var svgCaptcha = require('svg-captcha'); session.code = [] router.get('/bb', async (ctx, next) => { ctx.set('Access-Control-Allow-Origin', '*'); var captcha = svgCaptcha.createMathExpr({ ignoreChars: '0o1i', color:false, noise:0 }); session.code.push(captcha.text) ctx.body = captcha })