Claude Files and Skills APIs Now GA: Migration Guide

Anthropic has announced that Claude's Files API and Skills API have officially reached GA (General Availability). For developers already using the beta versions, this means removing two beta headers, adjusting the file expiry policy, and switching to cursor-based pagination. The official guidance provides type-checking steps for TypeScript and Python to help ensure a smooth migration.

Both APIs Are Now GA; Beta Headers No Longer Needed

Previously, the Files API and Skills API were in beta, requiring specific beta identifiers in request headers. With GA, both APIs are now part of the stable release, and developers no longer need to add beta headers. The official announcement explicitly states: "drop two beta headers"—simply remove the two beta headers.

This change may seem minor but affects all existing integrations. If your code enables beta features for Files or Skills via the anthropic-beta header or other means, you need to check and remove the relevant configuration. Otherwise, requests may be rejected due to unknown header fields or behave unexpectedly.

The first step in migration is to review the request construction logic in your codebase. TypeScript users typically set beta headers during client initialization or in per-request options; Python users do the same. It's recommended to search globally for beta-related strings to determine which belong to Files/Skills and which are still used by other features.

GA (General Availability) is a key milestone in a software product's lifecycle, typically indicating that the interface has been thoroughly tested, has official long-term support commitments, and is covered by stability and compatibility guarantees. In contrast, the beta phase means features may change and are not recommended for critical production workloads. For API products, GA often comes with version freezing, clear SLAs (Service Level Agreements), and published deprecation policies. Therefore, migrating from beta to GA is not just a superficial change like removing the anthropic-beta request header; it means the interface contract is becoming stable: future breaking changes will generally go through a formal deprecation cycle rather than arbitrary adjustments. When planning long-term architecture, developers can treat GA interfaces as reliable foundational components, while retaining fallback options for beta features. Understanding this distinction helps prioritize this migration: production dependencies should be migrated as soon as possible to avoid call failures once beta headers are completely removed.

File Expiry Extended to 90 Days

A practical improvement in the GA version is that file expiry can now be set up to 90 days. The beta phase may have had shorter expiry policies, which were not flexible enough for scenarios requiring long-term storage of uploaded files (such as knowledge base documents or persistent resources).

Developers can now specify longer validity periods when creating files, reducing the operational burden of periodic re-uploads. However, 90 days is not permanent storage; you still need to design renewal or rebuild mechanisms. The official announcement only mentions "add file expiry up to 90 days" without specifying whether the default value has changed, so you should explicitly set expiry times during migration to avoid relying on implicit behavior.

For the Skills API, file lifecycle is equally important. If skill-related resource files expire, skill invocations may fail. It's recommended to add an item to your migration checklist: review all file creation calls and confirm that expiry parameters have been adjusted to the new maximum.

Pagination Switches to Cursors

Another change to note is the pagination mechanism. The announcement states "switch to page cursors"—moving from the previous pagination method to cursor-based pagination. Cursor pagination is more stable with large datasets and avoids duplicates or omissions caused by data additions or deletions.

During migration, you need to check all calls that list files or skills. If you previously used offset/limit or page number parameters, you now need to pass a cursor parameter and read the next_cursor from the response. The TypeScript and Python SDK type definitions will reflect this change; the official emphasis on "Type-checked TS and Python steps" means type checking can help identify incompatible calls.

It's recommended to run a full list traversal test after migration to confirm correct cursor passing and proper termination conditions. Logic that caches paginated results locally should also be adjusted accordingly.

Cursor-based pagination is a pagination method that uses an opaque cursor to mark the "end position of the previous page," as opposed to offset/limit or page-number-based pagination. Traditional offset pagination is prone to issues when data is frequently added or deleted: if records are deleted after the first page, the second page will skip entries that should appear; if new records are inserted, they may be returned again. Cursor pagination uses the next_cursor returned by the server to precisely locate the continuation point, making it more stable when data changes dynamically and typically offering better query performance, especially for large result sets. The trade-off is that cursors generally only move forward sequentially, cannot jump to arbitrary pages, and are usually not suitable for long-term caching or cross-session reuse. During migration, pay attention to whether the response provides termination flags like has_more, and how errors are handled when a cursor becomes invalid—when the data corresponding to a cursor is deleted, some implementations return an error rather than an empty result.

TypeScript and Python Migration Steps

The official migration path emphasizes type checking. For TypeScript projects, after upgrading the SDK, run tsc --noEmit or your project's type-check command; the compiler will flag locations still passing beta headers or using old pagination parameters. Python projects can use type annotations and tools like mypy, combined with the SDK's stub files, to detect mismatches.

The specific steps can be summarized as: upgrade to an SDK version that includes GA support; remove beta header configurations related to Files/Skills; adjust expiry times in file creation calls to a maximum of 90 days; change pagination parameters in list calls to cursors; run type checking and fix errors; finally, verify file upload, listing, and skill invocation flows in a test environment.

Since the original announcement does not provide more detailed code examples, it's recommended to refer to the official SDK changelog and type definitions. The value of type checking lies in catching runtime errors at compile time, which is especially suitable for changes involving request headers and pagination parameters.

Practical Impact on Developers

This GA marks the transition of Files and Skills from experimental features to stable interfaces. For teams relying on these two APIs in production, the migration window needs planning: after beta headers are removed, old code may fail directly; pagination changes may cause list logic to fail silently.

The increase in file expiry limit to 90 days is beneficial, but it also reminds developers that storage is not permanent and expiry handling must be considered in the architecture. Overall, the migration workload is not large, but details are easy to miss; type checking is the core method recommended by the official guidance.

It's recommended that teams first run the complete flow in a non-critical environment after upgrading the SDK, then gradually roll out. For projects using both Files and Skills, note the shared beta header configuration to avoid changing only one place.

(This article is based on Anthropic's official announcement and RSS source information; refer to the official documentation for specific parameters.)

One-line Summary

Anthropic's Files and Skills APIs are now GA; developers need to remove beta headers, adapt to 90-day expiry, and cursor-based pagination.

Paragraph Summary

Anthropic has announced that Claude's Files API and Skills API have officially reached GA. For developers already using the beta versions, migration points include: removing two beta request headers, adjusting file expiry to a maximum of 90 days, and switching list calls from the previous pagination method to cursor-based pagination. The official guidance emphasizes using TypeScript's tsc --noEmit and Python type checking (such as mypy) to detect incompatible calls, catching runtime errors at compile time. The article outlines the impact of each change and migration steps, reminding developers that old code may fail directly due to beta header removal, pagination changes may cause list logic to fail silently, the increased file expiry limit still requires designing renewal mechanisms, and it's recommended to run the complete flow in a non-critical environment before gradual rollout.