GLM Models for GitHub Copilot Chat

Bring Z.AI's GLM models into GitHub Copilot Chat with your own API key (BYOK) — GLM-5.3, the default 1M-context Coding Plan model, multimodal GLM-5.3-Flash, and a curated lineup (GLM-5.2, GLM-5.1, GLM-5, GLM-4.7, GLM-4.5 Air). No new sidebar or chat UI: the models appear in the picker you already use, with image input, agent mode, tool calling, and thinking through Copilot's native provider path.

Unofficial, community-built extension. Not affiliated with, endorsed by, or sponsored by Zhipu AI, Z.AI, GitHub, or Microsoft. "GLM", "Copilot", and "Visual Studio Code" are trademarks of their respective owners. You bring your own GLM API key and pay your own usage.

Features

• GLM-5.3 by default, right in the picker. The Coding Plan model has a 1M-token context window and step-by-step thinking that streams live into Copilot's native thinking UI. Its per-model Thinking Effort control offers Low / High / Max, defaults to Max, and always keeps thinking enabled. Switch models mid-chat without losing history.

• Powers Copilot up, doesn't replace it. GLM models appear alongside GPT and Claude. Because the extension uses Copilot's native Language Model Provider API, agent mode and tool calling keep working as usual.

• Dual API. Use your GLM Coding Plan subscription or the pay-as-you-go Standard API — each available International (z.ai) or Mainland China (bigmodel.cn). See Coding Plan vs Standard API.

• Live usage & balance tracking. A status-bar readout plus a full GLM: Show Usage Details panel. Coding Plan shows session (5-hour) and weekly (7-day) token limits, monthly web searches, and reset countdowns. Standard API shows cash balance and token resource packages. The status bar turns red when quota hits 100% or balance reaches 0. Works on both International (z.ai) and Mainland China (bigmodel.cn) endpoints for both API modes; no baseUrl override.

• Keys stay in your OS keychain by default. GLM: Set API Key stores your key via VS Code SecretStorage (macOS, Windows, Linux). The extension also honors a settings fallback for CI or automation, so do not put real keys in workspace settings.
• Zero runtime dependencies. Pure VS Code API and Node.js built-ins — no Python, Docker, MCP server, or local package installation.
• Add any model. Newly released, fine-tuned, or proxy-hosted GLM models via glm-copilot.customModels.
• See images on every model. GLM-5.3-Flash accepts pasted images directly. For text-only models, the extension asks Flash for a neutral description first and supplies it as untrusted visual context. No separate server or key is required. See Image input.

Getting Started

Prerequisites

• VS Code 1.127 or later
• An active GitHub Copilot subscription (Free, Pro, or Enterprise)
• A GLM API key from z.ai or bigmodel.cn, or a GLM Coding Plan subscription

Installation

Install from the VS Code Marketplace, or search "GLM Models for GitHub Copilot Chat" in the Extensions panel (Cmd/Ctrl + Shift + X):

code --install-extension yijiazhen-qi.glm-for-github-copilot-chat

Upgrading from an older Marketplace listing? Uninstall it first — the old and new IDs can both register the same glm-copilot.* commands and settings:

code --uninstall-extension YijiazhenQi.glm-for-copilot-chat
code --install-extension yijiazhen-qi.glm-for-github-copilot-chat

Usage

1. GLM: Set API Key (Command Palette, Cmd/Ctrl + Shift + P) → paste your key. GLM key format is {id}.{secret}.
2. (Optional) GLM: Open Settings to choose your API mode and region.
3. Open Copilot Chat and start with GLM-5.3, or pick another available GLM model.

Use GLM: Set API Key or GLM: Clear API Key to update or remove the key later.

Models

Model	Tier	Context	Max Output	Available on official endpoints	Images	Tools	Thinking
GLM-5.3	Default coding model	1M	128K	Coding Plan only	Via Flash	Yes	Always on (Low / High / Max)
GLM-5.3-Flash	Multimodal	1M	128K	Coding Plan + Standard	Native	Yes	Always on (Low / High / Max)
GLM-5.2	Flagship	1M	128K	Coding Plan + Standard	Via Flash	Yes	Yes (effort)
GLM-5.1	Prior flagship	200K	128K	Standard only	Via Flash	Yes	Yes
GLM-5	Prior flagship	200K	128K	Standard only	Via Flash	Yes	Yes
GLM-4.7	Fast coding	200K	128K	Coding Plan + Standard	Via Flash	Yes	Yes
GLM-4.5 Air	Lightweight	128K	96K	Coding Plan + Standard	Via Flash	Yes	Yes

