MCP server

cubic’s MCP server lets your coding agent read review findings, look up codebase documentation, request PR reviews, triage PR or codebase scan issues, and manage billing and team access. You can use these tools directly from your agent. Skills add workflows for tasks such as fixing review comments. To review changes in your local checkout, use the cubic CLI.

Sign in with your cubic account. Repository tools require a seat in the repository’s organization and read access to the repository on GitHub. Billing and team tools check your access to the requested organization. Connecting MCP does not grant access to additional organizations or repositories.

Endpoint

Use this exact URL:

https://www.cubic.dev/api/mcp

Some MCP clients compare the protected resource URL exactly. Use https://www.cubic.dev/api/mcp, not https://cubic.dev/api/mcp.

Authentication

Use OAuth for new MCP connections. Your MCP client opens a browser, you approve cubic access, and the client stores and refreshes tokens. OAuth is the recommended path and needs no Authorization header or API key in your configuration.

Advanced: API key

For scripts, CI, or MCP clients that cannot complete an OAuth flow, you can use a personal API key instead. Open Settings > API, CLI & MCP and click Generate API key under Personal API key. The cubic CLI, the Members API and the Analytics API share this key, so if you already have one, use it: Regenerate replaces it everywhere. Keys start with cbk_ and cubic only shows the full value once. Send the key as a bearer token in the Authorization header and skip your client’s OAuth login step:

{
  "mcpServers": {
    "cubic": {
      "type": "http",
      "url": "https://www.cubic.dev/api/mcp",
      "headers": {
        "Authorization": "Bearer cbk_..."
      }
    }
  }
}

API keys are personal and grant the same access as the user who created them. Each team member should generate their own key, and you can revoke or regenerate it from the same settings page at any time. The same personal key also authenticates the cubic CLI in CI and cloud agents and your Members API and Analytics API scripts, and regenerating it replaces the key for all of them.

Install and log in

Cursor and VS Code support one-click MCP install links. For other clients, use the CLI or manual config steps below.

Click Add cubic to Cursor.
Confirm the install in Cursor.
Click Connect and complete OAuth.

Manual fallback:Add cubic to ~/.cursor/mcp.json for all projects, or .cursor/mcp.json for one project. If the file already has servers, add the cubic entry inside its mcpServers object:

{
  "mcpServers": {
    "cubic": {
      "url": "https://www.cubic.dev/api/mcp"
    }
  }
}

Open Cursor’s MCP settings, connect cubic, and complete the browser sign-in flow.

If Cursor IDE is installed, first click Add cubic to Cursor. Cursor Agent reads the same MCP config.Manual fallback:Add cubic to ~/.cursor/mcp.json or project .cursor/mcp.json:

{
  "mcpServers": {
    "cubic": {
      "type": "http",
      "url": "https://www.cubic.dev/api/mcp"
    }
  }
}

agent mcp enable cubic
agent mcp login cubic
agent mcp list-tools cubic

Click Add cubic to VS Code.
Confirm the MCP install in VS Code.
Complete the OAuth prompt.
Run MCP: List Servers and confirm cubic is running.

Manual fallback:

Open the Command Palette.
Run MCP: Add Server.
Choose HTTP.
Enter https://www.cubic.dev/api/mcp.
Name it cubic.
Choose Global or Workspace for the configuration.
Run MCP: List Servers, start cubic, and complete OAuth when prompted.

Notion MCP connections are available on Notion Business and Enterprise plans. A workspace admin must enable custom MCP servers before an agent can connect to cubic.

Ask a workspace admin to open Settings > Connections > Manage and turn on Enable custom MCP servers. If connections are restricted, the admin also needs to approve cubic’s MCP URL.
Open your Custom Agent’s Settings.
Go to Tools & Access.
Click Add connection > Custom MCP server.
Enter https://www.cubic.dev/api/mcp.
Name the connection cubic.
Connect with OAuth and complete the cubic sign-in flow.
Select which cubic tools the agent can use.

