[bug]: Anthropic quota unavailable — `claude auth status` does not expose usage data

[vsixer]

Pre-flight checks

• I searched existing issues and did not find a duplicate.
• I verified this on the current production released OpenCode version, or I explain why not below.

OpenCode version tested

1.4.11

opencode-quota version tested

3.0.0

Bug summary

The Anthropic quota rows never appear in /quota, toasts, or the sidebar. The plugin probes claude auth status --json for 5-hour and 7-day usage windows, but the Claude CLI does not include any quota or utilization fields in that response. As a result, parseUsageResponse() always returns null and the provider is silently skipped.
Root cause: Anthropic quota data is not exposed through claude auth status. It is available through a separate undocumented

OAuth usage endpoint:

GET https://api.anthropic.com/api/oauth/usage
Authorization: Bearer <claudeAiOauth.accessToken>
anthropic-beta: oauth-2025-04-20
Response shape:
{
    "five_hour": { "utilization": 0.42, "resets_at": "2026-04-19T17:00:00Z" },
    "seven_day":  { "utilization": 0.61, "resets_at": "2026-04-24T08:00:00Z" }
}

The OAuth token is stored at ~/.claude/.credentials.json under claudeAiOauth.accessToken. This is the same approach used by claude-usage-monitor (https://github.com/aiedwardyi/claude-usage-monitor) and documented independently at https://ianlpaterson.com/blog/tracking-claude-codex-gemini-quotas-from-one-script/.
Suggested fix: in lib/anthropic.ts, when claude auth status confirms authentication but parseUsageResponse() returns null, fall back to calling the OAuth usage endpoint directly and parse the response with the existing parseUsageResponse() logic — it already handles the five_hour/seven_day/utilization/resets_at field names.

Steps to reproduce

1. Install Claude Code CLI and authenticate: claude auth login
2. Confirm auth: claude auth status --json — returns loggedIn: true, subscriptionType: "max", but no quota fields
3. Configure opencode-quota with the anthropic provider enabled (auto-detect)
4. Start OpenCode and run /quota
5. Observe: no Anthropic rows appear in the output

Expected behavior

Anthropic quota rows (5-hour and 7-day usage windows with percentage remaining and reset time) should appear in /quota output, toasts, and the sidebar panel — the same way OpenAI and Z.ai quota rows appear.

Actual behavior

No Anthropic quota rows are shown anywhere. The claude auth status --json response contains no utilization data, so the plugin has nothing to display.

Relevant logs/output

claude --version output:
  2.1.114 (Claude Code)
claude auth status --json output:
  {
    "loggedIn": true,
    "authMethod": "claude.ai",
    "apiProvider": "firstParty",
    "subscriptionType": "max"
  }
  No "quota", "usage", "rate_limits", or "oauth_usage" keys present.

If not tested on current production OpenCode, explain why

No response

[slkiser]

@vsixer Thanks for report, also that is a nicely written blog.

[vsixer]

@slkiser Thanks! It was written with AI assistance, but the investigation and testing were real. Looking forward to the fix.

[slkiser]

Fixed in v3.1.0