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NousResearch/hermes-agent

Windows Unicode encoding errors in MCP stdio transport

Cluster 46099 · mcp. Data as of

Nothing open on GitHub. Fix merged in #71014 on 24 Jul 2026. Check it covers your case.

The short answer

0open issues
0open PRs
3items grouped
Known?
Yes. 3 related items grouped here, 1 issue already closed.
Fix event
A fix was merged to main in PR #71014. Check it covers your case. No release data is tracked.
Tracker
The maintainers' tracker marks this resolved, deciding PR #71014. That is separate from the fix event.
Still open
Nothing open on GitHub.

A bug where MCP stdio transport uses strict Unicode error handling causes UnicodeDecodeError on Windows, with fixes applying a more permissive encoding error handler across MCP and related file I/O paths.

Open issues0

No open issues.

Open PRs0

No open pull requests.

Fixes on record

Merged to main. A stamp counts the issues a fix is linked to.

  • #71014 fix(windows): residual encoding gaps — MCP stdio, gateway update file-I/O, STT/TTS, desktop spawn, bootstrap ver-stub

    merged to main

    files: apps/desktop/electron/backend-env.test.ts, apps/desktop/electron/backend-env.ts, gateway/dead_targets.py, gateway/delivery.py, gateway/platforms/qqbot/adapter.py, gateway/run.py, gateway/slash_commands.py, gateway/status.py, hermes_bootstrap.py, plugins/platforms/discord/adapter.py, plugins/platforms/feishu/adapter.py, plugins/platforms/google_chat/adapter.py, plugins/platforms/google_chat/oauth.py, plugins/platforms/telegram/adapter.py, plugins/platforms/whatsapp/adapter.py, tests/gateway/test_gateway_utf8_encoding.py, tests/test_hermes_bootstrap.py, tests/tools/test_mcp_stdio_encoding_handler.py, tools/mcp_tool.py, tools/transcription_tools.py (+1 more)

1 PR closed without merging

From the close comments: merged via another change 1

  • #46104 fix(mcp): use encoding_error_handler='replace' for stdio transport · merged via another change → #71014
Closed issues · 1
  • Closed#46099[Bug]: MCP client TextReceiveStream uses errors='strict' — fails on Windows with UnicodeDecodeError
How this cluster was grouped
  • Link evidence (structural links throughout): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
  • Pairwise link density 0.67: the share of item pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. 1.00 means every pair is linked.

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At a glance

Subsystem
mcp
Merged PRs
#71014
Closed issues
1
Attempts
1 PR closed without merging
Fix link checked
24 Jul 2026

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