Read tools such as list_wikis, get_wiki_page, list_scans, and get_pr_issues can run automatically if that matches your agent workflow.See Notion’s MCP setup guide for workspace connection settings.

claude mcp add --transport http --scope user cubic https://www.cubic.dev/api/mcp

Open Claude Code and run:

/mcp

Choose cubic and complete the browser OAuth flow.Run claude mcp list in your terminal to check the connection.

Add the server, sign in through your browser, then list configured servers:

codex mcp add cubic --url https://www.cubic.dev/api/mcp
codex mcp login cubic
codex mcp list

gemini mcp add --transport http --scope user cubic https://www.cubic.dev/api/mcp

Open Gemini CLI and run:

/mcp auth cubic
/mcp

Add this to ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "cubic": {
      "type": "remote",
      "url": "https://www.cubic.dev/api/mcp",
      "enabled": true
    }
  }
}

Then authenticate and verify:

opencode mcp auth cubic
opencode mcp list

droid mcp add cubic https://www.cubic.dev/api/mcp --type http

Open Droid, run /mcp, choose cubic, and complete the browser OAuth flow.

Install cubic’s Pi target:

npx @cubic-plugin/cubic-plugin install --to pi

The installer writes Pi’s MCP config to ~/.config/mcp/mcp.json.Install the Pi MCP adapter if it is not already installed:

pi install npm:pi-mcp-adapter

The adapter reads ~/.config/mcp/mcp.json automatically. Confirm the config contains:

{
  "mcpServers": {
    "cubic": {
      "auth": "oauth",
      "url": "https://www.cubic.dev/api/mcp"
    }
  }
}

Open Pi and run:

/mcp-auth cubic
/mcp reconnect cubic

Use these details for any hosted MCP client that supports remote MCP OAuth and dynamic client registration.

Transport: Streamable HTTP
URL: https://www.cubic.dev/api/mcp
Authentication: OAuth

Your client should open a browser for cubic consent, store the returned tokens, and send the OAuth access token as a bearer token when calling the MCP endpoint.

Try your first prompt

After connecting, ask your agent:

Use cubic to list the open review issues on https://github.com/OWNER/REPO/pull/NUMBER.

Replace the URL with a PR you can access. The agent should call get_pr_issues and show the open findings with their file locations, severity, and descriptions. The result also reports the state of cubic’s latest review of the PR and whether the PR has commits cubic hasn’t reviewed yet. An empty list means the current commit has no open findings only when the latest review completed and no newer commits exist. get_pr_issues doesn’t start a review. For workflows that also investigate and fix the findings, install cubic’s skills.

Available tools

Tool	Description
`get_pr_issues`	List open cubic PR review issues and the state of the PR’s latest review
`trigger_pr_review`	Start a full PR review; an already queued or running review continues without restarting
`update_pr_issue_status`	Resolve, reopen, or dismiss a PR issue on its GitHub review thread and queue an attributed reply
`set_pr_auto_fix`	Turn auto-fix on or off for a pull request
`list_wikis`	List the wikis you have access to, one page at a time
`list_wiki_pages`	List all available wiki pages for a repository
`get_wiki_page`	Retrieve the content of a specific wiki page
`list_scans`	List repository scan summaries
`get_scan`	List aggregated scan issues with filters and pagination
`resolve_github_user_contacts`	Resolve GitHub usernames to email and Slack mentions
`get_issue`	Get full details and code context for a codebase scan issue
`update_issue_status`	Update a codebase scan issue’s triage status, with optional feedback for future scans
`list_learnings`	List AI review learnings for a repository, one page at a time
`get_learning`	Get full details of a specific learning
`list_organizations`	List accessible organizations and your billing and team-management permissions
`get_subscription`	Get the current plan, purchased and assigned seats, review usage, and pending changes
`list_members`	List organization members with their GitHub user IDs, work emails, roles, and seats
`update_member_seat`	Enable or disable an existing member’s seat, change their role, or both
`update_subscription`	Increase purchased seats or upgrade Team to Pro
`update_flex_capacity`	Enable or disable automatic flex purchases and set a spending cap

