What causes "Found ${projects.length} existing project(s) in this organization. Pass --project to select one, or re-run without --yes to choose interactively." in mastra-ai/mastra?

Pass --project with the target project's id or slug: `mastra studio deploy --project my-project-slug`

mastra-ai/mastra · error · Error

Found ${projects.length} existing project(s) in this organiz

Error message

Found ${projects.length} existing project(s) in this organization. Pass --project <id-or-slug> to select one, or re-run without --yes to choose interactively.

What it means

In non-interactive (--yes) deploys, resolveProject only auto-selects an existing project when exactly one project's name/slug matches the local package.json name. When the org has other projects and none (or more than one) match, the command throws rather than deploying to the wrong project, and asks you to pass --project or run interactively.

Source

Thrown at packages/cli/src/commands/studio/deploy.ts:324

      projectSlug: projectConfig.projectSlug ?? projectConfig.projectName ?? projectConfig.projectId,
    };
  }

  // 3. Consult the list of existing projects in this org before defaulting to create-new.
  const projects = await fetchProjects(token, orgId);
  const nameMatches = defaultName
    ? projects.filter(proj => proj.name === defaultName || proj.slug === defaultName)
    : [];

  if (projects.length > 0) {
    if (autoAccept) {
      // Non-interactive: only safe to auto-pick when there is exactly one
      // project whose name/slug matches the package.json name.
      if (nameMatches.length === 1) {
        const m = nameMatches[0]!;
        return { existing: true, projectId: m.id, projectName: m.name, projectSlug: m.slug ?? m.name };
      }
      throw new Error(
        `Found ${projects.length} existing project(s) in this organization. Pass --project <id-or-slug> to select one, or re-run without --yes to choose interactively.`,
      );
    }

    const CREATE_NEW = '__create_new__';
    const initialValue = nameMatches.length === 1 ? nameMatches[0]!.id : projects[0]!.id;
    const selected = await p.select({
      message: 'Select a project to deploy to',
      initialValue,
      options: [
        ...projects.map(proj => ({
          value: proj.id,
          label: `${proj.name} (${proj.id})`,
        })),
        { value: CREATE_NEW, label: defaultName ? `＋ Create new project "${defaultName}"` : '＋ Create new project' },
      ],
    });

View on GitHub (pinned to 75dd419e61)

Solutions

Pass --project with the target project's id or slug: `mastra studio deploy --project my-project-slug`
Re-run without --yes and select the project interactively
Align package.json `name` with the existing Studio project name/slug so auto-matching succeeds
Delete obsolete projects in the Studio UI if the ambiguity comes from stale duplicates

Example fix

// before
mastra studio deploy --yes
// Error: Found 3 existing project(s) in this organization...
// after
mastra studio deploy --yes --project my-api

Defensive patterns

Strategy: validation

Validate before calling

const pkg = JSON.parse(readFileSync('package.json', 'utf8'));
const projects = await fetchProjects(orgId);
const matches = projects.filter(p => p.name === pkg.name || p.slug === pkg.name);
if (projects.length > 0 && matches.length !== 1 && !process.argv.includes('--project')) {
  throw new Error('Pass --project <id-or-slug> or run interactively.');
}

Type guard

function hasUniqueProjectMatch(projects: Project[], name: string): projects is [Project, ...Project[]] & { length: 1 } {
  return projects.filter(p => p.name === name || p.slug === name).length === 1;
}

Try / catch

try {
  await studioDeploy({ yes: true });
} catch (e) {
  if (e instanceof Error && e.message.includes('existing project(s) in this organization')) {
    console.error('Run with --project <id-or-slug> or drop --yes to pick interactively.');
    process.exitCode = 2;
  } else throw e;
}

Prevention

Keep package.json `name` identical to the Studio project name/slug
Always pass --project explicitly in CI/automation
Clean up stale projects in the Studio org to avoid ambiguous name matches
Avoid renaming package.json without updating the Studio project

When it happens

Trigger: `mastra studio deploy --yes` against an org that already contains projects, where the local package.json `name` does not uniquely match one project's name or slug (zero matches, or the name matches multiple projects).

Common situations: Renaming package.json `name` after the project was created; reusing an org with many pre-existing projects; monorepo package names diverging from Studio project names; duplicate similarly-named projects causing ambiguous matches.

Related errors

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/9243c50f058abc79. Report an issue: GitHub.