openclaw - 💡(How to fix) Fix [Bug] Discord REST final-reply and slash-command failures after undici v7 → v8 bump (2026.4.5) [1 comments, 1 participants]

Environment

• OpenClaw version: 2026.4.5 (broken) / 2026.4.2 (working)
• Node.js: v25.9.0
• OS: macOS (Apple Silicon)
• Proxy: HTTP proxy configured via channels.discord.proxy + proxy-preload.cjs (--require injected in LaunchAgent plist)

Description

After upgrading from 2026.4.2 to 2026.4.5, all Discord REST deliveries start failing:

1. Agent replies disappear — streaming/partial content shows briefly, then the final reply edit fails and the message vanishes from Discord.
2. Slash commands hang — /status, /new, /reset never return a response. Discord shows "application did not respond."

The root cause is the undici ^7.24.6 → ^8.0.1 major version bump between these two releases.

Error logs

Content-Type header rejected by Discord API (42 occurrences in one day):

[discord] final reply failed: Error: {"_misc": ["Expected \"Content-Type\" header to be one of
  {'application/json', 'application/x-www-form-urlencoded', 'multipart/form-data'}."]}
    at ProxyRequestClientCompat.executeRequest (…/dist/send-DezGS_D4.js:567:27)
    at ProxyRequestClientCompat.processQueue (…/dist/send-DezGS_D4.js:578:21)

Slash commands — double acknowledgment + timeout:

DiscordError: Interaction has already been acknowledged.
  status: 400, discordCode: 40060

[EventQueue] Slow listener detected: InteractionEventListener took 37037ms for event INTERACTION_CREATE

[discord] slash final reply failed: Error: {"_misc": ["Expected \"Content-Type\" header …"]}

All errors started on the same day as the 4.5 upgrade. Before the upgrade, the only Discord delivery failures were TypeError: fetch failed (network-level), never Content-Type validation errors.

Root cause analysis

The behavioral difference between undici v7 and v8 is visible in the proxy-preload.cjs startup log:

In undici v8, EnvHttpProxyAgent locks the global dispatcher. This interferes with ProxyRequestClientCompat.executeRequest() in send-DezGS_D4.js, which constructs a Headers object, sets Content-Type: application/json (line 530), and calls fetch() with the headers. When the global dispatcher is locked, the Content-Type header is dropped or not forwarded to the Discord API.

Verification steps performed:

1. Proxy itself is not the issue — curl --proxy <proxy> -X PATCH -H "Content-Type: application/json" -d '{}' https://discord.com/api/v10/channels/0/messages/0 returns HTTP 401 (expected), not Content-Type error.
2. undici ProxyAgent works in isolation — Direct test with OpenClaw's bundled undici v8 ProxyAgent + explicit Content-Type header through the same proxy returns HTTP 401 correctly. The issue only manifests when EnvHttpProxyAgent has locked the global dispatcher.
3. Downgrade confirms — Reverting to 2026.4.2 (undici v7) immediately eliminates all Content-Type errors and restores normal Discord message delivery and slash command handling.

How to reproduce

1. Configure an HTTP proxy (e.g., Clash, V2Ray) on 127.0.0.1:<port>
2. Inject proxy-preload.cjs via --require in the gateway launch args (or set HTTP_PROXY/HTTPS_PROXY env vars)
3. Configure a Discord channel with channels.discord.proxy pointing to the same proxy
4. Start the gateway on version 2026.4.5
5. Send a message in Discord → agent streams a partial reply, then the final reply disappears
6. Run any slash command (/status, /new, /reset) → command hangs indefinitely

Expected: Messages delivered, slash commands respond. Actual: Final reply fails with Content-Type error; slash commands timeout.

Workaround

Downgrade to 2026.4.2:

npm install -g [email protected]

The only config incompatibility is plugins.entries.memory-core.config.dreaming (added in 4.5, not recognized by 4.2) — remove it or set the entry to {}.

Additional context

This is likely the same underlying undici v8 regression as:

• #61448 — per-request dispatcher incompatible with built-in fetch
• #61937 — FormData drops fields when dispatcher is present
• #62181 — globalThis.fetch does not honor proxy env vars

The Discord REST path is particularly affected because:

• proxy-preload.cjs sets up a global EnvHttpProxyAgent (locks dispatcher in v8)
• The Discord channel config also creates a per-channel ProxyAgent via makeProxyFetch()
• ProxyRequestClientCompat uses this.customFetch ?? globalThis.fetch — when the global dispatcher is locked, the per-request headers constructed in executeRequest() are not properly forwarded

A potential fix could be to either:

1. Pin undici to v7 until the dispatcher-locking behavior is resolved upstream in undici
2. Avoid using EnvHttpProxyAgent in proxy-preload and instead use per-request ProxyAgent without global dispatcher locking
3. Ensure ProxyRequestClientCompat explicitly passes headers in a way that survives dispatcher locking