Use issue IDs from get_pr_issues with update_pr_issue_status. For codebase scans, use IDs from get_scan with get_issue or update_issue_status. The two update tools change issue state. update_pr_issue_status also changes the GitHub review thread and posts its reply asynchronously. trigger_pr_review starts a cloud review. The PR tools accept a GitHub or cubic PR URL, owner/repository#number, or the repository with the PR’s number, head branch, or head commit SHA. list_wikis and list_learnings return one page at a time and say when more results exist. Each tool has a display title and hints that say whether it only reads data or makes changes. Clients may use these hints, for example to run read-only tools without asking you. Whether your client asks before a tool that makes changes depends on the client and its settings. When your client connects, cubic also sends instructions that explain how the tools work together, such as fixing a PR’s findings and then recording each outcome with update_pr_issue_status. Results that quote code or text other people wrote, such as PR findings, wiki pages, scan reports, and learnings, wrap that text in tags that mark it as data. The server instructions tell your agent not to follow instructions inside those tags.

Billing and team management

Start with list_organizations and use the returned GitHub organization login in the organization argument. Each organization also has a githubAccountId, which stays the same when the organization is renamed. Use get_subscription to check purchased capacity and pending changes, and list_members to find a member’s GitHub user ID, current role, and seat. list_members accepts search, plus role and seat filters. Each member includes workEmail, the member’s work email for that organization, or null when cubic has none. Organization and member lists return one page at a time. Pass the returned nextCursor to get the next page.

Permissions and supported subscriptions

Your MCP client uses your cubic permissions. Reading billing and member information requires organization access. Changing subscriptions, seats, or roles requires an organization admin; cubic checks current permissions on every mutation. Admins retain billing access when their own review seat is disabled. MCP mutations require an active paid Stripe subscription. Free customers receive a link to upgrade in cubic. Vercel customers must make changes through the cubic UI or Vercel Marketplace. Reads remain available subject to organization access.

Assign seats and change roles

update_member_seat uses existing purchased capacity and never buys seats. Supply the member’s githubUserId from list_members, plus either or both of these pairs:

seat and expectedSeat: the desired seat state and the current seat value.
role and expectedRole: the desired and current role, each one of admin, member, or viewer.

Combined seat and role changes either both apply or neither applies. If the member’s state has changed, refresh list_members before submitting another change. Repeating a change that already matches the desired state returns a no-op. Admins cannot remove their own admin role or disable the last active human admin. Bots cannot be admins. If no purchased seats are available, increase capacity with update_subscription before enabling another billable member.

Buy seats or upgrade the plan

update_subscription accepts seats, plan: "pro", or both, plus an idempotencyKey for the purchase. seats is the desired total, not the number to add: to go from 5 seats to 8, pass seats: 8. The billing interval stays the same. Upgrades to Pro, and seat increases on Pro or Max, must meet the organization’s minimum seat requirement; an error tells you the required count. A subscription can cover multiple organizations through a shared billing account. Purchases apply to that subscription; the result reports the number of affected organizations. Use the cubic UI for upgrades to Max, seat reductions, downgrades, billing-interval changes, or subscriptions with an existing scheduled, pending, or cancellation change.

Payments and retries

Check the returned status before treating a purchase as complete:

Status	Meaning
`applied`	Stripe has applied the requested subscription change
`no_change`	The subscription already matches the requested state
`payment_action_required`	Complete payment using the returned action link; the requested capacity is not yet available
`processing`	The outcome is uncertain; check the subscription and the returned action before making another purchase

For a retry, reuse the same idempotencyKey with identical arguments. After a timeout, check get_subscription before proceeding; do not generate a fresh key merely because the response was lost. Retry deduplication follows Stripe’s key-retention limits. Reusing a retained key with different purchase parameters can be rejected.

