invite_member

Invite someone to a project by e-mail (project owner only). Nobody is added directly: the address gets an invitation e-mail and a pending invitation that the invitee accepts or declines themself (in their inbox after signing in), and the answer is the same whether or not the address has an account. Inviting into a private project makes it shared. role: editor (can change issues) or viewer (read-only). The number of invitations per day is limited.

• 2026-10-04 — A project is capped at its owner's plan seats (members plus pending invitations; Free: 5): a full project refuses with code plan_limit_reached and details {limit: project_members, used, max, plan, subject}; re-inviting a pending address or inviting a member (a role change) takes no new seat.
• 2026-09-30 — Always creates a pending invitation, with the same answer whether or not the address has an account; the invitee accepts or declines. Nobody is added directly any more.
• 2026-10-03 — Also answers structuredContent (see outputSchema); a failed call adds structuredContent.error. Text unchanged. Details: /docs/mcp, "Structured results and errors".
• 2026-10-04 — Claude Code 2.1.288+ (clientInfo claude-code): the text of a successful answer is itself up to 512 bytes, else "Result in structuredContent (N bytes)."; structuredContent and errors are unchanged. See /docs/mcp.