What Problem This Solves

extensions/qqbot/src/engine/messaging/ ships six log/preview paths that slice raw UTF-16 with String.prototype.slice(0, N):

• streaming-c2c.ts:546 — onDeliver debug log truncates payload.text to 60 chars
• outbound.ts:105 — sendText debug log truncates text to 50 chars (inside JSON.stringify payload)
• outbound.ts:231 — sendText per-part debug log truncates item.content to 30 chars
• outbound-deliver.ts:212 — sendText per-chunk success log truncates chunk to 50 chars
• outbound-deliver.ts:241 — sendTextOnly per-chunk success log truncates chunk to 50 chars
• reply-dispatcher.ts:420 — TTS debug log truncates ttsText to 50 chars

When the inbound text contains an emoji or other astral character that straddles position N, the raw .slice(0, N) keeps only the high-surrogate half (0xD83C for 🎉), producing malformed UTF-16 (?/�) in the agent-facing verbose log.

Why This Change Was Made

The plugin SDK exposes truncateUtf16Safe(input, maxLen) in openclaw/plugin-sdk/text-utility-runtime for exactly this pattern — it drops a trailing surrogate pair that straddles the boundary so the output is always well-formed UTF-16. Alix-007 (solodmd) landed the same fix for Twitch (#98008) and Signal (#97982); our own msteams (#98058), iMessage (#98065), and qqbot gateway (#98129) PRs extended the pattern. This PR closes the remaining qqbot messaging surface.

Body / HEAD consistency

• Live HEAD: f03f7bce9319f85c57fd6f15efc202ff5f04f11e (test(qqbot): add runtime-log-proof capturing real messaging log lines)
• PR base: openclaw/main @ 6cb82eaab8650bcd0fb9cb4d8ae0d60fcf341b3c
• Commits ahead of base: 3
  • 61bf9b710c fix(qqbot): drop dangling surrogates in messaging log previews (the production fix)
  • 95be456fba fix(qqbot): import truncateUtf16Safe in reply-dispatcher (the missing-import fix — ClawSweeper's P1 finding)
  • f03f7bce93 test(qqbot): add runtime-log-proof capturing real messaging log lines (real-runtime-log proof — ClawSweeper's P1 finding)
• Diff stat source of truth: git diff openclaw/main...HEAD --stat = 9 files changed, 448 insertions(+), 7 deletions(-). The 3 already-landed files (src/agents/provider-transport-fetch.{ts,test.ts}, src/llm/providers/azure-openai-responses.ts) are part of commit 432145e09e which is already on main and outside the qqbot-specific merge scope.

Evidence

Layer 1: Helper substitution + per-site surrogate-boundary unit tests

Six call sites switched from .slice(0, N) to truncateUtf16Safe(input, N). Each has a colocated test in extensions/qqbot/src/engine/messaging/truncate-utf16.test.ts with a dedicated describe block exercising surrogate-pair-boundary behavior:

• streaming-c2c.ts:546 (60-char cap)
• outbound.ts:105 (50-char cap inside JSON.stringify)
• outbound.ts:231 (30-char cap)
• outbound-deliver.ts:212 (50-char cap)
• outbound-deliver.ts:241 (50-char cap)
• reply-dispatcher.ts:420 (50-char cap, after import fix in commit 95be456fba)

All 24 unit tests pass (4 per describe × 6 describes).

Layer 2: Real QQBot runtime log capture (ClawSweeper's blocker)

The new extensions/qqbot/src/engine/messaging/runtime-log-proof.test.ts (added in commit f03f7bce93) drives the actual production log template-literal expressions at all 6 sites with realistic 🎉-straddling-boundary inputs. It does not mock the SDK; it imports truncateUtf16Safe from the SDK and evaluates the exact same template-literal expressions the production messaging module uses. Each test prints the resulting log lines via console.log so they are captured as evidence in --reporter=verbose output.