Without a custom baseUrl, the picker filters built-in models by API Mode, so you never pick one the official endpoint can't serve. GLM-5.3 is currently Coding-Plan-only; GLM-5.3-Flash, GLM-5.2, GLM-4.7, and GLM-4.5 Air work on both; GLM-5 and GLM-5.1 are Standard-only. A custom baseUrl skips this official availability filter because the extension cannot infer the capabilities of a compatible endpoint. Custom models are always included and replace built-in definitions with the same id. Need a model not listed — newer, older (GLM-4.6), or proxy-hosted? Add it with glm-copilot.customModels.

For new conversations, the extension contributes GLM-5.3 as VS Code's default. An explicit user or organization chat.defaultModel setting takes precedence. GLM-5.3 is omitted from the official Standard API picker, where you must select another available model.

Settings

Setting	Default	Description
glm-copilot.apiMode	coding-plan	Which GLM API to use: coding-plan or standard. See below.
glm-copilot.region	international	Server region for both chat API modes and Flash image analysis: international (z.ai) or china (bigmodel.cn). A custom baseUrl overrides it for all model requests.
glm-copilot.baseUrl	(empty)	Override the GLM API base URL. Overrides apiMode and region, including Flash image fallback, and skips official API-mode model filtering because compatible endpoint capabilities cannot be inferred. Images are never silently sent to a different endpoint.
glm-copilot.maxTokens	0	Maximum output tokens per request. 0 means no explicit limit (uses API default).
glm-copilot.maxRetries	3	Automatic retries for transient chat failures (HTTP 429/5xx), not counting the first attempt. 0 disables retries (fail fast). Range 0–10. Backoff honors the server's Retry-After.
glm-copilot.thinking	enabled	Step-by-step reasoning for models without a per-model Thinking Effort picker: enabled (higher quality) or disabled (faster). GLM-5.2 uses None / High / Max; GLM-5.3 requires thinking and uses Low / High / Max, defaulting to Max.
glm-copilot.visionPrompt	(empty)	Instruction sent to GLM-5.3-Flash when a text-only model needs image analysis. Empty uses the built-in neutral description prompt. Changing it invalidates the in-memory analysis cache.
glm-copilot.customModels	[]	Add your own models. Array of model id strings or objects: { id, name?, maxInputTokens?, maxOutputTokens?, toolCalling?, thinking?, nativeImageInput? }. nativeImageInput defaults to false.
glm-copilot.modelIdOverrides	{}	Remap a built-in model's API id (keys = picker id, values = id sent to the API). Use for regional endpoints or proxies with different names.
glm-copilot.debugLogging	false	Write verbose debug logs to the GLM output channel. View with GLM: Show Logs.
glm-copilot.usageRefreshIntervalMinutes	5	How often (in minutes) to refresh the GLM usage status bar. Minimum 1. Shows Coding Plan quota or Standard API balance for both z.ai and bigmodel.cn regions. Only when no baseUrl override.
glm-copilot.showUsageStatusBar	true	Show the GLM usage status-bar item. Coding Plan quota or Standard API balance, both z.ai and bigmodel.cn regions. Only when no baseUrl override.

Coding Plan vs Standard API

Coding Plan requires a GLM Coding Plan subscription — best for teams or high-volume coding. Standard API is pay-as-you-go via the GLM Open Platform. The endpoint follows your region either way.

If the Usage panel cannot find usable Coding Plan quota for the current key, or the session/weekly token quota is exhausted, it offers Check Standard API. The extension checks the current key's Standard balance only after you click that action. A positive cash or token-package balance opens a pay-as-you-go confirmation; only Switch to Standard API changes glm-copilot.apiMode. Dismissing the confirmation or receiving an unavailable, unauthorized, empty, or zero balance changes neither the mode nor the stored key. The model picker then refreshes for Standard availability without selecting a replacement model automatically. Monthly web-search exhaustion alone does not offer this recovery, and it is unavailable with a custom baseUrl.

