ACP: first session/new per process omits the built-in opencode provider from configOptions #52729

Description

In a fresh opencode acp process, the first session/new returns a configOptions.model list that omits the built-in opencode provider. A second session/new in the same process returns the complete list. The same models are present in opencode models from the start.

Plugins

No response

OpenCode version

2.0.22

Steps to reproduce

initialize            { protocolVersion: 1, clientCapabilities: { fs: {...} }, clientInfo: {...} }
session/new  #1       { cwd: "<abs>", mcpServers: [] }
   -> configOptions[model].options: 771 entries, 0 start with "opencode/"
session/new  #2       { cwd: "<abs>", mcpServers: [] }   (same process, nothing else called)
   -> configOptions[model].options: 744 entries, 9 start with "opencode/"

Observed deterministically across repeated fresh processes:

new #1 -> n=771 opencode=0 current=openrouter/unbiased/pareto-26.10-preview
new #2 -> n=744 opencode=9 current=openrouter/unbiased/pareto-26.10-preview

What is not the cause (tested)

• Not a wait/startup-race that another second fixes: sleeping 0/1/2/3/5/8s after initialize and before the first session/new always yields opencode=0.
• Not model selection per se: re-setting model to the current value (openrouter/unbiased/pareto-…) returns opencode=0; setting configId: "mode" returns opencode=0.
• Forcing the provider works: session/set_config_option(configId="model", value="opencode/…") returns the complete list (9 opencode/*) because resolving a model from that provider loads it.
• session/resume as the first call is also incomplete: resuming a session whose saved model is opencode/big-pickle returns currentValue=opencode/big-pickle but only 771 options, 0 opencode/.

Expected

The first session/new (and session/resume) in a process should return the same complete configOptions as later calls and as opencode models.

Actual

The first session snapshot is built before the built-in opencode provider is registered; creating a session then triggers its load, so subsequent sessions include it.

Likely cause

In packages/opencode/src/acp/service.ts, newSession() builds configOptions from loadDirectorySnapshot() → sdk.config.providers({ directory }). On the first request the built-in opencode provider is not yet present in that map (its registration appears to happen as a side effect of session creation/provider resolution). defaultModelFromConfig() therefore can't prefer it either, and falls back to the globally sorted best model. Later sessions see the now-registered provider.

Screenshot and/or share link

No response

Operating System

Windows

Terminal

No response