Claude to GLM-5.1 in 10 Minutes: The OpenClaw Migration Guide

Why Read This Post (Not the GLM-5.1 Announcement)

If you are brand new to GLM-5.1 and want to understand the model, the benchmarks, and the pricing, start with the GLM-5.1 announcement post. It covers the 744B MoE architecture, the SWE-Bench Pro score of 58.4, the Huawei Ascend training story, and the one-liner to try the model from scratch.

This post is different. It assumes you already read that, you are convinced, and you have a working Claude-backed OpenClaw setup you want to move over without breaking anything. No benchmark tables, no architecture explainers — just the steps, the diffs, and the pitfalls.

Prerequisites

If any of those are missing, fix them first. Trying to migrate a half-broken agent is how you end up blaming the model for a config bug.

Step 1: Get a Z.ai API Key

Head to docs.z.ai and sign up for an account. After email verification, navigate to the API keys section and generate a new key. The GLM Coding Plan is what you want — promotional pricing starts at $3/month and standard pricing starts at $10/month, both of which include access to GLM-5.1 and the lighter GLM-5.1-Air variant.

Export the key to your shell so the later commands can pick it up:

export GLM_API_KEY="your-z-ai-key-here"

Step 2: Register GLM with OpenClaw

OpenClaw supports multiple providers side by side. You are not removing Claude — you are adding GLM as a second option so you can switch per agent or roll back instantly.

openclaw provider add glm \
  --api-key $GLM_API_KEY \
  --base-url https://api.z.ai/api/coding/paas/v4

That URL matters — it points at Z.ai's coding platform endpoint, not the consumer chat endpoint. The consumer endpoint exists and it will authenticate with the same key, but tool-calling and agent workflows behave differently there. More on that in the gotchas section.

Step 3: Swap the Model in Your SOUL.md

Open the SOUL.md of the agent you want to migrate. Find the model line and change it. That is almost the entire migration.

  Name: Echo
  Role: Content Writer
- Model: claude/sonnet-4-6
+ Model: glm/glm-5.1
  Tools: web-search, file-read, file-write
  Memory: memory/context.md

For cost-sensitive agents — a quick classifier, a summary job, a daily digest — consider glm/glm-5.1-air instead. It is a lighter variant on the same provider, routes through the same endpoint, and costs less per call. Keep the full glm-5.1 for reasoning and code-heavy agents where the extra capacity pays for itself.

Step 4: Run Your Existing Test Suite

Do not skip this. Send the same test prompt you used when you first built the agent on Claude. If you do not have one, write one — pick a request that exercises the agent's main tool path.

openclaw agent --agent echo --message "Write a 200-word intro for a post about GLM-5.1 migration. Use web-search to find the Z.ai docs URL."

Compare output against your Claude baseline. You are checking three things: does the agent follow instructions, does it call tools correctly, and does the output quality match what you are used to. If any of those fail, the gotchas section below is where you start looking.

Step 5: Monitor the First 24 Hours

A single smoke test is not enough for agents that run on a schedule. Let the migrated agent run for a full day under normal load, then look at three signals:

The 5 Gotchas

These are the migration-specific pain points. None are deal-breakers, but they will bite you if you do not know about them upfront.

Cost Example: A Content Writer Running 50 Tasks/Day

One concrete scenario. A content-writer agent kicks off 50 tasks per day — short drafts, summaries, outline generation. Numbers below are indicative, not a price quote. Your actual mileage depends on prompt length, output length, and tool usage. The point is the shape of the savings.

The absolute dollar numbers are less interesting than the ratio. For agents that run coding, content, or summarization workloads at steady volume, GLM-5.1 consistently lands at a fraction of the Anthropic bill — that is what makes the migration worth the 10 minutes.

Next Steps

Frequently Asked Questions