# GLM-5.3-FlashX-Legal

GLM-5.3-FlashX-Legal is Z.AI's legal-domain variant of GLM-5.3-FlashX, a natively multimodal model given additional legal mid-training and post-training. It targets legal research, contract review, cross-document checks and drafting, typically inside agent setups connected to legal data and document-editing tools. Its published context window is 1,000,000 tokens. The advertised input rate is $0.37 per million input tokens. The advertised output rate is $1.25 per million output tokens.

- Model identifier: ` zai/glm-5.3-flashx-legal `
- Creator: Z.AI
- Providers: Z.AI
- Model type: Text generation
- Canonical model page: [GLM-5.3-FlashX-Legal](<https://impossibl.com/zai/glm-5.3-flashx-legal>)
- API availability: Listed as serving through Impossibl.
- Creator release date: 2026-10-29

## Providers

Z.AI hosts GLM-5.3-FlashX-Legal. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

| Provider | Endpoint location | Routes | Verified context window | Tool calling |
| --- | --- | --- | --- | --- |
| Z.AI | Not specified | 1 | Not verified | Not verified |

The model price applies whichever provider serves the request. Endpoint locations do not guarantee inference residency.

## Specs and Capabilities

- Context window: 1,000,000 tokens
- Maximum output tokens: Not published in the public catalog; this is separate from the context window.
- Inputs: text, image
- Outputs: text
- Tool calling: Not published

## API access

Use ` zai/glm-5.3-flashx-legal ` as the model identifier through the Impossibl API.

Published API endpoints:

- ` /v1/chat/completions `

[API quickstart](<https://impossibl.com/docs/agent-quickstart>) · [Models and billing documentation](<https://impossibl.com/docs/models>)

## Published API prices

All rates are in USD. An unpublished rate is unknown, not zero. Workspace-specific pricing, taxes, balance-purchase fees, billing adjustments, and tool charges can affect the amount paid.

| Usage | Published base rate | Billing unit |
| --- | --- | --- |
| Input | $0.37 | per million input tokens |
| Output | $1.25 | per million output tokens |
| Cache read | $0.075 | per million cached input tokens |
| Cache write (default retention) | Not published | per million tokens |
| Cache write (one-hour retention) | Not published | per million tokens |
| Audio input | Not published | per million audio input tokens |

## Availability and retirement

The model is listed as serving. No retirement is announced in the current public catalog.

## Frequently asked questions

### What is GLM-5.3-FlashX-Legal?

GLM-5.3-FlashX-Legal is Z.AI's legal-domain variant of GLM-5.3-FlashX, a natively multimodal model given additional legal mid-training and post-training. It targets legal research, contract review, cross-document checks and drafting, typically inside agent setups connected to legal data and document-editing tools.

Sources: [Z.AI GLM-5.3-Flash/FlashX/FlashX-Legal documentation](<https://docs.z.ai/guides/vlm/glm-5.3-flash>); [AutoClaw: GLM-5.3-flashX-Legal is now available](<https://autoclaw.z.ai/blog/model/GLM-5.3-flashX-Legal/>); [GLM-Legal: Advancing Agentic Legal Intelligence](<https://autoclaw.z.ai/blog/model/GLM-Legal/>); [OpenRouter GLM 5.3 FlashX Legal](<https://openrouter.ai/z-ai/glm-5.3-flashx-legal>)

### How much does GLM-5.3-FlashX-Legal cost?

GLM-5.3-FlashX-Legal costs $0.37 per million input tokens and $1.25 per million output tokens through the Impossibl API. Cache reads cost $0.075 per million tokens. All rates are in USD.

### What is the context length of GLM-5.3-FlashX-Legal?

GLM-5.3-FlashX-Legal has a 1,000,000-token context window through the Impossibl API.

### What inputs and outputs does GLM-5.3-FlashX-Legal support?

GLM-5.3-FlashX-Legal accepts text and image as input. GLM-5.3-FlashX-Legal returns text.

### How do I use GLM-5.3-FlashX-Legal through an API?

GLM-5.3-FlashX-Legal is available through the Impossibl API. Use zai/glm-5.3-flashx-legal as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

### When was GLM-5.3-FlashX-Legal released?

Z.AI released GLM-5.3-FlashX-Legal on October 29, 2026.

Sources: [Creator release announcement](<https://autoclaw.z.ai/blog/model/GLM-5.3-flashX-Legal/>)

## Sources and related links

Prices, limits, capabilities, endpoints, and availability come from the public Impossibl catalog. Creator documentation supplies descriptions and release dates where available; it does not override the published API offering.

- [Public Impossibl model catalog](<https://api.impossibl.com/v1/models>)
- [Full model directory as JSON](<https://impossibl.com/models.json>)
- [GLM-5.3-FlashX-Legal: model details and pricing](<https://impossibl.com/zai/glm-5.3-flashx-legal>)
- [Model directory](<https://impossibl.com/models>)
- [Z.AI GLM-5.3-Flash/FlashX/FlashX-Legal documentation](<https://docs.z.ai/guides/vlm/glm-5.3-flash>)
- [AutoClaw: GLM-5.3-flashX-Legal is now available](<https://autoclaw.z.ai/blog/model/GLM-5.3-flashX-Legal/>)
- [GLM-Legal: Advancing Agentic Legal Intelligence](<https://autoclaw.z.ai/blog/model/GLM-Legal/>)
- [OpenRouter GLM 5.3 FlashX Legal](<https://openrouter.ai/z-ai/glm-5.3-flashx-legal>)