domain_create
Create and configure custom domains for services on Railway. Set up HTTPS endpoints, assign target ports, and manage domain mappings for service deployments.
Instructions
[API] Create a new domain for a service
⚡️ Best for: ✓ Setting up custom domains ✓ Configuring service endpoints ✓ Adding HTTPS endpoints
⚠️ Not for: × TCP proxy setup (use tcp_proxy_create) × Internal service communication
→ Prerequisites: service_list, domain_check
→ Alternatives: tcp_proxy_create
→ Next steps: domain_update
→ Related: service_info, domain_list
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| domain | No | Custom domain name (optional, as railway will generate one for you and is generally better to leave it up to railway to generate one. There's usually no need to specify this and there are no use cases for overriding it.) | |
| environmentId | Yes | ID of the environment | |
| serviceId | Yes | ID of the service | |
| suffix | No | Suffix for the domain (optional, railway will generate one for you and is generally better to leave it up to railway to generate one.) | |
| targetPort | No | Target port for the domain (optional, as railway will use the default port for the service and detect it automatically.) |
Implementation Reference
- src/tools/domain.tool.ts:60-68 (handler)Handler function for the domain_create tool, which delegates to domainService.createServiceDomain.async ({ environmentId, serviceId, domain, suffix, targetPort }) => { return domainService.createServiceDomain({ environmentId, serviceId, domain, suffix, targetPort }); }
- src/tools/domain.tool.ts:53-59 (schema)Zod schema defining input parameters for the domain_create tool.{ environmentId: z.string().describe("ID of the environment"), serviceId: z.string().describe("ID of the service"), domain: z.string().optional().describe("Custom domain name (optional, as railway will generate one for you and is generally better to leave it up to railway to generate one. There's usually no need to specify this and there are no use cases for overriding it.)"), suffix: z.string().optional().describe("Suffix for the domain (optional, railway will generate one for you and is generally better to leave it up to railway to generate one.)"), targetPort: z.number().optional().describe("Target port for the domain (optional, as railway will use the default port for the service and detect it automatically.)"), },
- src/tools/domain.tool.ts:32-69 (registration)Definition and registration of the domain_create tool within the domainTools array using createTool.createTool( "domain_create", formatToolDescription({ type: 'API', description: "Create a new domain for a service", bestFor: [ "Setting up custom domains", "Configuring service endpoints", "Adding HTTPS endpoints" ], notFor: [ "TCP proxy setup (use tcp_proxy_create)", "Internal service communication" ], relations: { prerequisites: ["service_list", "domain_check"], nextSteps: ["domain_update"], alternatives: ["tcp_proxy_create"], related: ["service_info", "domain_list"] } }), { environmentId: z.string().describe("ID of the environment"), serviceId: z.string().describe("ID of the service"), domain: z.string().optional().describe("Custom domain name (optional, as railway will generate one for you and is generally better to leave it up to railway to generate one. There's usually no need to specify this and there are no use cases for overriding it.)"), suffix: z.string().optional().describe("Suffix for the domain (optional, railway will generate one for you and is generally better to leave it up to railway to generate one.)"), targetPort: z.number().optional().describe("Target port for the domain (optional, as railway will use the default port for the service and detect it automatically.)"), }, async ({ environmentId, serviceId, domain, suffix, targetPort }) => { return domainService.createServiceDomain({ environmentId, serviceId, domain, suffix, targetPort }); } ),
- src/tools/index.ts:16-37 (registration)Global registration function that includes domainTools (containing domain_create) and registers all tools to the MCP server.export function registerAllTools(server: McpServer) { // Collect all tools const allTools = [ ...databaseTools, ...deploymentTools, ...domainTools, ...projectTools, ...serviceTools, ...tcpProxyTools, ...variableTools, ...configTools, ...volumeTools, ...templateTools, ] as Tool[]; // Register each tool with the server allTools.forEach((tool) => { server.tool( ...tool ); }); }
- src/services/domain.service.ts:16-34 (helper)Supporting service method that implements the core domain creation logic, including availability check and API response formatting.async createServiceDomain(input: ServiceDomainCreateInput): Promise<CallToolResult> { try { // Check domain availability if a domain is specified if (input.domain) { const availability = await this.client.domains.serviceDomainAvailable(input.domain); if (!availability.available) { return createErrorResponse(`Domain unavailable: ${availability.message}`); } } const domain = await this.client.domains.serviceDomainCreate(input); return createSuccessResponse({ text: `Domain created successfully: ${domain.domain} (ID: ${domain.id}, Port: ${domain.targetPort || 'default'})`, data: domain }); } catch (error) { return createErrorResponse(`Error creating domain: ${formatError(error)}`); } }