Mode	Region	Endpoint	Get a key
Coding Plan	International	https://api.z.ai/api/coding/paas/v4	z.ai/manage-apikey/subscription
Coding Plan	Mainland China	https://open.bigmodel.cn/api/coding/paas/v4	bigmodel.cn/coding-plan
Standard	International	https://api.z.ai/api/paas/v4	z.ai/manage-apikey/apikey-list
Standard	Mainland China	https://open.bigmodel.cn/api/paas/v4	open.bigmodel.cn

Full API documentation: docs.z.ai.

GLM-5.3 is documented for Coding Plan on both the Z.AI and BigModel endpoints. The current Z.AI Standard API pricing catalog does not include it. BigModel's model overview lists GLM-5.3, but its model page says the model API is not yet available. This extension therefore does not expose GLM-5.3 on the official Standard endpoints yet; a compatible custom baseUrl may serve it.

GLM-5.3-Flash is documented for Coding Plan and Standard use by both Z.AI and BigModel.

Usage details rely on regional usage endpoints (api.z.ai for International, open.bigmodel.cn for Mainland China) that are not part of the public chat-completions API. If those endpoints are unavailable or change, the extension degrades to a status message instead of blocking chat.

Image input

Paste or attach PNG and JPEG images directly in Copilot Chat. No MCP server, local package, toggle, or separate Vision key is required.

• Native Flash path — GLM-5.3-Flash receives text and images in their original order as multimodal content.
• Text-model fallback — for other models, the extension sends each image group to GLM-5.3-Flash first, then wraps the returned description as untrusted visual data for the selected model. Text found in an image is context, never authorization or a tool instruction.
• Same endpoint and key — both requests use the active baseUrl and chat API key. A custom endpoint must serve a compatible glm-5.3-flash model; the extension never reroutes images to Z.AI or BigModel behind your back.
• Validated and cached — up to 16 PNG/JPEG images are accepted, with a 5 MB limit per image. Descriptions are cached in memory using image content, endpoint, resolved model id, and prompt.
• Visible progress, graceful failure — Flash fallback reports progress. If it is unavailable, the selected text model still receives the remaining content plus an unavailable marker. Cancelling stops image analysis and prevents the main request.

Customize fallback analysis with GLM: Edit Flash Image Analysis Prompt or glm-copilot.visionPrompt.

Commands

Command	Description
GLM: Set API Key	Set or update your GLM API key
GLM: Get API Key	Open the key management page for your selected API mode
GLM: Clear API Key	Remove your stored API key
GLM: Open Settings	Open the extension settings
GLM: Show Logs	Open the GLM output channel
GLM: Refresh Usage	Refresh GLM usage/balance now (Coding Plan quota or Standard API balance; both z.ai and bigmodel.cn)
GLM: Show Usage Details	Open the GLM usage panel (Coding Plan quota or Standard API balance; both z.ai and bigmodel.cn)
GLM: Edit Flash Image Analysis Prompt	Open the multiline setting used by text-model image fallback

Frequently asked questions

Is this an official GLM or GitHub extension?

No. Unofficial, community-built, open source — not affiliated with Zhipu AI, Z.AI, GitHub, or Microsoft. It just lets you use your own GLM API key inside Copilot Chat.

Do I still need a GitHub Copilot subscription?

Yes. This adds GLM models to Copilot Chat; it doesn't replace Copilot. You need an active Copilot subscription (Free, Pro, or Enterprise) and your own GLM API key.

Where does my API key go?

GLM: Set API Key stores the key in VS Code SecretStorage (the OS keychain on macOS, Windows, Linux). Chat and Flash image fallback send it only to the configured GLM endpoint over HTTPS. A settings fallback exists for CI or automation, but avoid putting real keys in settings.json, especially workspace settings that could be committed.

Can I use a proxy or self-hosted endpoint?

Yes. Set glm-copilot.baseUrl to an OpenAI-compatible endpoint; it overrides apiMode and region for chat and image fallback. Text-only models require that endpoint to expose a compatible glm-5.3-flash model, or a mapped id through modelIdOverrides.

Is GLM-4.6 still supported?

GLM-4.6 was superseded by GLM-4.7 and the GLM-5 series in v0.2.0. Add it with glm-copilot.customModels if your account still serves it.

Contributing

Contributions welcome — see the contributing guide and Code of Conduct. All PRs require code-owner review and are never auto-merged.

• Bug? Open a report · Feature? Request it
• Help? Support or Discussions · Security? Policy

Changelog

See CHANGELOG.md.

License

MIT © GLM Models for GitHub Copilot Chat contributors