Why AI Coding Assistants Silently Block Your Vercel Deployments (And How to Fix It)

Every push showed the same thing: a clean local commit, a normal-looking `git push`, no errors, nothing in red. By every signal available in a terminal, the code was live. It wasn't. For a stretch of about three weeks, every single deployment to production had failed silently, and the only reason it surfaced at all was a routine check of the Vercel dashboard that happened to land on the deployments tab instead of the usual overview page.

That gap — between "the push succeeded" and "the site actually updated" — is the whole problem this guide is about. It's caused by something almost nobody checks for, because almost nobody has a reason to suspect it: an AI coding assistant quietly attaching itself to every commit as a co-author, and a hosting platform's collaboration rules reacting to that attachment by refusing to deploy anything at all.

Git has a real, long-standing feature called a commit trailer — a line at the bottom of a commit message in a specific `Key: Value` format that tools can read programmatically. One of the standard trailers is `Co-authored-by: Name <email>`, originally built for legitimate pair-programming: two developers work on the same change, and both get credit on the same commit.

Several popular AI coding tools have adopted this exact mechanism to credit themselves. By default, without being asked, they append a line like `Co-Authored-By: Claude <noreply@anthropic.com>` (Claude Code), `Co-authored-by: Copilot <copilot@github.com>` (GitHub Copilot's Chat and agent modes in VS Code), or `Co-authored-by: Cursor <cursoragent@cursor.com>` (Cursor) to the bottom of every commit message they help generate. Some tools use a different mechanism entirely — Devin adds a similar trailer alongside a "Generated with Devin" line, while Aider instead appends `(aider)` directly to the git author name rather than using a trailer at all — but the practical effect across most of them is the same: the AI ends up recorded as a contributor to the commit, by default, without a prompt asking first.

“A commit trailer built for two humans pair-programming is now, by default, crediting an AI on almost every commit several popular coding tools touch.”

This wouldn't matter much if it stayed inside the commit message. It doesn't. GitHub actively parses `Co-authored-by` trailers and uses them to build the repository's Contributors list — the same sidebar widget that shows everyone who has committed to a project. Once even one commit anywhere in a repository's history carries that trailer, the AI shows up there, listed as a contributor alongside the actual human developer, on a repository that developer may have built entirely alone.

This is computed from the repository's commit history as a whole, not from any single commit in isolation. That detail matters a lot for how this eventually gets fixed, and it's covered in detail further down.

Vercel's Hobby plan — the free tier most solo developers and side projects run on — has a documented restriction: it does not support collaboration on private repositories. Vercel's own documentation states it plainly: "The Hobby Plan does not support collaboration for private repositories... To deploy commits under a Hobby team, the commit author must be the owner of the Hobby team... This is verified by comparing the Login Connections Hobby team's owner with the commit author."

In practice, that check isn't limited to a single commit's author field — it evaluates whether every contributor GitHub recognizes for the project has access to the connected Vercel project. Once an AI tool's co-author trailer gets GitHub to list it as a contributor, Vercel sees a contributor without Vercel access and blocks the deployment, with the exact error: "The deployment was blocked because the commit author did not have contributing access to the project on Vercel. The Hobby Plan does not support collaboration for private repositories."

Every deployment after that point fails the same way, silently, regardless of what the commits actually contain — including commits that don't have the trailer at all, for reasons covered in the next section.

Before changing anything, confirm the diagnosis rather than assuming it. Open your Vercel project's Deployments tab and look at the status column — a run of deployments marked "Blocked" (shown in red or amber, depending on the dashboard theme) going back further than expected is the first sign. Click into any one of them; the deployment detail page shows the exact reason under "Deployment Blocked," and if it matches the wording quoted above, this is confirmed.

On the GitHub side, open the repository's main page and check the "Contributors" panel in the right-hand sidebar. If an entry for the AI tool shows up there — the exact name varies ("claude", "Copilot", "cursor-agent", or similar) — that's the direct cause. You can also confirm it from the command line with `git log --format="%B" | grep -i "co-authored-by"`, which prints every commit message containing that trailer anywhere in your history.

Every AI coding tool that does this has a way to turn it off, and it's worth finding regardless of which fix you use next, since none of the other fixes matter if new co-authored commits keep getting created on top of them.

