vercel/ai · error · Error

Duplicate ACP skill name ${JSON.stringify(skill.name)}.

Error message

Duplicate ACP skill name ${JSON.stringify(skill.name)}.

What it means

Error "Duplicate ACP skill name ${JSON.stringify(skill.name)}." thrown in vercel/ai.

Source

Thrown at packages/harness-acp/src/v1/acp-v1-skills.ts:115

function validateACPSkills({
  skills,
}: {
  skills: ReadonlyArray<HarnessV1Skill>;
}): void {
  const skillNames = new Set<string>();
  for (const skill of skills) {
    if (
      !ACP_SKILL_NAME_PATTERN.test(skill.name) ||
      skill.name === '.' ||
      skill.name === '..'
    ) {
      throw new Error(
        `Invalid ACP skill name ${JSON.stringify(skill.name)}: expected a kebab-case slug.`,
      );
    }
    if (skillNames.has(skill.name)) {
      throw new Error(
        `Duplicate ACP skill name ${JSON.stringify(skill.name)}.`,
      );
    }
    skillNames.add(skill.name);

    const filePaths = new Set<string>();
    for (const file of skill.files ?? []) {
      const normalizedPath = validateACPAttachedFilePath({
        skillName: skill.name,
        filePath: file.path,
      });
      if (normalizedPath === 'SKILL.md') {
        throw new Error(
          `Invalid ACP skill file path ${JSON.stringify(file.path)} for skill ${JSON.stringify(
            skill.name,
          )}: SKILL.md is reserved for the skill definition.`,
        );
      }

View on GitHub (pinned to 69428b1f8b)

When it happens

Trigger: Thrown at packages/harness-acp/src/v1/acp-v1-skills.ts:115 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of vercel/ai@69428b1f8b (2026-08-30). Data as JSON: /api/errors/667d956c7b485cfe. Report an issue: GitHub.