Mainnet: OPUL/ALGO Pool Returning Wrong Quote

[albertshin]

Running the following on mainnet:

ALGO = client.fetch_asset(0)
OPUL = client.fetch_asset(287867876)
pool = client.fetch_pool(OPUL, ALGO)
quote = pool.fetch_fixed_input_swap_quote(ALGO(2500), slippage=0.01)

returns, for example, 2955 as quote.

In reality, this is actually 0.2955, so the quote is actually is off by exactly 10000 for some reason.

[fergalwalsh]

I think the issue here is due to the differing number of decimals per asset.

All amounts and prices in the SDK are expressed in terms of the microunits of the assets. The prices/amounts you see displayed in the Tinyman UI are adjusted according to the defined number of decimals for the asset. All internal calculation on the blockchain and in the SDKs use the microunit integer representation.

When you write ALGO(2500) it means 0.002500 Algo because Algo has 6 decimals.
2500.0 Algo would be ALGO(2500_000_000).

Opul has 10 decimals so 1000 in microunits for example is actually 0.0000001 Opul.

While the display price or ratio between the assets might be 1:0.2955 the actual ratio of their microunits could be 1:2955 due to the difference in the number of decimals.

[albertshin]

Hi, this seems to be an issue in v1.1. I understand @fergalwalsh's comment on differing decimals and "adjust" for this after I get the quote from the pool, but it seems that fetch_fixed_input_swap_quote is assuming that the number of decimals is the same across all units which does not seem to be the expected output for some pools where the input and output have different decimals.

[gokselcoban]

@albertshin, Can you please share an example? It would be great to share an example code with expected and real values.

Sorry, you have already did.

[gokselcoban]

Microunits don't have an decimal place. Microunit should be an integer, so your expectation0.2955 is not valid.

fetch_fixed_input_swap_quote is assuming that the number of decimals

I think, you don't need to consider decimal place in this calculation, since microunits don't have an decimal place.

[albertshin]

I see what you mean. Re-reading Fergal's original reply that everything is expressed in microunits makes more sense now. Thanks!