uniswap_prices

MCP server based on FastMCP. Runs over stdio by default, or as a local HTTP service (see Running over HTTP (Docker)). Reads Uniswap V1/V2/V3 reserves directly on-chain via a public, unauthenticated Ethereum RPC endpoint — no API key required.

Scope

This server does exactly one thing: read Uniswap pool reserves straight from the chain.

• Genuinely zero-auth. No API key, no account, no sign-up — not even for the underlying data source. Most "crypto price" MCP servers are thin wrappers around a paid/rate-limited pricing API (CoinGecko, 1inch, etc.) that still needs a key. This one talks directly to a public Ethereum RPC endpoint and reads the pool contracts' own storage — there's no intermediary to authenticate to, and nothing to keep secret.

• Uniswap only, on purpose. It doesn't try to be a universal multi-DEX or multi-chain price server. It knows Uniswap V1/V2/V3 and nothing else. If you need broader coverage, compose it with other narrow, single-purpose MCP servers instead.

Related MCP server: uniswap-pools-mcp

Tools

• get_v1_reserves(token) — ETH/token reserves of a token's Uniswap V1 exchange (V1 pairs are always ETH<->token).

• get_v2_reserves(token_a, token_b) — reserves of a Uniswap V2 pair via getReserves().

• get_v3_reserves(token_a, token_b, fee=None) — on-chain reserves (pool token balances) of Uniswap V3 pool(s); if fee is omitted, all standard fee tiers are checked.

token/token_a/token_b accept either a mainnet ERC20 contract address or a known symbol (ETH, WETH, USDC, USDT, DAI, WBTC).

By default the server talks to https://ethereum-rpc.publicnode.com; override with the UNISWAP_PRICES_RPC_URL env var.

Setup

git clone <this-repo-url>
cd uniswap_prices
conda create -n uniswap_prices python=3.12 -y
conda activate uniswap_prices
pip install -e .

Run

python -m uniswap_prices.server

or, if configured as an entry point in an MCP client:

{
  "command": "python",
  "args": ["-m", "uniswap_prices.server"]
}

Running over HTTP (Docker)

The server can also run as a local HTTP service (streamable-http transport) instead of stdio — useful for MCP clients that connect over HTTP, or for running the server as a standalone daemon.

Without Docker:

UNISWAP_PRICES_TRANSPORT=http UNISWAP_PRICES_HTTP_HOST=127.0.0.1 UNISWAP_PRICES_HTTP_PORT=8000 \
  python -m uniswap_prices.server

The MCP endpoint is then available at http://127.0.0.1:8000/mcp.

With Docker:

docker compose up --build
# or, to bind a different host port (e.g. if 8000 is already taken):
UNISWAP_PRICES_HOST_PORT=8001 docker compose up --build

or plain Docker, picking any free host port yourself:

docker build -t uniswap_prices .
docker run -p 8000:8000 uniswap_prices

Env vars (all optional):

• UNISWAP_PRICES_TRANSPORT — stdio (default) or http.

• UNISWAP_PRICES_HTTP_HOST — bind host for HTTP mode (default 127.0.0.1; the Docker image sets this to 0.0.0.0).

• UNISWAP_PRICES_HTTP_PORT — bind port for HTTP mode (default 8000).

• UNISWAP_PRICES_RPC_URL — override the Ethereum RPC endpoint.

Development

• Tools are defined in src/uniswap_prices/tools/.

• Each tool's logic is kept separate from the @mcp.tool() decorator so it can be unit tested.

• Do not use print() for debugging: it breaks the stdio protocol. Use logging or sys.stderr instead.

Tests

pip install -e ".[dev]"
pytest

License

MIT