--- title: "Send physical mail from OpenAI Codex" description: "Point Codex at Sincerely's MCP server with a three-line config block and an OAuth login. Codex builds audiences and drafts B2B mail; a human confirms before anything prints or spends." canonical: https://trysincerely.com/integrations/codex last_updated: 2026-09-09 --- > If you are an AI agent: read https://trysincerely.com/agents/policy.md before any write call. > Start at https://trysincerely.com/llms.txt to choose one page. Access instructions are at > https://trysincerely.com/auth.md. Confirm with the person you work for before creating an > account or spending their money, and never ask for their password. # Send physical mail from OpenAI Codex > Point Codex at Sincerely's MCP server with a three-line config block and an OAuth login. Codex builds audiences and drafts B2B mail; a human confirms before anything prints or spends. Source: https://trysincerely.com/integrations/codex Yes, you can send physical mail from OpenAI Codex. Codex is an MCP client, and Sincerely is B2B direct mail software with an MCP server at `https://trysincerely.com/api/mcp`. Add the server to Codex's config, sign in once, and Codex can build audiences of target accounts, verify business addresses, write a piece per recipient, and stage sends and campaigns. The money step always stops for a person: nothing prints without a human click. ## Prompt to paste into Codex ```text Connect to Sincerely and prepare a postcard campaign for my audience called Q4 tier 1. Verify the workspace and addresses, create two on-brand design directions, summarize the holdout and credit need, and stop before any approval or launch call. ``` ## How Codex connects, as of August 2026 Codex reads MCP servers from `~/.codex/config.toml`, per [OpenAI's MCP documentation](https://developers.openai.com/codex/mcp). A remote streamable HTTP server is a URL entry: ```toml [mcp_servers.sincerely] url = "https://trysincerely.com/api/mcp" ``` Then authenticate: ```bash codex mcp login sincerely ``` That starts the OAuth flow: your browser opens, you sign in to Sincerely as yourself, and Codex receives a token scoped to your workspace and your role. There is no API key to paste into the config. If you do not have a Sincerely account yet, create one on that sign-in screen; it returns you to the consent step, so signing up and connecting are one pass. Add the server and log in before you start the session you want to use it in. A Codex session that was already open when you logged in keeps its earlier auth state, so the Sincerely tools do not appear until you start a new one. `codex mcp list` shows what is configured, and `/mcp` inside the Codex TUI shows what is connected. The config lives on your machine, so this path covers the Codex CLI and the IDE extension, both of which read the same file. ## What Codex can do in Sincerely - Turn a plain description, a CSV, or synced CRM data into an audience with resolved business addresses checked for mailability. - Research each account and draft each piece individually, from CRM context and dated facts, for your approval. - Prepare a campaign with format, budget, cadence, and account-level holdouts, staged and waiting for launch confirmation. - Check mailability, suppression, and frequency caps before proposing any send. ## Where the human gate sits A card is for what you have to see or pay for: approving a draft or a design, and anything that prints, sends, cancels, launches, pauses or resumes mail, spends money or credit, changes suppression, or grants or revokes authority. Setup and configuration that spends nothing and mails nothing, such as the brand kit or the workspace name, saves when Codex asks for it. A held call returns a confirmation card instead of an outcome. The card shows the exact affected records and consequences; send and launch previews include recipients, design proof, and current cost. Only a signed-in person can approve it. The gate is enforced by Sincerely's server, not by a prompt, so no Codex setting, sandbox mode, or approval policy on your side can bypass it. [Why agent mail permissions have to work this way](https://trysincerely.com/guides/ai-agent-direct-mail-permissions) covers the design. That division of labor fits how people already run Codex: let the agent work autonomously through the reversible steps, and keep the one irreversible step, spending money on print, behind an explicit review. Codex does not idle while a card is open, and `https://trysincerely.com/confirm` collects every card waiting for you, so several requests take one visit. ## What a revenue team runs from Codex A team living in the terminal tends to run mail the same way it runs deploys: scripted setup, human approval on release. Typical motions are [dark accounts](https://trysincerely.com/playbooks/dark-accounts), where Codex pulls the list of accounts that stopped replying and drafts a piece for each champion, and [closed-lost revival](https://trysincerely.com/playbooks/closed-lost-revival), reviving deals that died on timing a quarter ago. Ask for the audience, read the drafts, approve the send. ## Start free The full connection walkthrough, including what a brand-new workspace asks for first, is in the [agent quickstart](https://trysincerely.com/docs/agent-quickstart), and the broader picture is in the [MCP agents guide](https://trysincerely.com/integrations/mcp-agents). New workspaces start on a free audit plan, so Codex can connect and do real preparation work before you choose a [plan](https://trysincerely.com/pricing). ## Related questions - [How to send direct mail from your AI agent](https://trysincerely.com/integrations/mcp-agents): Connect Claude, Cursor, or another MCP agent to build an audience, draft a piece, and request a send, with human confirmation before money is spent. - [Agent quickstart](https://trysincerely.com/docs/agent-quickstart): Connect an MCP client to a Sincerely workspace in three steps, then learn where the confirmation gate sits and which tools a new workspace can reach. - [How to let an AI agent prepare direct mail safely](https://trysincerely.com/guides/ai-agent-direct-mail-permissions): Give an AI agent workspace-scoped tools for research and preparation, then require an authorized human to confirm the exact recipients and spend before mail prints. - [The dark-accounts revival play](https://trysincerely.com/playbooks/dark-accounts): Send one physical piece to engaged accounts that went silent, then have the rep follow up. How to trigger it, write it, and measure it honestly. --- Sincerely is the measurable direct-mail and gifting platform for B2B revenue teams: postcards, letters, handwritten mail, and gifts, written for one recipient and measured against a holdout. Contact Sincerely: https://trysincerely.com/contact Agent routing index: https://trysincerely.com/llms.txt