Summary

When using google-antigravity provider with Gemini 3.1 Pro, OpenClaw sends the model ID as gemini-3.1-pro in the API request body. The Antigravity Cloud Code Assist API rejects this with a 404: "Requested entity was not found" because it requires a thinking-tier suffix (-low or -high) for all Gemini 3 Pro variants.

Root Cause

The Antigravity API has different model ID requirements depending on the model family:

The existing model catalog already correctly uses gemini-3-pro-low and gemini-3-pro-high (with tier suffix), but the forward-compat resolution for Gemini 3.1 Pro creates a model entry with bare id: "gemini-3.1-pro" — missing the required tier suffix.

Evidence

OpenCode (antigravity-auth plugin v1.6.0) works correctly because its model-resolver in src/plugin/transform/model-resolver.ts automatically appends -low as default tier:

// From opencode-antigravity-auth plugin
if (isGemini3Pro && !tier && !isImageModel) {
  antigravityModel = `${modelWithoutQuota}-low`;  // gemini-3.1-pro → gemini-3.1-pro-low
}

OpenClaw sends model: "gemini-3.1-pro" (without suffix) via buildRequest() in google-gemini-cli.js:706:

return {
  project: projectId,
  model: model.id,  // "gemini-3.1-pro" — missing -low suffix
  request,
  ...
};

Steps to Reproduce

1. Configure google-antigravity provider with OAuth
2. Set primary model to google-antigravity/gemini-3.1-pro
3. Send any message
4. Observe 404 error in logs: Cloud Code Assist API error (404): Requested entity was not found.
5. After 404, google-antigravity goes into cooldown, causing cascade failures

Logs

FailoverError: Cloud Code Assist API error (404): Requested entity was not found.

Followed by:

FailoverError: No available auth profile for google-antigravity (all in cooldown or unavailable).

Fix

The forward-compat model resolution and catalog synthesis need to use gemini-3.1-pro-low and gemini-3.1-pro-high as model IDs for google-antigravity, matching the existing pattern for gemini-3-pro-low/gemini-3-pro-high.

PR #21257 already implements this correctly — it adds both gemini-3.1-pro-low and gemini-3.1-pro-high catalog entries for google-antigravity and handles the forward-compat resolution properly.

Affected Components

• src/agents/model-forward-compat.ts — resolution returns bare gemini-3.1-pro instead of gemini-3.1-pro-low
• src/agents/model-catalog.ts — catalog synthesis needs -low/-high entries for google-antigravity
• src/commands/models/list.registry.ts — model listing needs the tier-suffixed IDs

Environment

• OpenClaw: 2026.2.21-2
• Provider: google-antigravity (Google Pro subscription)
• OS: Proxmox (Debian)

Related Issues

• [Bug]: Antigravity Gemini 3 is gone #22559 — Antigravity Gemini 3 is gone
• [Feature]: the Gemini new models from anti-gravity are not in the model section, and I can't use the Gemini 3 models as well, so pls fix the anti-gravity models and update it to the latest. #22603 — Antigravity models not available
• [Bug]: Gemini 3.0 Pro No Longer Supported in Antigravity #21875 — Gemini 3.0 Pro no longer supported
• Add gemini-3.1-pro-preview to google-gemini-cli provider model catalog #21176 — Add gemini-3.1-pro-preview

Related PRs

• # feat: add Gemini 3.1 Pro (low/high reasoning) model support #21257 — Implements the correct fix (adds low/high reasoning model support)
• fix(models): add fallback Gemini 3.1 Pro Preview catalog entry #22337 — Partial fix for google provider only (merged)
• fix(models): add gemini-3.1-pro-preview forward-compat for google-gemini-cli provider #21181 — Forward-compat for google-gemini-cli (different provider)