How long can GLM 5.1 work on a single task?

Over eight hours of continuous autonomous operation. It plans, executes, tests, and iterates on its own output throughout that window.

How does GLM 5.1 differ from GLM-5?

GLM-5 introduced multiple thinking modes and agentic workflows for general-purpose reasoning. GLM 5.1 builds on that foundation with a specific focus on long-horizon coding tasks, sustaining autonomous operation for hours rather than minutes.

What is the pricing for GLM 5.1?

Check the pricing panel on this page for today's numbers. AI Gateway tracks rates across every provider that serves GLM 5.1.

How do I access GLM 5.1 through AI Gateway?

Use the `zai/glm-5.1` model identifier with your AI Gateway API key. No separate Z.AI account is needed. BYOK is also supported.

Z.AI

GLM 5.1

GLM 5.1 advances Z.AI's GLM-5 generation with a focus on long-horizon autonomous coding. It can work independently on a single task for over eight hours, planning, executing, and iterating until it delivers engineering-grade results. Your use is subject to Z.AI's Terms & Privacy Policies.

View API reference

Input and output price: Prices from: Input $1.40, Output $4.40, Per 1M tokens
24h uptime: Loading AI Gateway uptime

Get API key Read the docs

import { streamText } from 'ai'

const result = streamText({
  model: 'zai/glm-5.1',
  prompt: 'Why is the sky blue?'
})

Read docs

Overview Playground Providers Uptime Status Throughput Latency API Similar About FAQ

Copy link to headingPlayground

Try out GLM 5.1 by Z.AI. Usage is billed to your team at API rates. Free users (those who haven't made a payment) get $5 of credits every 30 days.

GLM 5.1

Copy link to headingProviders

Route requests across multiple providers. Copy a provider slug to set your preference. Visit the docs for more info. Using a provider means you agree to their terms, listed under Legal.

Checking availability for your team

Provider

Context	Max Output	Weight Format	Latency	Throughput	Cache Hit	Input	Output	Cache	Search	Capabilities	ZDR	No Training	Free AI Gateway Credit	Release Date

Z.AI

Legal:Terms•Privacy

203K

64K

—

6.1 s

47 tps

80%

$1.40/M

$4.40/M

Read$0.26/M

—

04/07/2026

Novita AI

Legal:Terms•Privacy

205K

131K

fp8

1.4 s

155 tps

—

$1.38/M

$4.40/M

Read$0.26/M

—

04/07/2026

Getting started

Call GLM 5.1 through AI Gateway with the AI SDK generateText and streamText functions, or through the OpenAI Chat Completions, OpenAI Responses, and Anthropic Messages APIs by changing the base URL. AI Gateway authenticates the request and routes it to an available provider.

Install the AI SDK (pnpm add ai dotenv), create an API key from the API Keys page, and set it as AI_GATEWAY_API_KEY in your environment. Full setup is covered in the text generation quickstart.

index.ts

import { generateText } from 'ai';
import 'dotenv/config';

async function main() {
  const result = await generateText({
    model: 'zai/glm-5.1',
    prompt: 'Why is the sky blue?',
  });

  console.log(result.text);
}

main().catch(console.error);

Top-level parameters

The same GLM 5.1 request in each API format AI Gateway supports.

top-level-params.ts

import { generateText } from 'ai';
import 'dotenv/config';

async function main() {
  const result = await generateText({
    model: 'zai/glm-5.1',
    system: 'You are a concise technical assistant.',
    prompt: 'Summarize the tradeoffs between static generation and SSR.',
    maxOutputTokens: 1024,
  });

  console.log(result.text);
}

main().catch(console.error);

Standard parameters like prompt, messages, temperature, and tools work as documented in the AI SDK docs. These are the parameters with model-specific behavior.

Parameter	Type	Required	Description
`model`	`string`	Yes	Model ID in the form `creator/model`, e.g. `zai/glm-5.1`. AI Gateway routes the request to an available provider.
`maxOutputTokens`	`number`	No	Hard cap on generated tokens. GLM 5.1 supports up to `131,072` output tokens. Reasoning tokens count toward this limit.
`reasoning`	`'provider-default' \| 'none' \| 'minimal' \| 'low' \| 'medium' \| 'high' \| 'xhigh'`	No	Provider-agnostic reasoning effort, available in AI SDK 7 or later. Maps to the provider’s native reasoning configuration; reasoning settings under `providerOptions` take precedence when both are set. See the Reasoning section below.
`providerOptions`	`Record<string, JSONValue>`	No	AI Gateway routing options under `gateway`, plus any provider-native options under the provider’s own namespace — see the table below.

