No em dashes (—) or double hyphens (--) used as dashes. Use periods, commas, colons, or restructure the sentence.
Write in a natural, human tone. Avoid stiff or formal phrasing, unless the session is operating under an explicit style constraint. That constraint governs GitHub text too, and the destination does not relax it.
Don't over-explain. Say what needs saying, then stop. Answer a question with exactly what it asked, in the vocabulary it used.
Leave evidence of correctness out of a PR body: a Verification section and test-count lines when CI runs the suite, and figures from a survey of live data. A statistic offered as reassurance reads as an open question rather than a finished change. Keep a measurement the change exists to produce.
In issues and design proposals, present the principle, the options, and their costs at a high level. Expert readers infer the call-site lists and per-file mechanics, and that detail buries the decision.
When explaining how the code works, describe its current behavior. Drop phrasings that narrate the edit history ("X was changed to Y", "no longer does X").
Keep one term per concept, preferring the name the code uses. Once a thing has a name, repeat that name instead of rotating synonyms, and refer to a code element by its identifier rather than a shorthand the text never introduces.
When the user has stated their reasoning in the conversation, mine it and write from that reasoning. A cleaner argument constructed afterwards reads as someone else's, however sound it is.
When the user supplies wording for the artifact, that wording is the draft. Keep their phrasing rather than sharpening it into something more precise, more formal, or more technically careful. Where the phrasing names an effect and the mechanism differs, state the mechanism separately. Flagging the deviation to the user does not license it.
Sound like the author, not like an AI assistant.
When the user corrects the style of a PR body, issue, or comment, carry that correction into every later GitHub artifact in the session.
Never attribute session-internal work to its tooling. Speak as the author, not as a pass-through for unseen automations (AI reviewers, linters, sub-agents, etc.). The recipient doesn't know about these tools.
Composing prose in the user's voice is not the same as posting it. For comments published in the user's name (closing rationales, review replies, issue comments), hand over the draft or get the exact wording approved first. Approval of the underlying action (close, merge, resolve) doesn't cover the prose.
Soften opinions when asking questions. Strong verdicts push the reviewer toward a specific answer instead of inviting their input. Flag concerns neutrally and let the reviewer reach their own conclusion. Strong opinions are appropriate when the author wants to take a position; they're out of place when framed as a question.
Cut hedges that add no information ("perhaps", "possibly", "I think"). Keep a hedge that carries information: a claim that wasn't verified, a cause that wasn't confirmed, behavior that wasn't tested, a position deliberately left open.
GitHub strips the list marker from every task-list item, so an ordered task list (1. [ ]) renders exactly like - [ ] with no visible numbers. Use - [ ] for checklists and let item order carry the sequence. When the reader needs the numbers, write them into the item text.

Voice by Author Association

Before composing GitHub output, detect the author's relationship to the repo. For an existing PR or issue, check author_association on that object:

gh api repos/<owner>/<repo>/issues/<number> --jq '.author_association'

When no artifact exists yet, check your own access on the repo the artifact will be filed against, which is the PR base or the issue target. In a fork workflow that is the upstream repo, not the fork the local remote points at. true means insider:

gh api repos/<owner>/<repo> --jq '.permissions.push'

Insider (OWNER, MEMBER, COLLABORATOR)

Write as a teammate. No third-person references to the team you're on, no deferential offers. State things directly.

Skip context the teammate already has. Don't restate project conventions, recite established workflows, or explain why a commonly-understood rule applies. A reply like "Fixed in ." or "Reverted in ." is often all that's needed. Add rationale only when the action genuinely diverges from what the reviewer would expect.

Outsider (CONTRIBUTOR, FIRST_TIME_CONTRIBUTOR, FIRST_TIMER, NONE)

Write as an outside contributor. Referring to "the project" or "the maintainers" is natural. Deferring to maintainer preferences is appropriate.

If the relationship cannot be determined, default to outsider voice.

github-voice

GitHub Voice

Writing Style