Each agent and stable subjectId receives an isolated persistent workspace.
The file and terminal toolsets can create and update files there, and those
files remain available to later sessions for the same agent and subject.
Configure the built-in file toolset on the agent:
The toolset provides read_file, write_file, patch, and search_files.
See Built-in agent toolsets.
To include a file in a turn, add a base64 data_url attachment to
user.message. Herm makes the material available to the agent for that turn.
See Send a message with attachments
for the request schema, size limits, and supported media types.
Persistence and scope
- Workspace files are scoped to the authenticated organization, agent, and
stable
subjectId.
- A new session with the same scope sees the existing workspace.
- A different subject receives a different workspace.
- Agent versions do not reset a subject’s workspace.
The public API does not currently expose a general file list, upload, or
download resource. Use message attachments for turn inputs and agent file tools
for workspace operations. Last modified on July 25, 2026
