qwen3-coder fails to call edit tool

Description

When using https://openrouter.ai/qwen/qwen3-coder:free it fails to call the edit tool.

It fails over and over again with:

Error: The edit tool was called with invalid arguments: [
  {
    "expected": "string",
    "code": "invalid_type",
    "path": [
      "oldString"
    ],
    "message": "Invalid input: expected string, received object"
  },
  {
    "expected": "string",
    "code": "invalid_type",
    "path": [
      "newString"
    ],
    "message": "Invalid input: expected string, received object"
  }
].
Please rewrite the input so it satisfies the expected schema.

Plugins

none

OpenCode version

1.1.1

Steps to reproduce

Set provider to Openrouter
Set model to qwen/qwen3-coder:free
Ask it to make any edits

Screenshot and/or share link

Operating System

NixOS

Terminal

xterm

This issue might be a duplicate of existing issues. Please check:

Tool.edit should recieve json object #6838: Tool.edit should receive json object - Similar issue where LLM passes JSON objects instead of strings to edit tool parameters

The root cause appears to be that some LLM models (like Qwen3-coder) pass JSON objects for oldString and newString when they should pass strings. This is similar to the broader issue documented in #6838 where models struggle with properly stringifying JSON content for the edit tool.

Feel free to ignore if your specific case differs from these existing issues.

Facing same on Macos 15.6.1 and Ghostty

Same here. Qwen is hard to use with opencode and always made problems. AFAIK: the problem is not opencode in particular but also qwen3 misunderstanding the tools/capabilities provided by opencode. I heard of proxies acting as "man in the middle" fixing tool calling for qwen3.
Edit: Please notice that those proxies only have been tested with Qwen3-Coder-30B-A3B-Instruct. Other Qwen3 variations may have different problems. I had no luck the versions provided by ollama

Same problems with GLM4.7

I have same issue with GLM 4.7-flash & qwen3-coder .
i'm using ollama (localy)

Every time I want read or write files using ai. I will occur error.
And this issues don't solved in opencode@1.1.15

It's so sad

same on qwen 3 coder next 80b
sometimes its go on with cat

Switch orchestrator to Coder model and consolidate P0/P1 fixes

Same problem with gemini-3-pro-preview high (variant)

Very similar problem with Qwen3-Coder-Next. I receive this consistently when it tries to call the write tool:

The write tool was called with invalid arguments: [ { "expected": "string", "code": "invalid_type", "path": [ "filePath" ], "message": "Invalid input: expected string, received undefined" } ]. Please rewrite the input so it satisfies the expected schema.

I receive this error a fair bit. Eventually it figures out to use a different method, or I cancel and tell it to use a different method.

I get this quite a but with Qwen3-Coder-Next. not sure if it has anything to do with this long token generation steps (more than 1500 fore example).

I am using LM Studio 0.4.2 (Build 2), OpenCode 1.1.62 and Llama 2.2.0 runtime in LM Studio. Model is from Qwen3-Coder-Next Unsloth MXFP4.

There's some upstream bugs:
ggml-org/llama.cpp#19430 hard crash
ggml-org/llama.cpp#19382 broken filePath json

Is there any known workaround?

I was gonna try GLM 4.7 but now I've read it has the same problem.

This problem slows down the agent substantially and wastes context.

After using opencode for some time now, write issues happens mostly when context window reaches above 50-70% of model's configured context window limit. Thinking if its the model's attention span or just hallucinations that cause looping when invoking tools

Is this the same issue? I'm using Qwen3-coder 480B in OpenCode 1.4.0

→ Read build.sh [limit=5, offset=56]
Now I'll make the correct edit with the exact content:
← Edit build.sh 
Could not find oldString in the file. It must match exactly, including whitespace, indentation, and line endings.

Facing a similar issue. Qwen Coder Next hosted through LM Studio:
Processes promt for several minutes, only for tool call to fail

fix(tool): coerce object args to string in edit and write tools

Can someone take a look at the PR's and approve one of them, there seem to be 3 addressing this, with one all green.

I am no longer able to reproduce this issue with Qwen3.5 . Maybe it was fixed in a recent opencode release?

I just got the same error using Qwen 3.6 plus:

OpenCode 1.2.15
Provider: Opencode Go

INFO  2026-04-19T11:41:40 +0ms service=permission permission=todowrite pattern=* action={"permission":"*","pattern":"*","action":"allow"} evaluated
INFO  2026-04-19T11:41:40 +4ms service=bus type=todo.updated publishing
INFO  2026-04-19T11:41:40 +1ms service=bus type=message.part.updated publishing
INFO  2026-04-19T11:41:40 +1ms service=bus type=message.part.updated publishing
INFO  2026-04-19T11:41:40 +78ms service=snapshot hash=65861c6391ae10aa5c82d4542a47086f1c32362a
 cwd=/home/***/Documents/freelo/udc/wtwh/query_newsletter_leads git=/home/***/.local/share/opencode/snapshot/9aec4f28ff886aa347c24f7b3ce292f0a53b23ee tracking
ERROR 2026-04-19T11:41:40 +1ms service=session.processor error=[
  {
    "expected": "string",
    "code": "invalid_type",
    "path": [
      "reason"
    ],
    "message": "Invalid input: expected string, received object"
  }
] stack="ZodError: [\n  {\n    \"expected\": \"string\",\n    \"code\": \"invalid_type\",\n    \"path\": [\n      \"reason\"\n    ],\n    \"message\": \"Invalid input: expected string, received object\"\n  }\n]" process
INFO  2026-04-19T11:41:40 +1ms service=bus type=session.status publishing
INFO  2026-04-19T11:41:44 +4003ms service=llm providerID=opencode-go modelID=qwen3.6-plus sessionID=ses_25a76d86fffeMgxg2jhROK462N small=false agent=build mode=primary stream
INFO  2026-04-19T11:41:44 +3ms service=bus type=session.status publishing
INFO  2026-04-19T11:41:49 +4412ms service=snapshot hash=65861c6391ae10aa5c82d4542a47086f1c32362a

@ariel-udc

@ariel-udc can you retry with the latest opencode version - 1.14.18? Qwen 3.5 & 3.6 were able to write json objects to files here.

@peterdenham

@peterdenham Problem still occurs on latest opencode with qwen3.6-35b-a3b

Native file-io tool calls work seamless on Claude Code. Issue seems to be only in opencode.

@peterdenham Problem still occurs on latest opencode with qwen3.6-35b-a3b

Native file-io tool calls work seamless on Claude Code. Issue seems to be only in opencode.

I just published a tool to bridge this issue and hopefully more:

https://github.com/the-webguys/llama-BridgeAI

To stay organized issues are automatically closed after 60 days of no activity. If the issue is still relevant please open a new one.

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qwen3-coder fails to call edit tool #6918

Description

Plugins

OpenCode version

Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

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qwen3-coder fails to call edit tool #6918

Description

Description

Plugins

OpenCode version

Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

Activity

github-actions commented on Jan 5, 2026

PhantomKnight287 commented on Jan 6, 2026

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peterdenham commented on Apr 19, 2026

ariel-udc commented on Apr 19, 2026

peterdenham commented on Apr 19, 2026

bhuv-z commented on Apr 21, 2026

the-webguys commented on Apr 22, 2026

github-actions commented on Jul 3, 2026

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