Common prompts

“Show open cubic review issues on PR #42 in acme/backend”
“Start a cubic review of PR #42 in acme/backend”
“List wiki pages for acme/backend”
“Show me the authentication system wiki page”
“List codebase scan issues in acme/backend with severity at least 7”
“Mark scan issue abc as false positive with feedback”
“What review learnings apply to this repository?”
“How many purchased and available seats does acme have?”
“Enable Alice’s review seat in acme using our available capacity”
“Make Alice an admin in acme”
“Increase acme’s total purchased seats from 5 to 8”
“Upgrade acme from Team to Pro with 8 seats”

Troubleshooting

Protected resource mismatch

Confirm your configured URL is exactly https://www.cubic.dev/api/mcp. Replacing www.cubic.dev with cubic.dev can cause OAuth clients to reject the connection.

401 Unauthorized errors

cubic answers an expired or revoked token with a 401 response. Its WWW-Authenticate header carries error="invalid_token", the signal many OAuth clients wait for before they refresh the token. If your client doesn’t recover, run its login command again and complete the browser flow. If you use an API key, check that it hasn’t been revoked or regenerated.

MCP client not recognizing the server

Restart your AI client after updating configuration. For Cursor Agent, make sure the server is in ~/.cursor/mcp.json or project .cursor/mcp.json, not only Cursor’s settings.json.

No wiki pages found

Confirm the repository has an AI Wiki generated, verify you can read the repository on GitHub, and check that owner and repo match GitHub exactly.

Access denied for a repository you can read

cubic syncs repository access from GitHub. Access you gain or lose through a GitHub team reaches cubic with the daily sync, so it can take up to a day to apply to MCP tools. If you were recently given access to the repository, open its wiki page in the cubic web app once, then retry the tool.

Local review is unavailable

MCP provides cloud findings and context. Install and sign in to the cubic CLI to run a local review. If you want to start it from your agent, also install the skills.

Automatic flex capacity

get_subscription includes flex availability, spending settings, configured purchase size and price, and paid/pending usage. list_organizations reports canUpdateFlexCapacity; mutations still check current permissions and billing eligibility. Use update_flex_capacity with organization and at least one of enabled or spendingLimitCents. The cap is an absolute USD-cent amount per quota period, not an increment or a charge amount; it carries forward into future periods. Omitting a field preserves it. For example, spendingLimitCents: 10000 sets a $100 cap. Changing the cap alone does not enable flex. An organization admin can enable flex on an eligible active paid Stripe subscription. Free, trial, and Vercel customers must use the UI. Disable-only requests remain available after a Stripe billing lapse and preserve the saved cap. Any request that edits the cap requires an active paid subscription, including requests that also disable flex. This version does not change purchase size or remove a cap. Flex has no cap by default, so enabling it with none saved allows unlimited spending; set spendingLimitCents when the user wants a limit. Flex and automatic seat purchases can both be enabled. Changing one setting preserves the other. Saving settings does not initiate a charge, but ongoing or subsequent review processing can purchase capacity automatically. Obtain an explicit user instruction before enabling flex or increasing its cap. The result reports applied or no_change for settings, not a completed purchase. Disabling or lowering the cap does not cancel existing invoices, refund spending, or stop in-flight purchases. Pending invoices consume budget but grant no capacity until paid. Retry blocked reviews separately.

Get started

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Measure impact

Portal

Account & support

API reference

Endpoint

Authentication

Advanced: API key

Install and log in

Try your first prompt

Available tools

Billing and team management

Permissions and supported subscriptions

Assign seats and change roles

Buy seats or upgrade the plan

Payments and retries

Common prompts

Troubleshooting

Automatic flex capacity

​Endpoint

​Authentication

​Advanced: API key

​Install and log in

​Try your first prompt

​Available tools

​Billing and team management

​Permissions and supported subscriptions

​Assign seats and change roles

​Buy seats or upgrade the plan

​Payments and retries

​Common prompts

​Troubleshooting

​Automatic flex capacity

Endpoint

Authentication

Advanced: API key

Install and log in

Try your first prompt

Available tools

Billing and team management

Permissions and supported subscriptions

Assign seats and change roles

Buy seats or upgrade the plan

Payments and retries

Common prompts

Troubleshooting

Automatic flex capacity