This guide shows you how to configure the Sita MCP server in Codex CLI to enable powerful codebase Q&A capabilities.
You must configure the MCP server for each repository you want to work
with. Each repository requires its own configuration section with a unique
repo ID.
Important: Codex CLI uses mcp_servers (with underscore) as the top-level
key, not mcpServers like JSON-based tools.
Configuration Steps
Locate Configuration File
Open the Codex CLI configuration file located at:Create this file if it doesn’t exist. Add MCP Server Configuration
Add an mcp_servers section to your TOML configuration file.
Configure Sita Server
Add the Sita MCP server configuration using TOML format (see examples below).
Save and Restart
Save the configuration file. The MCP server will be available next time you use Codex CLI.
Single Repository Configuration
To configure Sita for a single repository, add this to your ~/.codex/config.toml:
# IMPORTANT: Use mcp_servers (with underscore), not mcpServers
[mcp_servers.sita-qna]
command = "npx"
args = [
"-y",
"mcp-remote",
"http://localhost:3000/api/mcp",
"--header",
"x-repo-id: YOUR_REPO_ID"
]
env = { "NODE_ENV" = "production" }
Replace YOUR_REPO_ID with your repository ID. The repo id can be copied from
repos tab.
Multiple Repository Configuration
To configure multiple repositories, add separate server entries for each:
[mcp_servers.frontend-qna]
command = "npx"
args = [
"-y",
"mcp-remote",
"http://localhost:3000/api/mcp",
"--header",
"x-repo-id: frontend-app"
]
[mcp_servers.backend-qna]
command = "npx"
args = [
"-y",
"mcp-remote",
"http://localhost:3000/api/mcp",
"--header",
"x-repo-id: backend-api"
]
[mcp_servers.mobile-qna]
command = "npx"
args = [
"-y",
"mcp-remote",
"http://localhost:3000/api/mcp",
"--header",
"x-repo-id: mobile-app"
]
Give each server configuration a descriptive name (like frontend-qna,
backend-qna) to easily identify which repository it connects to.
Using Environment Variables
You can use an environment variable for the repo ID with the env field:
[mcp_servers.sita-qna]
command = "npx"
args = [
"-y",
"mcp-remote",
"http://localhost:3000/api/mcp",
"--header",
"x-repo-id: ${REPO_ID}"
]
env = { "REPO_ID" = "your_repo_id" }
Create Configuration via Command Line
You can create the configuration file with this command:
mkdir -p ~/.codex && cat > ~/.codex/config.toml << 'EOF'
[mcp_servers.sita-qna]
command = "npx"
args = [
"-y",
"mcp-remote",
"http://localhost:3000/api/mcp",
"--header",
"x-repo-id: YOUR_REPO_ID"
]
EOF
Then edit the file to add your actual repository ID:
nano ~/.codex/config.toml
Verification
After adding the configuration:
- Save the
~/.codex/config.toml file
- Run Codex CLI with a query about your codebase
- The MCP server tools should be available for use
If you encounter a “string does not match pattern” error, it may indicate a
compatibility issue between the MCP server’s tool naming convention and Codex
CLI’s validation rules. Contact support if this occurs.
Next Steps
- Set up MCP in Claude Code for CLI integration
- Configure Cursor with MCP support
- Try Cline for VSCode integration