Content Version

A Content Version in Salesforce (ContentVersion in the API) is the standard child object in the Salesforce Files framework that holds the actual binary content for one specific version of a Content Document. Each Content Version record contains the file's binary data in the VersionData field (stored base64-encoded over the API), along with metadata like Title, FileType, FileExtension, ContentSize, VersionNumber, IsLatest flag, ReasonForChange (free-text explanation of what changed in this version), and a parent ContentDocumentId. When a file is first uploaded, Salesforce creates one Content Version record (the initial version, with VersionNumber = 1 and IsLatest = true) plus its parent Content Document. Subsequent file replacements insert new Content Version records under the same Content Document, each incrementing VersionNumber and flipping IsLatest on the prior version. Apex and API code that uploads files always inserts Content Version (not Content Document) — the platform automatically creates the parent Content Document and the initial Content Document Link to the inserting user.

Content Version is the only file-related object you should insert directly through API or Apex. The platform automatically derives the parent Content Document Id and creates an initial Content Document Link to the inserting User on first insert. Subsequent versions of the same file are inserted by setting ContentDocumentId to the existing parent's Id rather than letting Salesforce generate a new one — this keeps the version chain intact rather than creating an unrelated new file. Bulk uploads via the Bulk API support chunked uploads for files over the standard REST limit (up to 2 GB depending on edition).

VersionData is base64-encoded in API responses, which inflates the apparent size by roughly 33% — a 1MB raw file becomes ~1.33MB over the wire. Plan governor limits and heap sizes accordingly when bulk-uploading files via Apex, and prefer the Bulk API or chunked upload patterns for files over a few megabytes. Querying VersionData through SOQL is allowed but expensive; for analytics that don't need the actual binary, exclude VersionData from the SELECT to avoid inflating query response sizes.

The IsLatest flag is auto-maintained by Salesforce — every time a new Content Version is inserted under an existing Content Document, the prior IsLatest version flips to false and the new one becomes IsLatest = true. Don't manually update IsLatest, since the platform also maintains LatestPublishedVersionId on the parent Content Document and the two must stay in sync. Direct manipulation breaks the version-history UI and can cause unpredictable file-display behavior.