Avalanche | `avalanche` | | Robinhood Chain | `robinhood-chain` | | Base Sepolia (testnet) | `base-sepolia` |

Not every tool covers every chain: x402 payments run on Base and Base Sepolia only, and `swap` is mainnet-only. The tool descriptions exposed by the MCP remain the source of truth for the current set and per-tool limits. Individual plugins may support only a subset of these chains — check the plugin's notice before acting.

Tools

The Wallet MCP advertises its own tool catalog to the harness. Read the tool descriptions exposed by the MCP — they are the source of truth and may change over time. Do not assume a fixed list; do not preload a tool catalog from this skill.

Two patterns deserve their own references because they span multiple tools:

| Topic | Reference | |-------|-----------| | Approval flow (for any write tool that returns an approval URL) | [references/approval-mode.md](references/approval-mode.md) | | Batched contract calls (EIP-5792) | [references/batch-calls.md](references/batch-calls.md) | | Custom / non-native plugins and the `web_request` allowlist | [references/custom-plugins.md](references/custom-plugins.md) | | Platform install steps | [references/install.md](references/install.md) | | Tone and language rules | [references/tone.md](references/tone.md) |

Loading referenced files

• **Default — local.** Read each `references/…` or `plugins/…` link from the same directory as this `SKILL.md` (filesystem read, e.g. `Read`/`cat`). This is the canonical source — always try this first.
• **Fallback — web (only when local read fails).** If — and only if — the local file is genuinely unreadable (e.g. you were handed `SKILL.md` as a pasted body with no skill directory on disk, or the filesystem read errors), then fetch the same relative path from `https://docs.cdp.coinbase.com/coinbase-for-agents/wallet-mcp/<path>` (replace `<path>` with the relative link, e.g. `references/tone.md`, `plugins/morpho.md`). Use the `web_request` tool from Wallet MCP for this fetch — that is the required mechanism on every surface, including ones with a built-in web/fetch tool. Do not skip this fallback and do not try to operate from memory or guesses — if the local read fails, you must `web_request` the file before acting on its contents.
• **Lazy.** Only load a reference or plugin when the conversation actually needs it. Don't preload the catalog.

Plugins

Plugins extend Wallet MCP with third-party functionality (lending, swaps, perps, etc.). Each plugin is a separate third-party service that Base does not operate, endorse, or audit. The available set may change and users might drop additional instructions in the chat or custom plugins that would allow you to use other protocols with the MCP.

Routing rule — name-gated, never auto-routed

Open a plugin *