shield-swap-sdk 0.2.0

Python SDK for the shield swap AMM Dex on Aleo

shield-swap-sdk

Typed Python client for the shield_swap AMM on Aleo. Sits on top of the Aleo Python SDK's facade (aleo.Aleo): signer, record provider, proving configuration, and network all come from the client you bind — this package adds the DEX verbs, the typed results, and the off-chain DEX API, nothing else.

from aleo import Aleo
from aleo_shield_swap import ShieldSwap

aleo = Aleo(Aleo.HTTPProvider("https://api.provable.com"))
aleo.default_account = account
dex = ShieldSwap(aleo)

pools = dex.api.get_pools()                      # requires a live DEX API
handle = dex.swap(pool_key=pools[0].key,
                  token_in_id=pools[0].token0,
                  amount_in=10**9).delegate()    # broadcasts; spends funds
out = dex.claim_swap_output(handle).delegate()   # broadcasts; spends funds

Install

pip install -e shield-swap-sdk                 # from the repo root
pip install -e "shield-swap-sdk[async]"        # + AsyncShieldSwap (httpx)
pip install -e "shield-swap-sdk[mcp]"          # + the MCP server

Requires aleo-sdk>=0.2 (this repo's SDK; imports as aleo) and Python 3.10+.

How calls work

Every read returns a value immediately. Every write returns a prepared DexCall — nothing touches the network until you invoke a terminal verb:

call = dex.swap(pool_key=key, token_in_id=token, amount_in=10**9)

call.simulate()             # runs locally; no broadcast, no fee
call.transact(account)      # proves locally, broadcasts, pays the fee
call.delegate(account)      # proves via the delegated proving service

transact and delegate return the verb's typed result (a SwapHandle, MintResult, ClaimResult, …) built from the transaction's root-transition outputs — not a bare transaction id. Local proving downloads SNARK parameters on first use and takes minutes for the larger entrypoints; delegate is the practical path and requires DPS credentials on the provider (api_key=, network_client.consumer_id).

Chain reads and writes live directly on ShieldSwap; the off-chain DEX API is namespaced under .api, so a call site always shows whether a value came from the chain or the service.

The verb surface

Chain reads (node REST API):

Verb	Returns
get_pool(pool_key)	The pool struct from the pools mapping.
get_slot(pool_key)	SlotView — current tick, sqrt price, liquidity, spacing.
get_swap_output(swap_id)	The finalized swap outcome; raises SwapOutputNotFinalizedError until the finalize lands (and again after the claim consumes it).
is_pool_initialized(pool_key)	Whether the pool exists on chain.
get_private_balances(programs)	Summed unspent record amounts per token program (needs a registered record provider).
get_balances()	Public + private balances in one shape.
derive_pool_key(token0, token1, fee) / derive_tick_key(pool_key, tick)	Mapping keys derived locally — no network.

Writes (each returns a DexCall):

Verb	What it does
swap(...)	Phase one of the two-transaction private swap: locks the input record against a blinded identity. Returns a SwapHandle — persist it if the process might die before the claim.
claim_swap_output(handle)	Phase two: claims the finalized output as a private record.
create_pool(...)	Initializes a pool for a token pair + fee tier.
mint(...)	Opens a position in a tick range; returns a MintResult with the position's token id.
increase_liquidity(...) / decrease_liquidity(...)	Resizes a position (spends the position NFT record and returns a fresh one).
collect(...)	Pays out tokens_owed as private records.
burn(...)	Closes an emptied position and removes it from the positions mapping.

Quote before you swap: pass expected_out from dex.api.get_route(...) — without it a spot estimate is used, which ignores fees and price impact. Amounts are u128 base units of the token; fees are microcredits.

DEX API (dex.api, standalone as ApiClient): get_pools, get_tokens, get_route, get_swap, get_ohlcv, get_public_balances. Route quoting, OHLCV, and balances are auth-gated — call api.authenticate(address, sign) once (challenge/verify by signature, no funds required); some deployments additionally gate them behind an invite code.

Privacy

The swap flow never puts your address on chain next to the output. swap derives a single-use blinded identity from the signer's view key (derive_blinding_factor / derive_blinded_address are exported for verification against the TS SDK's vectors); the claim proves knowledge of the blinding factor instead of revealing the owner.

Two conveniences trade secret material for service:

• delegate sends the transaction authorization to the proving service — it can see the transaction's contents (not your private key). Prove locally with transact if that is unacceptable.
• The hosted record scanner behind get_private_balances / aleo.records.register shares the account's view key with the scanning service, which can then see everything the account owns. Self-host the scanner if that is unacceptable.

Async

AsyncShieldSwap / AsyncApiClient mirror the sync surface verb-for-verb on aleo.AsyncAleo (install the [async] extra):

from aleo_shield_swap import AsyncShieldSwap

dex = AsyncShieldSwap(async_aleo)
handle = await (await dex.swap(pool_key=key, token_in_id=token,
                               amount_in=10**9)).delegate()

Agent tools and MCP

shield_swap_tools() returns JSON-schema tool definitions for the whole verb surface; dispatch_tool(dex, name, args) executes one. For MCP hosts, the [mcp] extra ships a stdio server over the same definitions:

ALEO_PRIVATE_KEY=APrivateKey1... python -m aleo_shield_swap.mcp

Omit ALEO_PRIVATE_KEY for a read-only server. See the module docstring for the full environment (ALEO_ENDPOINT, ALEO_NETWORK, DPS credentials).

Generated bindings

The contract surface is pinned, not hand-written: codegen/ holds the deployed program source, its ABI, and the DEX API's OpenAPI document. _generated.py (program structs + entrypoints via aleo.codegen) and _api_models.py (API response models) are built from those pins. When the deployed contract or API drifts, rerun codegen/regen-abi.sh / codegen/regen-openapi.sh and reconcile.

Tests

python -m pytest                        # hermetic tier — no network
python -m pytest -m live               # read-only against the REAL testnet + DEX API
python -m pytest -m "live and slow"    # spends real testnet funds (DPS proving)
ALEO_DEVNODE_UNPROVEN=1 \
python -m pytest -m devnode            # full AMM lifecycle on a local aleo-devnode

The devnode tier deploys the vendored shield_swap_v3.aleo stack and drives pool creation, liquidity, swaps, and burn end-to-end, hermetically. It needs the aleo-devnode binary (ALEO_DEVNODE_BIN or on PATH) and skips otherwise. Deployments are proofless (dummy verifying keys — the devnode skips certificate verification); ALEO_DEVNODE_UNPROVEN=1 extends that to executions and is the fast path (~5 minutes). Without it, executions are fully proven locally: expect SNARK parameter downloads and key synthesis on first use.