[BUG] [deepseek-web] 502 Error: DeepSeek error: onmessage is not defined

[xspylol]

The Bug

When trying to use the DeepSeek Web Cookie Provider with a valid user token, the model fails to stream responses and returns a 502 error.

The console/dashboard displays the following error:
[deepseek-web/deepseek-v4-pro] [502]: DeepSeek error: onmessage is not defined (reset after 3s)

The Steps that i made

1. Open the OmniRoute Dashboard (http://localhost:20128).
2. Go to Providers and configure the DeepSeek Web Cookie provider with a valid user token.
3. Test or call the model deepseek-web/deepseek-v4-pro (via the dashboard or an external CLI like Kilo Code).
4. Observe the 502 error in the UI/terminal logs.

Expected Behavior

The local proxy should successfully capture the stream from DeepSeek's web endpoint and return the completed response to the client.

If DeepSeek recently updated their web client's stream structure, the parser is likely failing to bind the message listener correctly.

[diegosouzapw]

Hey @xspylol! Thanks for the very specific report — this is a real bug. I traced it to open-sse/lib/deepseek-pow-solver.cjs, the bundled PoW solver extracted from DeepSeek's web frontend.

The file is a Web Worker bundle. At the end of the body it does a bare onmessage = t => {...} assignment, which works inside a Worker (where onmessage is a built-in writable). The bundle starts with "use strict";, so when Node require()s it in the main process (not a Worker), strict mode rejects the assignment to an undeclared global with ReferenceError: onmessage is not defined — exactly what you are seeing. We require it from open-sse/lib/deepseek-pow.ts:113 to use the U keccak class as a JS fallback when the WASM solver is not available.

I have opened issue #2724 to track the fix (probably by stripping the worker-only block from the bundle at extract time so it loads cleanly under CJS). The model itself works — the 502 is only raised because we throw on load before reaching the fetch.

As a workaround until the patch ships, you can try deepseek-v4-flash instead — if the WASM solver loads first on your machine, the JS fallback will not be triggered. Will update here once #2724 lands.

[xspylol]

This is amazing, thank you

[diegosouzapw]

Glad it helps, @xspylol! I'll keep #2724 updated as soon as the strict-mode patch lands and ping you here so you can re-test. Appreciate the report -- specific repro like yours is what made the root cause obvious in 5 minutes.