Anthropic TypeScript SDK Strips Directory Paths from File Uploads — Breaks Skills API

What this error means

Anthropic SDK strips directory paths from filenames in multipart uploads — my-skill/SKILL.md becomes SKILL.md, breaking skills.versions.create() is a Anthropic API failure pattern reported for developers trying to fix anthropic sdk stripping file paths during multipart upload for skills api. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

4 comments. SDK’s getName() does val.split(/[\/]/).pop() with stripPath=true default. Transforms my-skill/SKILL.md → SKILL.md. Breaks beta.skills.versions.create() API which requires top-level directory structure. Affects skill/agent development workflows.

Common causes

• The SDK’s internal uploads.js getName function strips directory paths by default (stripPath=true). This breaks client.beta.skills.versions.create() which requires files to maintain their directory structure (e.g., my-skill/SKILL.md). Developers get API errors with no obvious cause.
• 4 comments. SDK’s getName() does val.split(/[\/]/).pop() with stripPath=true default. Transforms my-skill/SKILL.md → SKILL.md. Breaks beta.skills.versions.create() API which requires top-level directory structure. Affects skill/agent development workflows.

Quick fixes

1. Confirm the exact error signature matches Anthropic SDK strips directory paths from filenames in multipart uploads — my-skill/SKILL.md becomes SKILL.md, breaking skills.versions.create().
2. Check the Anthropic API account, local tool state, and provider configuration involved in the failing workflow.
3. Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

• Verify the command, editor, extension, or API client that produced the error.
• Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
• Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

1. Capture the exact error message and the command, editor action, or request that triggered it.
2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
3. Review the source evidence below and compare it with your environment.
4. Apply one change at a time and rerun the smallest failing action.
5. Keep the working fix documented for the team or deployment environment.

How to prevent it

• Keep provider/tool configuration documented.
• Record non-secret diagnostics such as tool version, provider name, model name, and command path.
• Add a lightweight check before CI or production workflows depend on the tool.

Sources checked

• https://github.com/anthropics/anthropic-sdk-typescript/issues/968

Evidence note: 4 comments. SDK’s getName() does val.split(/[\/]/).pop() with stripPath=true default. Transforms my-skill/SKILL.md → SKILL.md. Breaks beta.skills.versions.create() API which requires top-level directory structure. Affects skill/agent development workflows.

Related errors

• Anthropic skills API file upload error
• Anthropic beta.skills.versions.create fails
• Anthropic SDK multipart form filename handling

FAQ

What should I check first?

Start with the exact Anthropic SDK strips directory paths from filenames in multipart uploads — my-skill/SKILL.md becomes SKILL.md, breaking skills.versions.create() text and the smallest action that reproduces it.

Can I ignore this error?

No. Treat it as a failed Anthropic API workflow until the root cause is understood.

Is this guaranteed to have one fix?

No. The imported evidence supports the troubleshooting path above, but tool behavior can vary by account, plan, version, provider, and local configuration.

How do I know the fix worked?

Rerun the same command, editor action, or request. The fix is working when that action completes without Anthropic SDK strips directory paths from filenames in multipart uploads — my-skill/SKILL.md becomes SKILL.md, breaking skills.versions.create().