Railway MCP Server

Instructions

Implementation Reference

• src/tools/service.tool.ts:124-159 (registration)

  Registers the 'service_update' tool with input schema, description, and handler function that calls serviceService.updateService

    "service_update",
    formatToolDescription({
      type: 'API',
      description: "Update a service's configuration",
      bestFor: [
        "Changing service settings",
        "Updating resource limits",
        "Modifying deployment configuration"
      ],
      notFor: [
        "Updating environment variables (use variable_set)",
        "Restarting services (use service_restart)",
        "Triggering new deployments (use deployment_trigger)"
      ],
      relations: {
        prerequisites: ["service_list", "service_info"],
        nextSteps: ["deployment_trigger"],
        related: ["service_restart", "variable_set"]
      }
    }),
    {
      projectId: z.string().describe("ID of the project containing the service"),
      serviceId: z.string().describe("ID of the service to update"),
      environmentId: z.string().describe("ID of the environment to update (usually obtained from service_info)"),
      region: RegionCodeSchema.optional().describe("Optional: Region to deploy the service in"),
      rootDirectory: z.string().optional().describe("Optional: Root directory containing the service code"),
      buildCommand: z.string().optional().describe("Optional: Command to build the service"),
      startCommand: z.string().optional().describe("Optional: Command to start the service"),
      numReplicas: z.number().optional().describe("Optional: Number of service replicas to run"),
      healthcheckPath: z.string().optional().describe("Optional: Path for health checks"),
      sleepApplication: z.boolean().optional().describe("Optional: Whether to enable sleep mode")
    },
    async ({ projectId, serviceId, environmentId, ...config }) => {
      return serviceService.updateService(projectId, serviceId, environmentId, config);
    }
  ),

• src/tools/service.tool.ts:144-155 (schema)

  Zod schema defining input parameters for the service_update tool

  {
    projectId: z.string().describe("ID of the project containing the service"),
    serviceId: z.string().describe("ID of the service to update"),
    environmentId: z.string().describe("ID of the environment to update (usually obtained from service_info)"),
    region: RegionCodeSchema.optional().describe("Optional: Region to deploy the service in"),
    rootDirectory: z.string().optional().describe("Optional: Root directory containing the service code"),
    buildCommand: z.string().optional().describe("Optional: Command to build the service"),
    startCommand: z.string().optional().describe("Optional: Command to start the service"),
    numReplicas: z.number().optional().describe("Optional: Number of service replicas to run"),
    healthcheckPath: z.string().optional().describe("Optional: Path for health checks"),
    sleepApplication: z.boolean().optional().describe("Optional: Whether to enable sleep mode")
  },

• src/tools/service.tool.ts:156-158 (handler)

  Tool handler function for service_update, delegating to serviceService

  async ({ projectId, serviceId, environmentId, ...config }) => {
    return serviceService.updateService(projectId, serviceId, environmentId, config);
  }

• src/services/service.service.ts:126-139 (handler)

  Core handler method in ServiceService that performs the service update via the Railway client API, handles errors, and returns formatted response.

  async updateService(projectId: string, serviceId: string, environmentId: string, config: Partial<ServiceInstance>) {
    try {
      const updated = await this.client.services.updateServiceInstance(serviceId, environmentId, config);
      if (!updated) {
        return createErrorResponse(`Error updating service: Failed to update service instance of ${serviceId} in environment ${environmentId}`);
      }
  
      return createSuccessResponse({
        text: `Service configuration updated successfully`
      });
    } catch (error) {
      return createErrorResponse(`Error updating service: ${formatError(error)}`);
    }
  }