Where does the bug appear (feature/product)? Cursor IDE Describe the Bug After updating the cursor and changing to GLM-5.1, and via a custom openapi key and url cursor agent could not see the outputs I am not getting this error on opencode or claude code. Auto etc is working correctly. Model is giving me this error I’m experiencing a persistent issue where none of my tool calls are returning any output. This seems to be a systemic problem with the tool execution environment. I can see the tool outputs there is nothing wrong there Steps to Reproduce Enter glm openapi key and url and just try to use it ide agents or model cannot see anything while there are outputs Operating System MacOS Version Information Version: 2.6.22 (Universal) VSCode Version: 1.105.1 Commit: c6285feaba0ad62603f7c22e72f0a170dc8415a0 Date: 2026-03-27T15:59:31.561Z (2 days ago) Build Type: Stable Release Track: Default Electron: 39.8.1 Chromium: 142.0.7444.265 Node.js: 22.22.1 V8: 14.2.231.22-electron.0 OS: Darwin arm64 25.1.0 For AI issues: which model did you use? GLM-5.1 Does this stop you from using Cursor Yes - Cursor is unusable

Hi Ozan, Thanks for your forum post! This looks most consistent with a compatibility gap in the current custom-provider path rather than anything misconfigured in your setup. You’re using GLM-5.1 through z.ai, and while Cursor can work with some OpenAI-compatible endpoints, full Agent behavior is most reliable with the providers we officially support end-to-end today. In cases like this, the tool calls can execute, but the tool results are not always round-tripped back to the model in the format the provider expects. So the short version is: this is a limitation in the current BYOK compatibility path for this provider/model combination. For the most dependable Agent behavior today, the safest path is a native Cursor model or an officially supported BYOK provider. Best, Kevin

I’m having the same exact problem with GLM 5.1 in cursor as well

In that case, I’m switching to other IDEs now

Better to just use Kilo Code for GLM 5.1 - They actually have a cursor integration

**glm-5.1** — receives THE EXACT SAME tool response with the same content, but instead of processing the content, it responds with “Unfortunately, Shell tool returned empty output again”. So **the problem is not in the sandbox, not in the Shell tool, not in the environment** — the tool returns the same result to both models. The difference is in how the model interprets it: - **glm-4.7** sees the text in the `tool` message and uses it - **glm-5.1** somehow ignores/doesn’t see the tool response content and generates a response as if the output is empty This is a **glm-5.1** bug in handling tool call results. The model either: 1. Doesn’t parse content from the tool message correctly 2. Confuses the empty `` block (in the instructions) with the actual tool call result 3. Has an issue with how 5.1 processes `last_content_preview` in streaming mode Essentially — this needs to be reported as a bug in glm-5.1. The model receives the data but “thinks” the output is empty.

Having same problem. GLM-5 doesn’t work and GLM-5.1 doesn’t work too…

Same or similar problem here: [image] # Bug: GLM-5 (Modal Research) — Agent tool calls return empty (no output, no error) Bug Reports Same here: Ubuntu 24.04.4, Cursor 3.0.16, https://api.us-west-2.modal.direct/v1/chat/completions also: https://api.z.ai/api/coding/paas/v4 Models: GLM-5-FP8 (modal.direct) , GLM-5 + GLM-5.1 (z.ai) Model GLM-5-TURBO seems to work correct at the moment.

Custom Model cannot see the outputs

Support Bug Reports

JonasH (Jonas) April 10, 2026, 10:29pm 12

Same or similar problem here:

Topic		Replies	Views
# Bug: GLM-5 (Modal Research) — Agent tool calls return empty (no output, no error) Bug Reports byok	5	1056	April 20, 2026
Cursor Native Agent fails with glm-5.2 via OpenAI-compatible provider, while other agents work Bug Reports byok	7	1072	October 4, 2026
GLM 5.2: Tool calls terminate chats Bug Reports chat	43	1615	July 10, 2026
Fresh bugs with custom model Bug Reports byok	20	2094	February 26, 2026
Built-in GLM 5.2 intermittently prints raw tool-call markup instead of invoking Agent tools Bug Reports terminal	0	310	July 8, 2026

Custom Model cannot see the outputs

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