glm-5.1

A mature flagship text model for complex programming and long-horizon tasks

GLM-5.1 is Zhipu AI's mature flagship text model, focused on complex programming, reasoning, and long-document analysis. It is suitable for breaking requirements into plans, revising code based on feedback, and advancing delivery across multi-turn tasks. This platform provides direct chat and managed session access, allowing you to choose self-managed history, function calling, or tool-enabled task workflows according to application needs.

ZhipuModel brand
ChatModel type
ChatTask capability

Specifications and interface features

Clarify capacity, input and output, and invocation methods before selecting a model.

Model type
Mature flagship text model in the GLM series
Input and output
Text input, text output; supports multi-turn conversations
Programming tasks
Code generation, complex engineering analysis, and feedback iteration
Tool collaboration
Function Calling; applications execute functions and return results
Structured delivery
Structured output; the direct endpoint provides JSON and JSON Schema format options
Interaction methods
The direct endpoint supports streaming responses; AI Chat v2 supports managed sessions and structured events

The model's text, programming, and tool collaboration capabilities should be understood separately from the session management, output formats, and execution features provided by each endpoint.

Core Capabilities

Learn what glm-5.1 can bring to your work.

From Requirements to Code Iteration

GLM-5.1 focuses not only on generating a piece of code, but also on planning and iteration in complex engineering tasks. After providing requirements, relevant implementations, and acceptance criteria, you can have it first break down the scope of changes and then propose an implementation plan; continue adding test failure information to drive revisions, rather than treating the initial response as the final deliverable.

Maintain Momentum in Long-Horizon Tasks

For tasks that require repeated analysis, execution, and adjustment, GLM-5.1 is well suited as the text-based decision-making core of an Agent. Organize goals, current state, and tool results into continuous context so it can determine the next action. Task progress should still be recorded by the application, so you can check whether the plan has drifted from the original constraints.

Bring Analysis into Business Workflows

Text conclusions can be combined with function calling and structured output: have the model propose functions that need to be called, or organize issues and recommendations in an agreed format. The direct entry point is suitable when applications need to control execution themselves; AI Chat v2 provides managed tool workflows and events, making it easier to display the task process and final answer.

Use Cases

Start with specific tasks to find where the model can make an impact.

Fix and Review Engineering Code

Provide relevant source code, error logs, dependency notes, and expected behavior, and ask GLM-5.1 to output issue identification, modification suggestions, and a test checklist. Bring actual test results back into the next round to continue refining the solution. This is suitable for defect handling and code review that require understanding constraints; delivered code still needs to be validated in a real environment.

Analyze Long Technical Materials

Organize requirements documents, interface specifications, or design records into text, and ask the model to extract constraints, identify contradictions, and produce a decision summary. You can analyze them section by section, then consolidate items requiring confirmation and implementation steps; retain section numbers so the team can trace back specific evidence instead of receiving only a general overview.

Build a Multi-Step Task Assistant

Define available tools for querying, reading, and business operations, allowing GLM-5.1 to choose actions based on the task and continue analyzing using execution results. When using AI Chat v2, you can continue tasks around a conversation ID and display progress through tool events; actions involving writes or publishing should have clear authorization and confirmation rules.

How to choose this model

Choose based on task complexity, input materials, and expected results.

Choose the mature flagship for complex text tasks

If the goal is complex reasoning, engineering code, or long-document analysis, GLM-5.1 is the mature flagship choice in the GLM series. GLM-5.3 is positioned for newer complex software engineering and Agent tasks; its capacity and reasoning settings should not be applied to GLM-5.1. Existing applications can compare results using the same requirements, logs, and acceptance criteria before deciding whether to switch.

Choose an endpoint based on control needs

If you need to maintain message history, parse function calls, and control response formats yourself, choose /glm/chat/completions. If you want managed multi-turn conversations, visibility into tool processes, or asynchronous tasks, choose /aichat2/conversations. Existing applications that only need to submit questions and receive answers can also continue using /aichat/conversations.

Get started

From a small-scale task to production integration.

01

Prepare tasks and materials

Define the goal, required inputs, and output requirements, using real business examples as a starting point.

02

Try it in the API playground

Open the trial page, confirm the parameters supported by this endpoint, then submit a small-scale task to review the results.

03

Integrate according to the API documentation

Keep the complete model ID, use the request format specified in the documentation, and confirm billing rules on the Pricing page.

Usage boundaries

Understand output quality and capability scope before production use.

  • GLM-5.1 should be used as a text model; do not treat image or audio fields in generic interfaces as its vision or speech capabilities. When processing documents, you can first provide the extracted body text; obtaining text with file-reading tools also does not mean the model can directly understand all attachment contents.
  • Long-running task capability does not mean that a normal conversational request will automatically run programs, modify repositories, or complete deployments. After the direct endpoint returns a function call, the application must execute it and return the result; tool execution should have permission boundaries, error handling, and necessary human confirmation.
  • Both long-document analysis and code modification depend on input completeness. Multi-turn tasks should retain key constraints and verified conclusions, and larger tasks should be accepted in stages; if a response ends due to length, check for missing parts before continuing to avoid delivering incomplete code directly.

Frequently Asked Questions

Answers to common questions about using glm-5.1.

Is GLM-5.1 better suited for programming or everyday Q&A?

It can be used for text-based Q&A, but its more valuable applications are complex programming, reasoning, and long-document analysis. Simple Q&A does not necessarily require a flagship model; when a task involves engineering constraints, error diagnosis, or multiple rounds of revision, GLM-5.1 is better suited to participate in analysis and execution.

How can I make GLM-5.1 more effective at fixing code?

Provide the relevant code, runtime environment, complete error information, and acceptance criteria at the same time. First have it explain the problem and scope of changes, then generate the implementation. Send back test results and continue revising; do not provide only “fix this error,” and do not omit dependencies and configurations that affect behavior.

Can GLM-5.1 automatically execute functions?

In the direct chat interface, the model returns the function name and parameters, the application is responsible for execution, and then sends the result back as a tool message. AI Chat v2 can use managed tool workflows, but specific actions are still constrained by tool availability and authorization; generated call information must not be treated as equivalent to successful execution.

Can GLM-5.1 search the web or read files?

These tasks can be organized through AI Chat v2's search, web scraping, and file-reading tools. They should be understood as tool-assisted text workflows, rather than built-in search or visual capabilities of the model. When analyzing attachments, confirm that the reading result includes the required body text and check whether key content has been omitted.

How can I continue multi-turn tasks when calling GLM-5.1?

For the direct interface, place historical messages in order in messages; for the managed session interface, use stateful and include the returned id. The former is suitable for controlling context yourself, while the latter is suitable for ongoing interaction. Regardless of the approach, it is recommended to clearly record the task objective, current progress, and items pending acceptance.

Model information · Updated: 2026-10-01. For calling parameters and billing rules, see the API and pricing sections.

Use glm-5.1 for your next task

Start with a clear objective and judge whether it suits your work based on real results.