[Binance] Nautilus rejects a new '测试' symbol on Binance Futures testnet

[siman]

BinanceFuturesInstrumentProvider fails when loading all instruments from testnet.

Error:

[INFO] BACKTESTER-001.BinanceFuturesInstrumentProvider: Loading all instruments...

thread '<unnamed>' panicked at crates/model/src/types/currency.rs:102:74:
Condition failed: invalid string for 'code' contained a non-ASCII char, was '测试'
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
fish: Job 1, 'python scripts/nautilus/run_bac…

What happened?

Looks like somebody added a new symbol 测试 (non-ASCII chars) to testnet of Binance Futures. And now Rust code fails when tries to parse the list of available symbols.

[siman]

Now I cannot run backtests with BinanceFuturesInstrumentProvider. Any workarounds for this issue?

[woung717]

I'm experiencing the same issue with my Binance testnet system. It seems Binance will be adding support to Chinese characters to the symbols. (https://developers.binance.com/docs/derivatives/change-log#2025-10-09) The instrument that includes Chinese characters is only exist on the testnet for now. https://demo.binance.com/en/futures/%E6%B5%8B%E8%AF%95USDT

Although it has not yet been added to the mainnet, the Rust-side should supported non-ASCII values since they announced it.

@cjdsellers Could you check this out? Thanks!

Edit: It now seems to have disappeared from the testnet. However, the API response still includes this instrument.
Edit 2: It has also disappeared from the API response.

[woung717]

This is a different issue, but it is related (the error occurred in L207).

nautilus_trader/nautilus_trader/adapters/binance/futures/execution.py

Lines 204 to 210 in a6f593a

	account: MarginAccount = self.get_account()
	position_risks = await self._futures_http_account.query_futures_position_risk()
	for position in position_risks:
	instrument_id: InstrumentId = self._get_cached_instrument_id(position.symbol)
	leverage = Decimal(position.leverage)
	account.set_leverage(instrument_id, leverage)
	self._log.debug(f"Set leverage {position.symbol} {leverage}X")

The intended behaviour seems to be fetching the currently open position and synchronising it to the local MarginAccount "leverage" state (if I understand right). However, for some reason, the L205 API returns a response for every symbol that exists on Binance.

To fetch only open positions, the v3 API (https://developers.binance.com/docs/derivatives/usds-margined-futures/trade/rest-api/Position-Information-V3) needs to be called (it seems the v2 API is currently being called; and will be deprecated later.).

[cjdsellers]

@siman thanks for reporting the issue. I will consider how best to deal with this.

@woung717 thanks for the report. Any chance you could open a new issue for that one?

[cjdsellers]

Hi @siman

Thanks again for taking the time to report this.

The ASCII validation for Symbol strings has now been relaxed to UTF-8, which will resolve this issue. The string still needs to have semantic meaning, so I don't think we're losing much from this slightly looser spec. All other identifiers retain the ASCII requirement f5c79d0.

Closing this for now as fixed, but let me know if there are any further issues!

Follow ups

One follow up here is that I'm not sure if the Chinese symbol will be correctly handled on the way out to Binance. Our URL encoding may work correctly out of the box, or there might be another tweak needed.

References

• https://developers.binance.com/docs/derivatives/change-log#2025-10-09
• https://financefeeds.com/binance-futures-api-adds-support-for-chinese-trading-symbols/

[cjdsellers]

I've just noted this crash on the Binance Futures testnet and will provide a fix shortly:

thread '<unnamed>' panicked at crates/model/src/types/currency.rs:102:74:
Condition failed: invalid string for 'code' contained a non-ASCII char, was '测试测试'
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[cjdsellers]

Turns out this was actually a Currency code (I missed this in the original stack trace).

Now fixed 13291fe.