Commissioning a cap league sounds like more work than a redraft league. Capr's answer is a single commissioner hub where every tool lives, plus automation that handles the repetitive parts. Members see the league; you see the league plus one extra room.
The commissioner hub
Everything is a tab in the hub. Queue collects items awaiting your action, including trades waiting on your approval or veto under your league's review mode. Roster Control lets you fix any roster or contract directly, and in salary cap leagues adjust a team's cap. Members manages who's in the league, their co-managers and invite links, and League Listing puts an open seat on Discover. Seats & Buy-In and Dues track who has paid the league fee and, in salary cap leagues, who is covered. League Health surfaces cap, roster and inactivity alerts.
Score Management corrects a stat line or a matchup. Offseason runs or reverses each phase, and Expansion adds teams and runs the expansion draft. Vote Controls extends, closes or cancels a rule vote. Change History is the audit log of every commissioner action. Data Export gets your league's full data out whenever you want it. Bulk Ops applies one change to many teams, with a preview before anything executes and rollback after. Importing a league is part of league setup, so Import League appears only while an import is open: to finish one, or to undo it during the seven days after it goes live. Time Travel moves the league clock forward. Danger Zone holds the irreversible stuff, clearly fenced off.
Expanding the league
Expansion runs during the offseason's Roster Moves phase, after cuts and before free agency. You set how many teams join, how many players each existing team protects (with optional per-position caps), how many players any one team can lose, whether every team loses one before anyone loses two, and whether a team may pull one more player back after a loss. Launching creates the franchises, raises the league size and mints their future rookie picks. Managers then build protection lists against a deadline; anyone who never submits gets an automatic list of their most valuable players.
The expansion draft runs on a pick clock. Contracts travel with the player, with no dead cap for the team that lost him, and a pick must fit under the expansion team's cap. When it ends, the new teams take the rookie draft placement you chose (top of every round, bottom, or standings order), any sandwich or loss-compensation picks are awarded, and Free Agency opens with everyone in it.
The league constitution
Every league gets a versioned constitution: your written rules, with full edit history. When a rule changes, the previous version is preserved, so "what did the rules say when we made that trade?" has an answer instead of an argument. Write it early; versioning does the record-keeping from then on.
Dues tracking
The buy-in tracker records each member's dues status so the money conversation happens once, in one place, instead of every week in the group chat.