How to Connect Cloudflare D1 to Codex
Query your Cloudflare D1 data directly from Codex using Sequel’s MCP server. Ask questions in plain English, with no SQL, no dashboards, and no context switching.
Short answer
Connect Cloudflare D1 to Sequel, then add Sequel's MCP server to Codex using the config on this page. Codex can then query your live Cloudflare D1 data in plain English, with no connector code and no CSV exports. Both steps take a few minutes.
Everything you can ask Codex about your Cloudflare D1 data.
Ask in plain English — Sequel translates it into a Cloudflare D1 query, runs it, and Codex hands back the answer. No SQL, no dashboards, no CSV exports.
- How many rows are in each table?
- Show me the 20 most recently created users.
- What is the conversion rate from signup to first purchase, by month?
- Which customers signed up last quarter and are still active?
- Find duplicate email addresses in the users table.
How it works
Three steps to get started
Connect Cloudflare D1 to Sequel
In your Sequel dashboard, go to Connections and add Cloudflare D1. Sequel handles authentication and schema discovery automatically.
Add Sequel to the agent
Copy the Sequel MCP configuration into Codex's settings file (shown below). Swap in your API key from Settings → API Keys.
Ask Codex about your data
Restart Codex and start asking questions. "How many rows are in each table?" — and get a real answer backed by live Cloudflare D1 data.
Why Codex
What Codex does with your Cloudflare D1 data
Grounded answers from real data
Codex with Sequel queries your actual databases before generating code or explanations. Every schema reference, column name, and data shape is verified against what's really there.
Terminal-native data access
No context switching — Codex can pull database data mid-session to inform code generation, write migrations based on actual schemas, and validate assumptions without leaving the terminal.
Agentic data workflows
Codex's multi-step agent can chain Sequel tool calls together: discover schema, sample data, run analysis, then generate code — all in one automated flow.
Configuration
Add Sequel to Codex
Place this in ~/.codex/config.yaml and replace sql_your_api_key with a key from Settings → API Keys.
~/.codex/config.yaml
mcp_servers:
sequel:
type: http
url: https://api.sequel.sh/mcp
headers:
Authorization: "Bearer sql_your_api_key"Install
Install Cloudflare D1 MCP in Codex
Pick your app and Sequel installs itself: a one-click link where the client supports it, that client’s own few steps where it doesn’t. Every route signs in with your Sequel account over OAuth, so there is no API key to copy and nothing to keep in sync.
Already have an MCP client?
https://api.sequel.sh/mcp
Add it as a remote (streamable HTTP) server and sign in when prompted. Skills come with it; nothing else to install. Manual setup per client
Add Sequel to Codex
Terminal
codex mcp add sequel --url https://api.sequel.sh/mcp
- 1Run the command in your terminal. It writes the server to ~/.codex/config.toml.
- 2Run codex mcp login sequel and sign in in the browser.
- 3Start Codex and ask a question.
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Tell your Grok bot to add Sequel and it can query every database and marketing tool you've connected.
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Give Meta's Muse one message and it builds its own connector to every source you've put in Sequel.
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Add Sequel once in ChatGPT and your dot can answer data questions on its own, day and night.
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Ask your Ahrefs SEO data anything: backlinks, keywords, and traffic.
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Frequently asked questions
How do I connect Cloudflare D1 to Codex?
You need two things: (1) connect Cloudflare D1 to Sequel in your Sequel dashboard under Connections, and (2) add the Sequel MCP config to Codex using the setup shown above. Once both are done, Codex can query your Cloudflare D1 data directly.
What Cloudflare D1 data can Codex access?
Codex can access any data available through your Cloudflare D1 connection in Sequel. Use Sequel's search tool to discover available metrics and dimensions, then execute queries to pull the data you need.
Is my Cloudflare D1 data sent to Codex's servers?
Query results are returned to Codex as context within your conversation. Only the data you explicitly ask about is retrieved. Sequel never stores your query results permanently — they exist only for the duration of the tool call.
Do I need a Sequel account?
Yes. You need a Sequel account to connect Cloudflare D1 and generate an API key. Sign up free at sequel.sh — no credit card required. Then create a connection to Cloudflare D1 and generate an API key from Settings → API Keys.
Can I connect multiple Cloudflare D1 accounts?
Yes. Sequel supports multiple connections of the same type. If you have multiple Cloudflare D1 accounts or properties, add each as a separate connection in Sequel. Codex will be able to query all of them.
How do I configure Sequel for Codex CLI?
Add the Sequel MCP server to ~/.codex/config.yaml as shown above. Create the file if it doesn't exist. Replace `sql_your_api_key` with a real key from Settings → API Keys, then restart Codex.
Does Codex CLI support HTTP MCP servers?
Yes. Codex CLI supports MCP over HTTP (Streamable HTTP transport). The `type: http` field in the config tells Codex to use this transport when connecting to Sequel.
Can I limit which databases Codex can access?
Sequel MCP is scoped to your organization's connected data sources. You can create separate API keys for different environments and revoke them at any time from Settings → API Keys.
Is this the same as the original OpenAI Codex model?
No — Codex CLI is OpenAI's agentic terminal coding tool, separate from the original Codex language model. It uses the latest OpenAI models (GPT-4o and o-series) with MCP tool support.
How does Sequel connect to Cloudflare D1?
Through Cloudflare's D1 REST API. You sign in with Cloudflare, approve the connection, and choose which D1 database to connect. Sequel stores the resulting tokens encrypted and refreshes them automatically, so there is no API token to create, paste, or rotate by hand.
Can one connection reach more than one database?
No. You pick exactly one D1 database when you connect, and that choice is baked into the connection. Sequel has no tool that can list or query any other database. If you want to query a second database, add a second connection.
Is it read-only?
Yes, and it is enforced by Cloudflare rather than by us. Sequel requests only the D1 Read scope, so Cloudflare itself rejects any write that reaches the D1 API. The tools Sequel exposes are query and schema introspection, and nothing in the connector can create, update, or delete data.
Do I need to move my data anywhere?
No. Sequel queries D1 directly over Cloudflare's API. Nothing is copied into a warehouse and there is no sync to schedule. Query results are stored so you can export them, but your tables stay where they are.
Connect Cloudflare D1 to Codex today
Sign up free, connect your data sources, and start querying in minutes.