RSMF (Relativity Short Message Format)
An open export format for chat and text-message evidence: an RFC 5322 message wrapping an rsmf.zip archive whose rsmf_manifest.json lists participants, conversations and every event with its timestamp, sender, text, reactions, edits, attachments and (in version 2.0) direction and read receipts.
What You Need to Know
Relativity published RSMF so that short-message data from any platform — SMS, iMessage, WhatsApp, Slack, Teams, Bloomberg and dozens more — could be reviewed in one normalized form. Review platforms (Relativity, Reveal) write it when they export a conversation; collection tools (Hearsay, iMazing, Message Crawler, ChatExport) write it directly from a phone, a backup or an account. The file is an email-shaped wrapper with X-RSMF headers (version, generator, application, custodian, begin and end dates, event count) around one base64 zip attachment named rsmf.zip. Inside, rsmf_manifest.json carries four root properties: version, participants, conversations and events. RSMF 2.0 added message direction, read receipts, history events, account identifiers and an event-collection id. Relativity recommends at most 10,000 events per file and publishes a validator and the JSON schema. ExhibitPrep reads RSMF 1.0 and 2.0 in the browser and renders each conversation as a dated, searchable transcript PDF whose first page records the export's SHA-256, its headers and the validation outcome; the transcript is then stamped like any exhibit.
Put this into practice
Use the step-by-step help to prepare and check your files. Definitions explain the terms; the rules and orders for your matter determine what is required.
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Frequently Asked Questions
How is an RSMF file different from screenshots of a text thread?
Screenshots show a cropped view with abbreviated times and whatever contact name the phone displayed. An RSMF export carries every event with a full ISO 8601 timestamp, the sender's account identifier as collected, deleted and edited messages, reactions, attachments and the collection's own headers, in a structured file that a review platform can validate against the published schema. A transcript rendered from it can state exactly how many of the conversation's events it carries.
Does an RSMF transcript settle who sent the messages?
No. The format records what the exporting tool collected; the questions of who sent a message and what it establishes remain the proponent's to answer under the rules that apply in the court, beginning with Federal Rule of Evidence 901, with hearsay analysed separately. The help article on preparing text-message exhibits lists the rules commonly in play.
When It's Used
The interchange format between collection tools, review platforms and exhibit preparation
Example
"A client's iPhone thread collected by Hearsay, exported as one .rsmf file per conversation, opened in ExhibitPrep and rendered as Exhibit 12, a 14-page transcript with the export's hash on page 1."
Related Terms
ESI (Electronically Stored Information)
Digital evidence including emails, databases, social media posts, text messages, and metadata. Subject to special discovery rules.
Metadata
Hidden data embedded in electronic documents showing author, creation date, edit history, and other file properties.
Bates Numbering
A method of indexing legal documents by placing unique, sequential numbers on each page. Originally created by the Bates Automatic Numbering Machine.
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