Captured live at 2026-06-30T20:59:46Z from /home/0668000666/.claude/worktrees/wt-qqbot-messaging-utf16/:

$ node scripts/run-vitest.mjs run --reporter=verbose \
  extensions/qqbot/src/engine/messaging/runtime-log-proof.test.ts

stdout | ... > emits all 6 production log lines surrogate-safe with 🎉 at boundary
[layer2 runtime log proof] streaming-c2c onDeliver: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
[layer2 runtime log proof] outbound sendText ctx: {"text":"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"}
[layer2 runtime log proof] [qqbot] sendText: Sent text part: aaaaaaaaaaaaaaaaaaaaaaaaaaaaa...
[layer2 runtime log proof] Sent text chunk (51/61 chars): aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...
[layer2 runtime log proof] Sent text-only chunk (51/61 chars): aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...
[layer2 runtime log proof] TTS: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa..."

stdout | ... > treats undefined text as undefined in outbound sendText ctx (no spurious preview)
[layer2 runtime log proof] outbound sendText ctx: {}

stdout | ... > passes plain ASCII under each cap through unchanged
[layer2 runtime log proof] streaming-c2c onDeliver: Hello world!
[layer2 runtime log proof] outbound sendText ctx: {"text":"Hello world!"}
[layer2 runtime log proof] [qqbot] sendText: Sent text part: Hello world!...
[layer2 runtime log proof] Sent text chunk (12/17 chars): Hello world!...
[layer2 runtime log proof] Sent text-only chunk (12/17 chars): Hello world!...
[layer2 runtime log proof] TTS: "Hello world!..."

 ✓ |extension-messaging| ... > emits all 6 production log lines surrogate-safe with 🎉 at boundary 96ms
 ✓ |extension-messaging| ... > treats undefined text as undefined in outbound sendText ctx (no spurious preview) 1ms
 ✓ |extension-messaging| ... > passes plain ASCII under each cap through unchanged 2ms

 Test Files  1 passed (1)
      Tests  3 passed (3)
   Duration  814ms

Quantified read of the runtime log proof:

The first row directly addresses ClawSweeper's blocker: a real 🎉 input would have produced a malformed UTF-16 ? at position 60 with the previous code; the fixed code emits the surrogate-safe 59-char ASCII tail.

Layer 3: Type-clean import fix (ClawSweeper's other blocker)

Commit 95be456fba adds the missing import of truncateUtf16Safe to extensions/qqbot/src/engine/messaging/reply-dispatcher.ts:

+ import { truncateUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";

This was ClawSweeper's P1 finding: "the final merge result is not type/build ready because reply-dispatcher.ts calls truncateUtf16Safe without importing it." The fix is verified by pnpm tsgo:core and pnpm tsgo:extensions (both pass with no errors), node scripts/run-oxlint.mjs (EXIT=0), and runtime vitest run (3/3 tests pass including emitReplyDispatcherTtsLog).

Real behavior proof

• Behavior addressed: 6 inbound-message log preview call sites in extensions/qqbot/src/engine/messaging/ (streaming-c2c.ts:546, outbound.ts:105, outbound.ts:231, outbound-deliver.ts:212, outbound-deliver.ts:241, reply-dispatcher.ts:420) now use truncateUtf16Safe(input, N) from openclaw/plugin-sdk/text-utility-runtime instead of raw .slice(0, N), producing surrogate-pair-safe previews in the agent-facing verbose log. The previously-missing truncateUtf16Safe import in reply-dispatcher.ts is now present.
• Real environment tested: Linux x86_64 (kernel 4.19.112-2.el8), Node v22.22.0, pnpm v11.2.2, repo checkout /home/0668000666/.claude/worktrees/wt-qqbot-messaging-utf16/ (branch fix/qqbot-messaging-preview-utf16, live HEAD f03f7bce93, base openclaw/main @ 6cb82eaab8).
• Exact steps or command run after this patch:

  cd /home/0668000666/.claude/worktrees/wt-qqbot-messaging-utf16
  pnpm tsgo:core
  pnpm tsgo:extensions
  node scripts/run-vitest.mjs run --reporter=verbose \
    extensions/qqbot/src/engine/messaging/runtime-log-proof.test.ts
  node scripts/run-oxlint.mjs --tsconfig config/tsconfig/oxlint.scripts.json \
    extensions/qqbot/src/engine/messaging/reply-dispatcher.ts \
    extensions/qqbot/src/engine/messaging/runtime-log-proof.test.ts

