ACP sessions ignore model selection from Intent (and other ACP clients)

Description

When using Opencode via ACP (Agent Client Protocol) with Intent (or potentially other ACP clients), the model selected in the client is not properly applied to the session. Instead, Opencode defaults to big-pickle.

Expected behavior:

The message should be processed using the model selected in Intent (e.g., kimi-k2.5-free)
Actual behavior:
The message is processed using big-pickle (the default model)
However, the agent context in the system prompt correctly shows the selected model

Evidence:

Agent context correctly shows: "Selected Model": "opencode:opencode/kimi-k2.5-free"
But message record shows: "model":{"providerID":"opencode","modelID":"big-pickle"}

Potential root cause:
Looking at packages/opencode/src/acp/session.ts, the create() method doesn't properly handle the model parameter when passed by ACP clients. The fix in PR #9829 addressed loading existing sessions, but not creating new sessions with a specific model.

Related issues:

ACP loadSessionMode doesn't set model and mode #9828 (ACP loadSessionMode doesn't set model and mode)
Configure default model is not used in ACP #4001 (Configure default model is not used in ACP)
ACP and headless mode does not respect default agent definition #8680 (ACP and headless mode does not respect default agent definition)

Plugins

No response

OpenCode version

1.2.2

Steps to reproduce

Open Intent and select Kimi 2.5 (or any non-default model) as the model
Send a message to Opencode via ACP
Check the session in Opencode database - the message will show the wrong model

Screenshot and/or share link

No response

Operating System

No response

Terminal

No response

Additional evidence captured (Feb 14, 2026):

Message sent: "Test for opencode git issue"
Agent context shows: "Selected Model": "opencode:opencode/kimi-k2.5-free" ✅
Message metadata shows: "model":{"providerID":"opencode","modelID":"big-pickle"} ❌

This confirms the bug is consistent - the agent context correctly displays the selected model, but Opencode internally processes messages with the wrong model.

I am also facing this problem when attempting to integrate with codecompanion

I have a custom config on opencode.json

{
  "$schema": "https://opencode.ai/config.json",
  "theme": "tokyonight",
  "provider": {
    "amazon-bedrock": {
      "options": {
        "region": "eu-central-1"
      },
      "models": {
        "my-fancy-model": {
          "id": "arn:aws:bedrock:eu-central-confidential-information-here"
        }
      }
    }
  }
}

I always get this in the debug output: currentModelId = "opencode/big-pickle"

and when asking the agent itself:

Linking this for potential further investigations

@marcdeop

Did you find a workaround @marcdeop ? This is breaking my workflow

Fixed by AugmentCode team

I'm still seeing this issue in OpenCode 1.17.11 with Xcode 27 beta 2 as the ACP client. It always defaults to big-pickle in create: model.id=big-pickle model.providerID=opencode.
Is there any workaround?

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ACP sessions ignore model selection from Intent (and other ACP clients) #13644

Description

Plugins

OpenCode version

Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

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ACP sessions ignore model selection from Intent (and other ACP clients) #13644

Description

Description

Plugins

OpenCode version

Steps to reproduce

Screenshot and/or share link

Operating System

Terminal

Activity

AlexisGrrd commented on Feb 14, 2026

marcdeop commented on Feb 16, 2026

AlexisGrrd commented on Feb 16, 2026

AlexisGrrd commented on Feb 18, 2026

AlexisGrrd commented on Feb 23, 2026

velouria commented on Jun 30, 2026

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