[fix] Unauthorized error

[cullenwatson]

Fixes "Unauthorized/Invalid api key" error

---

Note

Serialize the request body with compact JSON when building HMAC signatures to ensure cross-language consistency and prevent auth errors.

• Signing:
  • Use json.dumps(..., separators=(",", ":")) to serialize body in build_hmac_signature, ensuring a canonical HMAC message across languages.

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[starling114]

@cullenwatson Thanks for this fix, I can confirm that it works. Post order doesn't throw unauthenticated errors anymore

[starling114]

@fednerpolymarket @JonathanAmenechi Could you please guys check this PR? It does fixes an issue with post_order throwing Unauthorized/Invalid api key

[felix5572]

same issue. @cullenwatson

and Remember to import json

[noahverner1995]

OH MY GOD THANK YOU SO MUCH FOR THIS WELL NEEDED PR @cullenwatson DEV.

Basically the Python client was doing

# from hmac.py file
if body:
    # old behavior
    message += str(body).replace("'", '"')

So the HMAC was computed over a non-canonical string representation of the body ("{'price': '0.3', 'size': 5}" style), which doesn’t match the canonical JSON used by the Go/TS servers. Result: the server thinks the signature is wrong and replies with:

{"error":"Unauthorized/Invalid api key"}

By changing hmac.py file with these few lines

import json
if body:
    message += json.dumps(body, separators=(",", ":"))

The server gets what it expects

I can confirmed it worked after modifying it. I'm no longer getting this API Exception when placing trades:

[order] PolyApiException: PolyApiException[status_code=401, error_message={'error': 'Unauthorized/Invalid api key'}]

[lightyLi]

Some issue, it works for me. Thanks

[fednerpolymarket]

Going to test this today

[fednerpolymarket]

Thanks we'll get this merged

[cullenwatson]

i wouldnt merge yet actually, trying now and it breaks other orders. interesting..

[fednerpolymarket]

i wouldnt merge yet actually, trying now and it breaks other orders. interesting..

Hey, it'd be great to know which ones broke for you. And alright I'll add some more unit testing to see if I can find your issue