• Claude Code: add an `attribution` block to `.claude/settings.json` or `.claude/settings.local.json`: `{ "attribution": { "commit": "", "pr": "" } }`. Setting these to empty strings suppresses the trailer entirely on future commits and PR descriptions.
• GitHub Copilot (VS Code): open Settings and turn off `git.addAICoAuthor` (this default is expected to flip to off in a future VS Code release, per Microsoft's own tracking issue, but don't wait on that — set it explicitly now).
• Cursor: Settings → Agent → Attribution (relocated to "Git & PRs → Attribution" in newer versions) has a toggle to disable it. Organizations can force this off account-wide for every member.
• Devin: the CLI configuration file has a setting to omit attribution from generated commits and PRs — check Devin's current configuration documentation for the exact key, since tool settings change over time.
• Aider: pass `--no-attribute-author` and `--no-attribute-committer` to stop it from modifying the git author name; it doesn't add a co-author trailer by default in the first place.

Turning off future attribution stops new damage. It does not undo what's already in the repository's history, and because Vercel's check looks at the project's overall contributor list — not just the tip commit — a single clean commit on top of a dirty history usually isn't enough on its own. From here there are four genuinely different paths, and which one makes sense depends entirely on what you're willing to trade.

Create a new branch containing your current code as a single, brand-new commit with no ancestry connecting it to the old, tainted history — then make that new branch the one your host deploys from. This avoids two things people often assume are required: it does not touch or delete the old branch, and it does not require force-pushing over anything, since it's an entirely new branch pushed normally.

The commands: `git checkout --orphan clean-main` creates a branch with no commit history at all. `git add -A` stages the current file tree. `git commit -m "Clean baseline"` creates a single, solely-authored commit. `git push origin clean-main` pushes it as a new branch — a normal, non-destructive push. From there, change your hosting platform's production branch setting to point at the new branch, and (on GitHub) change the repository's default branch to match, since GitHub's contributor computation is generally tied to whichever branch is marked default.

The real limitation, and one worth knowing before you rely on this alone: the old branch, if left in the repository, may still cause the same repository-wide contributor list to include the AI, since the old history hasn't gone anywhere — it's just no longer the branch being deployed. Whether that continues to block deployments depends on exactly what your hosting platform's check is actually evaluating, which isn't always documented precisely. If the block persists after this step, the old branch needs to actually be deleted from the remote, not just abandoned.

Vercel's restriction is explicitly scoped to private repositories. A public repository on the Hobby plan doesn't hit this collaboration check at all, regardless of how many contributors GitHub lists. This is the fastest fix by a wide margin — a setting flip, no git operations — but it means your source code becomes visible to anyone who looks, permanently, until you make it private again (which would reintroduce the original problem if the old history is still there).

Whether that tradeoff is acceptable depends entirely on what's in the repository. A content-driven site or a tool with no proprietary algorithm loses little by going public. A project where the implementation itself is the competitive advantage is a very different calculation.

Vercel's Pro plan (and equivalent paid tiers on other platforms with similar restrictions) explicitly supports collaboration on private repositories, which removes this restriction entirely regardless of how many contributors are on record. This is the only option on this list that doesn't require any git surgery or a visibility tradeoff — it's a direct fix for the actual constraint causing the block. It costs money on an ongoing basis, which is the whole tradeoff.

The most complete fix is stripping the trailer from every commit that has it, across the entire history, using a tool built for history rewrites like `git filter-repo`, then force-pushing the result over what's currently on the remote. Done correctly, this actually removes the AI from the contributor list rather than working around it.

This is also the riskiest option on this list by a meaningful margin, and it deserves to be treated that way rather than run casually. Force-pushing replaces what's on the remote — for a solo project with no other collaborators and no open pull requests depending on existing commit hashes, the practical risk is generally low, but it is still a one-way operation on shared, already-pushed history. Take a full backup (a mirror clone: `git clone --mirror`) before attempting it, understand exactly what the rewrite tool is changing before running it, and don't reach for this option first if one of the other three solves the immediate problem.

Even after the underlying condition is genuinely fixed — clean branch deployed, repository public, or plan upgraded — some hosting platforms don't always re-evaluate a project's collaboration status immediately on the next push. If a deployment still shows the identical blocked error after a fix that should have resolved it, try disconnecting and reconnecting the Git integration in your project's settings, or triggering a completely fresh deployment (an empty commit works fine for this) rather than retrying an already-blocked one. If neither clears it, that's a legitimate case for contacting the platform's support directly, since at that point the issue is a stuck internal state on their side, not something fixable from the repository.