Input limits

Input	Formats	Sources	Max count	Max size	Limits
Text	—	—	—	—	Prompt and response share the 205K-token context window

Provider options

Set AI Gateway routing options under providerOptions.gateway. For provider-specific options, pass them under the provider’s namespace as documented by the AI SDK.

Learn more in the AI SDK provider docs.

provider-options.ts

import { generateText } from 'ai';
import 'dotenv/config';

async function main() {
  const result = await generateText({
    model: 'zai/glm-5.1',
    prompt: 'Why is the sky blue?',
    providerOptions: {
      gateway: {
        only: ['zai', 'novita'],
      },
    },
  });

  console.log(result.text);
}

main().catch(console.error);

These AI Gateway routing options apply to every model. Provider-specific options pass through under the provider’s own namespace (for example providerOptions.anthropic) exactly as documented by the AI SDK.

Parameter	Type	Required	Description
`providerOptions.gateway.only`	`string[]`	No	Restrict routing to these provider slugs. Requests fail over only within the listed providers.
`providerOptions.gateway.order`	`string[]`	No	Preferred provider order. Listed providers are tried first; unlisted providers remain available as fallbacks.
`providerOptions.gateway.sort`	`'cost' \| 'ttft' \| 'tps'`	No	Rank candidate providers by price, time to first token, or tokens per second instead of the default routing order.
`providerOptions.gateway.zeroDataRetention`	`boolean`	No	Route only to providers with a zero-data-retention policy for this model.

Routing across providers

AI Gateway serves the same model through multiple providers and fails over automatically. order expresses a preference while keeping every provider eligible; only is a hard allowlist — if none of the listed providers are available the request fails instead of falling back.

Options under a provider's own namespace (for example providerOptions.anthropic) are forwarded to that provider with the request. Providers ignore option namespaces that don't apply to them, so it is safe to set provider options alongside gateway routing options.

Reasoning

AI Gateway bridges reasoning across every API format. The AI SDK exposes a provider-agnostic top-level reasoning level (none, minimal, low, medium, high, or xhigh); the Chat Completions and Responses formats take the same effort under reasoning.effort; and the Anthropic Messages format uses a native thinking token budget. Whichever you send, the gateway maps it to the target model’s native configuration, converting between effort levels and token budgets as needed. Reasoning-related settings under providerOptions take full precedence over the top-level reasoning value and are never merged. Reasoning tokens typically count toward your output-token usage, though how they’re reported and billed varies by provider.

Learn more in the AI Gateway reasoning guide.

reasoning.ts

import { generateText } from 'ai';
import 'dotenv/config';

async function main() {
  const result = await generateText({
    model: 'zai/glm-5.1',
    prompt: 'Explain the Monty Hall problem step by step.',
    reasoning: 'high',
  });

  console.log(result.text);
}

main().catch(console.error);

Tool calling

Expose tools the model can call. Define each tool’s inputs with a Zod schema.

tool-calling.ts

import { generateText, tool } from 'ai';
import { z } from 'zod';
import 'dotenv/config';

async function main() {
  const result = await generateText({
    model: 'zai/glm-5.1',
    prompt: 'What is the weather in San Francisco?',
    tools: {
      getWeather: tool({
        description: 'Get the current weather for a location',
        inputSchema: z.object({ location: z.string() }),
        execute: async ({ location }) => ({ location, temperatureC: 18 }),
      }),
    },
  });

  console.log(result.text);
}

main().catch(console.error);

Copy link to headingMore models by Z.AI

Model

Context	Latency	Throughput	Input	Output	Cache	Search	Capabilities	Providers	ZDR	No Training	Free AI Gateway Credit	Release Date

zai/glm-5.3-flashx

2.3 s

163 tps

$0.37/M

$1.25/M

Read$0.08/M

—

09/18/2026

zai/glm-5.3-fast

0.6 s

405 tps

$2.10/M

$6.60/M

Read$0.21/M

—

09/02/2026

zai/glm-5.3-flash

0.2 s

460 tps

$0.03/M

$0.25/M

Read$0.0051/M

—

+17

08/26/2026

zai/glm-5.3

0.2 s

390 tps

$0.08/M+1 more

$2.40/M+1 more

Read$0.05/M

Write$2.10/M

—

+19

08/18/2026

zai/glm-5.2

0.2 s

620 tps

$0.19/M+1 more

$1.80/M+1 more

Read$0.11/M

—

+12

06/16/2026

zai/glm-5

203K

0.2 s

163 tps

$1/M

$3.20/M

Read$0.20/M

—

02/12/2026

Copy link to headingAbout GLM 5.1

GLM 5.1 builds on the GLM-5 generation with a significant jump in coding capability, released April 7, 2026. Where GLM-5 introduced multiple thinking modes and agentic workflows, GLM 5.1 pushes the autonomy envelope: it sustains focus on one task for over eight hours, continuously planning, writing code, running tests, and improving its own output without human intervention.

