prismsplit

PrismSplit lets your AI assistant manage shared expenses.

CommunityOnlineNo sign-inGlobalFreeCan modify data

What it can do

  • List Groups: List the bill-splitting groups the user belongs to (including 1:1 friend groups). Returns id, name, member_count, type. Use the id to filter list_bills.
  • Get Balances: Get who owes whom from the user's point of view across all their groups. Positive = they are owed, negative = they owe. Money amounts, not advice.
  • Get Quota: Get the user's plan tier and daily usage: bills created today, the daily bill limit, and how many bills they can still create today. Use this to answer "how many bills can I still create" b

What data it sees

Do you need an account

No: the server works without sign-in

PrismSplit lets your AI assistant manage shared expenses. Read your bill-splitting groups, bills, balances and spending stats; create equal-split bills; add members; and request settlements - using the same RPCs, RLS, limits and confirmations as the app. Money-writes require preview-then-confirm, and settlements only create a PENDING request the other person confirms in-app, so nothing moves money on its own.

How to connect

How to connect prismsplit to Claude

The server address to paste into Claude settings:

https://prismsplit.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect prismsplit to ChatGPT

The server address to paste into ChatGPT settings:

https://prismsplit.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect prismsplit to Cursor

The server address to paste into Cursor settings:

https://prismsplit.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (20)

Raw names from tools/list. Only developers need these.

list_groupsList the bill-splitting groups the user belongs to (including 1:1 friend groups). Returns id, name, member_count, type. Use the id to filter list_bills.
get_balancesGet who owes whom from the user's point of view across all their groups. Positive = they are owed, negative = they owe. Money amounts, not advice.
get_quotaGet the user's plan tier and daily usage: bills created today, the daily bill limit, and how many bills they can still create today. Use this to answer "how many bills can I still create" before creating one. Pass the user's IANA timezone for correct local-day reset.
list_billsList recent bills, newest first. Optionally filter by group_id (from list_groups) and a created-at date window (ISO 8601). limit defaults to 20, max 100.
get_billGet one bill in full: totals, tax/tip/discount, items and per-person splits. Pass a bill_id from list_bills.
list_group_membersList the members of a group: member_id, user_id, and name. Use member_id for create_bill participant_member_ids, and user_id for record_payment other_user_id. Call this before splitting a bill among specific people or settling with someone.
get_group_statsSpending summary for a group from the user's POV: monthly totals, lifetime totals, and per-member breakdown. Use for questions like "how much did we spend this month" or "who has paid the most".
list_settlementsList settlements (payments) in a group - history plus any pending ones awaiting confirmation. status is pending/confirmed/rejected. Use for "who still needs to confirm" or "what payments happened".
pingHealth check. Returns "pong" and server time. No data access.
preview_billCompute the exact equal split for a proposed bill and return a per-person breakdown plus a preview_token. ALWAYS call this first and show the breakdown to the user. Then pass the SAME values plus the preview_token to create_bill. No data is written.
create_billCreate an equal-split bill paid by the user. Requires a preview_token from preview_bill and the SAME values. Splits the total equally among participants (or all group members). Subject to the same daily bill limit as the app.
preview_paymentCompute a settlement (who pays whom, how much) and return a preview_token. ALWAYS call this first and show it to the user. No data is written.
record_paymentRecord a settlement between the user and another member. Requires a preview_token from preview_payment with the SAME values. This creates a PENDING request — the other person must confirm it in the PrismSplit app before any balance changes. It does not move money on its own.
add_itemAppend a line item to an existing bill. Pass a bill_id from list_bills/get_bill. Note: this changes the bill — confirm with the user first.
create_groupCreate a new bill-splitting group owned by the user. Returns the group id and an invite_code others can use to join. Use this to start a fresh trip/household/event.
add_memberAdd a person to a group as a guest (someone without a PrismSplit account, so you can split bills with them). Registered users join via the invite_code instead. Returns the new member_id (usable in create_bill participants).
update_billUpdate a bill's metadata (title, category, merchant, location). Does NOT change amounts or splits - use the app for those. Pass only the fields to change.
delete_billPermanently remove a bill (soft delete). This is destructive and affects balances. You MUST set confirm=true, and you should confirm with the user first.
list_commentsList the comments/discussion on a bill.
add_commentPost a comment on a bill (visible to the group, like the app's bill discussion).