v0.16.0

In short

• Fixed: listEvents lists a whole day when it is asked for one date (2026-10-15 to 2026-10-15): it returned
  nothing, with no error, so an assistant answered that the day was free. A date without a time is now a day in
  local time.
• Fixed: a folder address written with a trailing slash is accepted; createFolder answered "Folder not found".
• Changed: three answers now tell an assistant what it needs to go on: an empty search of several words says
  why it found nothing, a draft whose recipient has no e-mail address carries a warning, and renameFolder returns
  the new address of the folder.
• The bridge does not change in this release: nothing to update in your MCP clients if their bridge is 0.14.0. A
  bridge 0.13 keeps working; updating it is optional.
• No call that worked stops working. Updating is not urgent.

How to update

• Thunderbird add-on: it updates itself. To get this version now: Add-ons and Themes, gear menu, Check for Updates, then restart Thunderbird. For a first installation, see the README (commonpost-mcp-v0.16.0.xpi below).
• MCP bridge: it is installed in your MCP client and is never updated automatically. This release ships the same bridge as v0.14.0: a bridge of version 0.14.0 needs no update.
  • Claude Desktop: download commonpost-mcp-v0.14.0.mcpb below and open it with Claude Desktop; if the file does not open there (Windows), use Settings > Extensions > Advanced settings > Install Extension.
  • Other clients (Claude Code, Cursor, VS Code, ...): download mcp-bridge.cjs below and put it in place of your copy, then restart the client or reconnect the server (/mcp in Claude Code). The path of your copy is in the MCP configuration of the client (Claude Code: claude mcp get <server name>).
  • Not sure which bridges you have? The options page of the add-on (section Bridge) lists the bridges that connected, each with its version and "Up to date", "Newer version available" or "Update recommended". Claude Desktop and another client on the same computer are two bridges, updated separately.

The .sigstore.json files are provenance attestations, not something to install.

All changes

Changed

• searchMessages adds a hint to an empty result of a search of several words: every word must match as written,
  and a single leading operator (from:Carol training budget) sends every word to that field. Results that found
  something are unchanged.
• sendMail, saveDraft, replyToMessage and forwardMessage add a warning when a recipient has no e-mail address
  (to: "Frank Osei"): the draft was saved and reported as a success, addressed to nobody. The call still succeeds,
  because the name of a Thunderbird mailing list is such a recipient too. A direct send that fails names it as the
  likely cause.
• renameFolder returns the new URI of the folder as path, next to oldPath, and says so in its message: a caller
  that went on with the old URI got "Folder not found".

Fixed

• listEvents lists a whole day when startDate and endDate are the same date without a time (2026-10-15): it
  returned an empty list, with no error, and an assistant answered that the day was free. A date without a time is now
  a calendar day in local time: as startDate the start of that day, as endDate the end of it. A date with a time
  is read as before.
• A folder URI written with a trailing slash (mailbox://nobody@Local%20Folders/) is accepted wherever a tool takes
  a folder: createFolder answered "Folder not found" for it. moveFolder still says "already under this parent"
  when that parent is written this way.
• Release pages name the .mcpb file as it is published. The bundle carries the version of the bridge, so a release
  that does not change the bridge ships the bundle of an earlier version: the page of 0.15.0 said
  commonpost-mcp-v0.15.0.mcpb for the file commonpost-mcp-v0.14.0.mcpb (corrected by hand on that page).