The model targets long-horizon tasks that earlier models struggle with. Multi-file refactors, end-to-end feature implementation, and large-scale codebase migrations benefit from the extended autonomous execution window. Rather than handing back partial results for human review at each step, GLM 5.1 completes the full loop and delivers finished, tested code.

GLM 5.1 supports a context window of 204.8K tokens and max output of 131.1K tokens. Through AI Gateway, it shares the same unified API, built-in observability, and provider routing as other Z.AI models.

Copy link to headingWhat To Consider When Choosing a Provider

Configuration: GLM 5.1 excels when given a well-defined task with clear acceptance criteria. Provide a detailed specification, relevant file paths, and expected behavior so the model can plan its autonomous execution effectively.
Configuration: Tasks running for hours consume tokens proportionally. Monitor usage through AI Gateway's observability tools and set budget limits for extended runs.
Configuration: Despite autonomous self-correction, review the final output before merging into production. Treat GLM 5.1 as a thorough junior engineer who still needs a code review.
Zero Data Retention: Zero Data Retention is offered on a per-provider and model basis. See the documentation for details.
Authentication: AI Gateway authenticates requests using an API key or OIDC token. You do not need to manage provider credentials directly.

Copy link to headingWhen to Use GLM 5.1

Best for

Large-scale refactors: Dozens of files where sustained context and iterative testing matter
End-to-end feature implementation: Spec to tested, working code with minimal human checkpoints
Codebase migrations: Hours of methodical file-by-file changes
Complex bug investigations: The model autonomously traces root causes across a large codebase
Autonomous coding agents: A model capable of multi-hour independent operation

Consider alternatives when

Short-horizon tasks: GLM-5 or GLM-5-Turbo handle coding tasks completing in minutes at lower cost
Vision or multimodal input: GLM-5V-Turbo combines coding with screenshot and GUI understanding
Interactive pair programming: GLM-4.7-Flash provides fast responses for real-time back-and-forth workflows
Budget-constrained workloads: GLM-5-Turbo offers GLM-5-class capability at reduced per-token cost for shorter tasks

Copy link to headingConclusion

GLM 5.1 targets the gap between short-burst coding assistance and fully autonomous software engineering. For tasks that take hours of sustained, methodical work, it delivers complete results where shorter-context models would lose coherence or require repeated human intervention.

Copy link to headingFrequently Asked Questions

How long can GLM 5.1 work on a single task?
Over eight hours of continuous autonomous operation. It plans, executes, tests, and iterates on its own output throughout that window.
How does GLM 5.1 differ from GLM-5?
GLM-5 introduced multiple thinking modes and agentic workflows for general-purpose reasoning. GLM 5.1 builds on that foundation with a specific focus on long-horizon coding tasks, sustaining autonomous operation for hours rather than minutes.
What is the context window for GLM 5.1?
204.8K tokens.
What is the pricing for GLM 5.1?
Check the pricing panel on this page for today's numbers. AI Gateway tracks rates across every provider that serves GLM 5.1.
How do I access GLM 5.1 through AI Gateway?
Use the zai/glm-5.1 model identifier with your AI Gateway API key. No separate Z.AI account is needed. BYOK is also supported.

GLM 5.1

Copy link to headingPlayground

Copy link to headingProviders

Copy link to headingUptime24 hours

Copy link to headingThroughput24 hours

Copy link to headingLatency24 hours

Getting started

Top-level parameters

Input limits

Provider options

Routing across providers

Reasoning

Tool calling

Copy link to headingMore models by Z.AI

Copy link to headingAbout GLM 5.1

Copy link to headingWhat To Consider When Choosing a Provider

Copy link to headingWhen to Use GLM 5.1

Best for

Consider alternatives when

Copy link to headingConclusion

Copy link to headingFrequently Asked Questions