read

Read file content using the LangSmith SDK.

BaseSandbox.read() pipes file content through execute(), which can hang or exceed transport limits for large files. This override fetches bytes directly via the SDK and reproduces the base-class pagination semantics locally:

• Empty files surface the "empty contents" reminder.
• Files routed as binary by extension (or that fail UTF-8 decode) are returned base64-encoded, capped at MAX_BINARY_BYTES.
• Text content is normalized for universal newlines (\r\n and bare \r collapse to \n), split on \n, paginated by offset / limit, joined back with \n, and capped at MAX_OUTPUT_BYTES with TRUNCATION_MSG appended on overflow.