Short answer: this is not a generic evergreen coupon page. Z.AI’s official invite rules currently list a 5% instant discount for eligible invited users on their first GLM Coding subscription order. The checkout screen is the final authority before payment.

Referral code: HCDYCPYFCU

Checkout: Open Z.AI subscribe page

What The Current Z.AI Invite Rules Say

The official campaign-rules page, last checked on June 1, 2026, says invited users who register through a unique invitation link or code and complete their first subscription payment for GLM Coding can receive a 5% instant discount on that first order.

The important limits:

  • The discount is for eligible new users or users without previous paid subscription history.
  • It applies only to the current initial GLM Coding subscription order.
  • It does not apply to renewals, upgrades, downgrades, or later subscription orders.
  • It cannot stack with similar first-order discount campaigns.
  • The final amount after discounts and credits must satisfy Stripe’s minimum payment threshold.
  • Z.AI’s backend records control invitation validity.

That is why this page uses cautious language: treat the invite as a checkout-controlled discount, not a permanent public promo code.

Should You Use The GLM Coding Plan?

Use this deal page only for the discount question. The buying decision belongs on the main Z.AI guide:

  • /tools/zai/ - pricing, quotas, supported tools, endpoints, and buyer checklist
  • /models/glm-5.1/ - GLM-5.1 model specs, comparison context, and eval plan

The practical value case is narrow. Z.AI’s GLM Coding Plan gives supported coding tools a lower-cost GLM lane, with GLM-5.1 available for harder coding work and cheaper GLM models available for routine tasks. It is not a free tier, and it is not an unrestricted API subscription.

Quick Buyer Check

Before you pay:

  1. Open the Z.AI subscribe page from the invite link.
  2. Confirm the checkout page shows the expected first-order discount.
  3. Confirm you are buying GLM Coding, not a different service.
  4. Confirm your coding tool is officially supported.
  5. Save the final checkout screen or receipt for your records.

If the checkout screen does not show the discount, do not assume the referral code will be applied later.

Supported Tool Caveat

Z.AI’s docs say GLM Coding Plan usage is limited to officially supported tools and products. The supported-tool docs also distinguish between the OpenAI-compatible coding endpoint and the Anthropic-compatible endpoint used by tools such as Claude Code.

For most buyers, that means:

  • Use /tools/zai/ for setup details before paying.
  • Do not expect unsupported direct SDK/API usage to consume Coding Plan quota.
  • Keep a premium fallback model until GLM-5.1 passes your own repo evals.

Free vs Low-Cost

GLM-5.1 is not the site’s free-coding recommendation. If your query is “free GLM-5.1 coding” or “free AI coding tools no credit card,” start here instead:

Use Z.AI when you are ready to test a low-cost paid coding lane and the supported-tool restrictions fit your workflow.

Sources

Last verified: June 1, 2026. Recheck the checkout screen, campaign rules, supported tools, and final payable amount before purchase.