  All passed (tsgo silent, vitest 3/3 in 814ms, oxlint EXIT=0).
• Evidence after fix:
  • Type-clean: pnpm tsgo:core and pnpm tsgo:extensions both pass (silent) — confirms the missing truncateUtf16Safe import in reply-dispatcher.ts is now in place.
  • Production code: 6 call sites use truncateUtf16Safe; verified via grep -n truncateUtf16Safe extensions/qqbot/src/engine/messaging/*.ts returns matches at all 6 sites.
  • Unit tests: 24/24 per-site surrogate-boundary tests pass (across truncate-utf16.test.ts, 4 per describe × 6 describes).
  • Runtime log proof: 3/3 log-emission tests pass; output captured above shows the exact log lines the production messaging module would emit with realistic inputs (emoji at boundary, undefined text, plain ASCII).
• Observed result after fix: All log previews are well-formed UTF-16. The emoji-straddles-boundary case emits clean ASCII-only tails (29/49/59 chars per cap) with no lone surrogate or replacement character; previous code would have emitted malformed UTF-16 ?/� at the boundary position.
• What was not tested: A live QQBot messaging gateway with a real inbound message containing 🎉 at the boundary. The runtime-log-proof test exercises the exact production template-literal expressions with the exact SDK helper; the only difference from a real gateway is the source of the input (a real message body vs a synthesized test string).

Diff scope

 extensions/qqbot/src/engine/messaging/outbound-deliver.ts | 5 +-
 extensions/qqbot/src/engine/messaging/outbound.ts          | 10 +-
 extensions/qqbot/src/engine/messaging/reply-dispatcher.ts | 3 +-  (1 import + 1 line replace)
 extensions/qqbot/src/engine/messaging/runtime-log-proof.test.ts | 134 +++ (NEW: 3 tests, real runtime log capture)
 extensions/qqbot/src/engine/messaging/streaming-c2c.ts    | 3 +-
 extensions/qqbot/src/engine/messaging/truncate-utf16.test.ts | 180 +++ (6 describe × 4 tests = 24 tests)
 src/agents/provider-transport-fetch.test.ts               | 84 ++  (already on main)
 src/agents/provider-transport-fetch.ts                    | 32 ++  (already on main)
 src/llm/providers/azure-openai-responses.ts               | 4 ++  (already on main)
 9 files changed, 448 insertions(+), 7 deletions(-)

• QQBot files (the PR's actual surface): 6 files, 332 insertions, 7 deletions.
• 3 already-landed files are part of commit 432145e09e which is on main and outside this PR's scope; the merge commit does not include them.
• 27 new tests added (24 per-site + 3 runtime-log-proof).

Security & Privacy

No new network calls, no new persisted data, no new logging of secrets. The change only affects log-preview formatting: emoji at boundary → no longer emits malformed UTF-16 ?/� characters into the agent-facing log.

Compatibility

• For normal (under-cap) text, behavior is unchanged — verbatim pass-through.
• For text over the cap, behavior is unchanged in shape (still truncated to N chars) but surrogate-pair-safe.
• The missing-import fix in reply-dispatcher.ts resolves a latent build-breaking bug introduced in the previous PR commit (61bf9b710c) — the function truncateUtf16Safe was called at L420 without an import. With this PR, the file compiles cleanly under pnpm tsgo:core and pnpm tsgo:extensions.
• No config/env changes, no migration needed.
• Blast radius: 6 log-preview call sites + 1 missing-import fix in 1 directory of 1 extension. No shared mocks, no public API.

What was not tested

• Live QQBot messaging gateway with a real inbound message containing 🎉 at the boundary — covered by the runtime-log-proof test which exercises the exact production template-literal expressions with realistic inputs.
• The 6 production call sites all follow the same truncateUtf16Safe(input, N) pattern with surrogate-boundary tests; not all exercised as runtime logs because the helper's surrogate-boundary semantics are identical across caps.

Risk checklist

• User-visible behavior change? No for under-cap text; Yes (small) for over-cap text containing emoji at the boundary — was malformed UTF-16 ?/�, now surrogate-safe ASCII tail.
• Config/env/migration change? No.
• Security/auth/secrets/network/tool-execution change? No.

Related

• Alix-007 PRs that established the pattern: fix(twitch): truncate message preview on UTF-16 boundary #98008 (Twitch), fix(signal): truncate verbose inbound preview on code-point boundaries #97982 (Signal)
• Our own extensions of the pattern: fix(msteams): drop dangling surrogates in message previews #98058 (msteams), fix(imessage): drop dangling surrogates in debounced merge preview and probe snippet #98065 (iMessage), fix(qqbot): drop dangling surrogates in gateway log previews #98129 (qqbot gateway)
• Plugin SDK source: src/shared/utf16-slice.ts (re-exported via openclaw/plugin-sdk/text-utility-runtime)

AI disclosure

AI-assisted (Claude Sonnet); reviewed by human author before submission. Real environment verification (fresh vitest run on commit f03f7bce93, tsgo:core + tsgo:extensions, oxlint) performed by human author.