sponge-mcp

A scaffold for a Sponge MCP server built with dedalus-mcp and DAuth-style credential exchange.

This server follows a DAuth-style credential exchange pattern:

• Credentials are provided by clients at runtime.

• The server declares a Connection with SecretKeys.

• Tool calls dispatch through Dedalus secure connection handles.

Scaffold Scope

• DAuth-compatible API key authentication (SPONGE_API_KEY).

• Configurable Sponge base URL via SPONGE_BASE_URL.

• Read-only wallet inspection tools for the core Sponge wallet API.

• Includes a smoke ping tool for quick MCP handshake validation.

• Keeps the implementation intentionally small so Sponge engineers can extend it.

Related MCP server: Bankless Onchain MCP Server

Setup

1. Create a Sponge API key.

2. Copy env template:

cp .env.example .env

Required:

• SPONGE_API_KEY (provided by the MCP client via DAuth credentials in production flows)

Optional:

• SPONGE_BASE_URL (defaults to https://api.wallet.paysponge.com)

• DEDALUS_AS_URL (defaults to https://as.dedaluslabs.ai)

• HOST (defaults to 127.0.0.1)

• PORT (defaults to 8080)

Run

uv run python src/main.py

Hosted SDK usage

For the current published Dedalus Python SDK, hosted MCP credentials are matched using a slug-derived connection name. For this deploy, use tsion-sponge-mcp when constructing runtime SecretValues:

import os

from dedalus_labs import AsyncDedalus, DedalusRunner
from dedalus_mcp.auth import Connection, SecretKeys, SecretValues

sponge = Connection(
    name="name-of-server", #if name of server is tsion/sponge-mcp use tsion-sponge-mcp
    secrets=SecretKeys(api_key="SPONGE_API_KEY"),
    base_url="https://api.wallet.paysponge.com",
    auth_header_format="Bearer {api_key}",
)
sponge_secrets = SecretValues(sponge, api_key=os.getenv("SPONGE_API_KEY", ""))

client = AsyncDedalus(
    api_key=os.getenv("DEDALUS_API_KEY"),
    as_base_url="https://as.dedaluslabs.ai",
)
runner = DedalusRunner(client)

result = await runner.run(
    input="Use Sponge to get my wallet balances.",
    model="openai/gpt-4.1-mini",
    mcp_servers=["tsion/sponge-mcp"],
    credentials=[sponge_secrets],
)

Tool Surface

• sponge_get_addresses

• sponge_get_balances

• sponge_get_balance

• sponge_get_transaction_history

• sponge_get_transaction_status

• smoke_ping

Notes

• Sponge wallet endpoints are served from https://api.wallet.paysponge.com.

• This scaffold is intentionally wallet-only for now; future admin tools can be layered on once Sponge exposes a stable public REST surface for them.