VSCode extension hardcodes invalid model ID 'claude-haiku-4-5-20251001' for internal background task

Description

The Claude Code VSCode extension's bundled extension.js hardcodes a non-existent model ID for an internal background helper task, causing a 400 error:

API Error: 400 anthropic_messages: Invalid model name passed in model=claude-haiku-4-5-20251001. Call /v1/models to view available models for your key.

Root cause

Somewhere in the extension's internal query invocation (used for a background/helper task with thinking: {type: "disabled"}), the model is hardcoded as:

model:"claude-haiku-4-5-20251001"

claude-haiku-4-5-20251001 has never been a valid model ID — it appears to be claude-haiku-4-5 with a stray date suffix appended. The correct current model ID is claude-haiku-4-5 (no date suffix).

Affected versions

Confirmed present in the bundled extension.js of every version I had installed:

• 2.1.273
• 2.1.274
• 2.1.276
• 2.1.278

Example match (2.1.278):

h$({prompt:V,options:{cwd:Q,permissionMode:"default",model:"claude-haiku-4-5-20251001",systemPrompt:vo0,thinking:{type:"disabled"},pathToClaudeCodeExecutable:Y,executableArgs:J,env:z,...

Steps to reproduce

1. Install Claude Code VSCode extension (any of the affected versions).
2. Trigger whatever internal flow invokes this background helper query (it fires without direct user action — surfaced as a 400 API error during normal use).
3. Observe the 400 error citing model=claude-haiku-4-5-20251001.

Expected behavior

The internal helper task should use a valid model ID (claude-haiku-4-5) and succeed without error.

Workaround

Patched the bundled extension.js locally, replacing claude-haiku-4-5-20251001 with claude-haiku-4-5 in each installed version. This is not durable — it gets overwritten on the next extension auto-update.

Environment

• OS: macOS (Darwin 25.6.0)
• Extension versions: 2.1.273, 2.1.274, 2.1.276, 2.1.278

🤖 Generated with Claude Code