trigger_phrase regex rejects valid mentions preceded by non-whitespace chars like ( or "

[thierrypdamiba]

Bug

The trigger phrase regex in src/github/validation/trigger.ts requires the trigger phrase to be preceded by either start-of-string or whitespace:

const regex = new RegExp(
  `(^|\\s)${escapeRegExp(triggerPhrase)}([\\s.,!?;:]|$)`,
);

The leading boundary (^|\\s) is too restrictive. Common patterns where users naturally write the trigger phrase after non-whitespace characters silently fail to trigger.

Reproduction

With default trigger_phrase: "@claude":

Comment	Triggers?	Expected?
@claude help	yes	yes
hey @claude help	yes	yes
(@claude) can you check?	no	yes
"@claude can you check?"	no	yes
>@claude can you check?	no	yes
cc:@claude	no	yes

The workflow if condition (GitHub's contains()) is case-insensitive and passes all these cases, so the workflow runs. But the action's internal trigger check rejects them silently, logging "No trigger found, skipping remaining steps" with exit code 0.

Environment

• anthropics/claude-code-action@v1 (latest as of Feb 13, 2026)
• claude_code_oauth_token auth
• Tested on both issue_comment and pull_request event triggers

Actual logs

No trigger was met for @claude
Trigger result: false
No trigger found, skipping remaining steps

Suggested fix

Replace (^|\\s) with a negative lookbehind for word characters (to still prevent matching inside email addresses like user@claude.com):

const regex = new RegExp(
  `(?<=^|[^a-zA-Z0-9_])${escapeRegExp(triggerPhrase)}([\\s.,!?;:]|$)`,
  "i",  // also fix #910 while we're here
);

Or more conservatively, expand the leading boundary to include common punctuation:

const regex = new RegExp(
  `(^|[\\s(>"'/])${escapeRegExp(triggerPhrase)}([\\s.,!?;:)"']|$)`,
  "i",
);

Related

• trigger_phrase matching is case-sensitive, should be case-insensitive #910 (case sensitivity, different issue but same regex)
• Trigger phrase regex should be case-insensitive and support Unicode word boundaries #923 (Unicode trailing boundary, closed as dup of trigger_phrase matching is case-sensitive, should be case-insensitive #910)