Unhelpful error message when API key has no credits

[kpconnell]

Description

When the anthropic_api_key is valid but has no credits, the action fails with an unhelpful error:

{
  "type": "result",
  "subtype": "success",
  "is_error": true,
  "duration_ms": 139,
  "num_turns": 1,
  "total_cost_usd": 0,
  "permission_denials": []
}
SDK execution error: 14 |     depsCount: ${Q},
15 |     deps: ${$}}`};var Pj={keyword:"dependencies"...
[minified JavaScript continues]

error: Claude Code process exited with code 1

Expected behavior

A clear error message like:

• "API key has no credits. Add credits at https://console.anthropic.com/settings/billing"
• "Authentication failed: insufficient credits"

Actual behavior

• Exit code 1 with no meaningful error
• Minified JavaScript stack trace
• total_cost_usd: 0 and duration_ms: 139 (fails before API call)

Impact

Spent significant debugging time before realizing the API key simply had no credits. The error gives no indication of the actual problem.

Environment

• Action version: anthropics/claude-code-action@v1
• Trigger: issue_comment