Connect Constants · v1

MCP endpoint: https://mcp.reports.constants.io/mcp (Streamable HTTP). You need a Constants account, a browser for sign-in and consent, and a current Codex or Claude Code client supporting remote MCP and OAuth. Do not place account credentials in prompts or configuration.

Codex

Run in your terminal:

codex mcp add constants --url https://mcp.reports.constants.io/mcp
codex mcp login constants

The browser opens the Constants connection screen. Sign in there if needed, then click Connect to approve a new client. You return to your coding agent automatically; previously approved connections skip the approval screen. Reopen the coding session if the tools are not visible. In Codex desktop, add the same remote endpoint in MCP settings and complete sign-in; refresh the session after configuration changes.

Your client's tool permissions still apply. Starting or verifying a test may show a client approval prompt because it creates a paid execution. A headless Codex session configured to reject all approval prompts can block these calls before they reach Constants. Use an interactive session or explicitly authorize the intended tools in that session's client configuration; account connection alone does not authorize a test.

Claude Code

claude mcp add --transport http constants https://mcp.reports.constants.io/mcp

Inside Claude Code, run /mcp, select Constants, and authenticate in your browser. Restart the session if the connection or tools are not yet visible. You can return to /mcp to inspect connection status.

Current Claude Code versions also support claude mcp login constants and claude mcp get constants in the terminal. Both clients support mcp login constants --no-browser for a manual browser/callback flow when automatic browser opening is unavailable.

First-use prompt

Connect Constants to this coding agent using the linked setup instructions. Inspect this repository to draft a testing brief and audience, and help me select a public preview URL. Complete account connection and show me the proposed test. This setup request does not authorize starting a test.

Setup: https://www.constants.io/docs/agents/

After connection, use get_account to confirm the connection and available workspace credits. Repository inspection stays local. Draft the goal, audience and boundaries, choose a public preview, then present the test. Setup alone starts nothing. If the user's original request already explicitly asked for testing, do not ask for the same authorization again.

Optional plugin

Download Constants plugin v1 and unpack it into a directory you trust:

mkdir constants-agent-v1
curl --fail --location https://www.constants.io/downloads/constants-plugin-1.0.0.tar.gz --output constants-agent-v1/plugin.tar.gz
tar -xzf constants-agent-v1/plugin.tar.gz -C constants-agent-v1

For Codex:

codex plugin marketplace add ./constants-agent-v1
codex plugin add constants@constants

For Claude Code, load the plugin for a session:

claude --plugin-dir ./constants-agent-v1/plugins/constants

Complete the plugin MCP connection's browser OAuth flow when prompted. In Claude Code use /mcp; use /reload-plugins after changing a loaded plugin. In Codex inspect MCP settings after installation and authenticate the Constants server. Do not configure a second copy of the direct MCP server if it is already connected. The shared skills are Test a change, Investigate findings, and Verify fixes.

Advanced configuration

{
  "mcpServers": {
    "constants": { "type": "http", "url": "https://mcp.reports.constants.io/mcp" }
  }
}

This is the Claude/plugin configuration shape; Codex manages its own configuration through codex mcp add. OAuth discovery is at https://mcp.reports.constants.io/.well-known/oauth-protected-resource. The resource audience is https://mcp.reports.constants.io.

Client command references: Codex MCP, Codex plugins, Claude MCP, Claude plugins. Live client acceptance is maintained in the release checklist, independently of command documentation.