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What Is GLM-5? Z.AI’s Model, Capabilities, and API Considerations

Learn what GLM-5 is, what Z.AI says it can do, how it differs from GLM-5.1 and GLM-5V-Turbo, and what to verify before using it in production.

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GLM-5 is a text-based foundation model from Z.AI, designed for complex system engineering and long-range agent tasks. Z.AI describes it as a model for planning and carrying out multi-step work, including coding and tool use. Its documentation lists a 200K-token context length and up to 128K output tokens. These are published model specifications; a provider may expose different limits or features. (Z.AI model documentation)

GLM-5 is a specific model name, not a generic API standard. Z.AI describes GLM-5.1 as a later flagship model. Do not assume that specifications or API instructions for GLM-5.1—or for the separately documented multimodal model GLM-5V-Turbo—also apply to GLM-5. (Z.AI GLM-5.1 documentation; Z.AI GLM-5V-Turbo documentation)

What is GLM-5 designed to do?

Z.AI positions GLM-5 for “Agentic Engineering”: complex systems work and longer-running tasks involving multiple steps. Its documentation lists coding, agent tasks with tool invocation, structured output, text extraction, translation, and long-form writing among its use cases. These are vendor descriptions of intended capabilities, not guarantees of performance on a particular task or provider. (Z.AI model documentation)

As one benchmark example, Z.AI reports that GLM-5 finished Vending Bench 2 with a $4,432 account balance. The benchmark asks a model to run a simulated vending-machine business over a one-year horizon, with the ending balance used as its score. This result speaks to that evaluation; it does not show that the model can reliably manage a real business or production system. (Z.AI GLM-5 release post; Vending-Bench 2 description)

A reasonable workload to evaluate: multi-step coding, project planning, or tasks where the model must use tools and maintain a goal across several stages. A key limitation when interpreting claims: vendor capability descriptions and benchmark results do not establish how reliably the model will handle your own data, workflow, or failure cases. Test those directly before relying on it.

GLM-5 vs. GLM-5.1 and GLM-5V-Turbo

These are distinct model names; do not treat their specifications or API instructions as interchangeable.

  • GLM-5 is the model described in this guide. Z.AI’s release post reports 744 billion total parameters and 40 billion active parameters, and says the weights were released under the MIT License. (Z.AI GLM-5 release post)
  • GLM-5.1 is a later model. Z.AI describes it separately and lists its own capabilities and limits. Those details apply to GLM-5.1, not GLM-5. (Z.AI GLM-5.1 documentation)
  • GLM-5V-Turbo is a separately named multimodal coding model. Z.AI’s documentation for it describes image, video, text, and file inputs; those are not specifications for GLM-5. (Z.AI GLM-5V-Turbo documentation)

Some third-party coverage rounds GLM-5’s parameter count to about 745 billion. Z.AI’s release post gives 744 billion total and 40 billion active parameters; for technical or commercial decisions, prefer the official model-specific information over rounded secondary figures. (Z.AI GLM-5 release post; WaveSpeed GLM-5 article)

Accessing GLM-5 through a production API

Z.AI’s GLM-5 release post says the model is available on its developer platform. Z.AI documents a general chat-completions route at https://api.z.ai/api/paas/v4/chat/completions, but the current example returned in that documentation uses the model ID glm-5.3, not glm-5. This guide has not verified a current GLM-5-specific request ID or confirmed that GLM-5 is currently enabled for a particular account. Do not infer those details from the general endpoint alone. (Z.AI GLM-5 release post; Z.AI chat-completions documentation)

Before launch, verify these details with the provider you will actually use:

  1. Exact model ID and version: confirm that requests target GLM-5—not GLM-5.1 or GLM-5V-Turbo—and that the model is available to your account.
  2. Endpoint and authentication: confirm the applicable base URL, route, API-key type, and required headers. Z.AI notes that keys for different products may not be interchangeable. (Z.AI API introduction)
  3. Request and response behavior: check supported message formats, tool calling, structured output, streaming, errors, and token-usage fields.
  4. Operational terms: confirm context and output limits, rate limits, availability terms, and data-handling conditions.
  5. Price: check the provider’s current GLM-5 rates and billing units. Do not assume a third-party listing or a rate for a newer model applies to GLM-5.

The GLM-5-specific request identifier and current production terms should be confirmed with your selected provider. Do not copy an example for GLM-5.1, GLM-5.3, or GLM-5V-Turbo and assume it will work for GLM-5.

How to decide whether GLM-5 fits your workload

Run a small evaluation using representative tasks before choosing GLM-5 for production. Include typical inputs, difficult edge cases, and expected tool use. Score outputs against your requirements for correctness, completeness, format adherence, and safe failure behavior; also record latency and usage cost with the provider and settings you intend to deploy.

Compare those results with your current model or a relevant alternative. GLM-5’s stated focus makes it a candidate to test for complex, multi-step engineering work, but the right choice depends on measured results and provider terms—not the model description alone. Confirm current availability, pricing, and limits before budgeting or rollout.

Sources

GLM-5 - Overview - Z.AI Developer Documentation

GLM-5: From Vibe Coding to Agentic Engineering - Z.AI

Vending-Bench 2 - Andon Labs

GLM-5.1 - Overview - Z.AI Developer Documentation

GLM-5V-Turbo - Overview - Z.AI Developer Documentation

What Is GLM-5? Architecture, Speed & API Access - WaveSpeed

Chat Completion - Z.AI Developer Documentation

Introduction - Z.AI Developer Documentation

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