[Bug] Claude Opus 4.7 failed to verify externally-documented API requirements for Aligo Kakao Alimtalk templates

Bug Description
[Aligo Alimtalk template — model failed to verify externally documented API behavior] Setup: - Plan: Claude Max x5 - Model: Opus 4.7 (claude-opus-4-7) - Project: balju-v2 (production B2B SaaS, balju-v2.questloom.io) What happened: For ~1 week (2026-04-20 to 2026-04-27), I asked Claude Code why my Aligo Kakao Alimtalk templates (UH_2681, UH_2682) were stuck in 검수대기 (Pending Review) state. Claude Code analyzed the template content, found nothing obviously wrong, and concluded with confidence: "Most likely cause is queue congestion. Just wait." I asked it to handle autonomously ("알아서해봐"). It did not consult Aligo docs, did not call any verification API, and maintained the wait-it-out recommendation across multiple turns. Actual root cause (per Aligo support, 2026-04-27): Templates created via API also require a separate review-request call: POST https://kakaoapi.aligo.in/akv10/template/request/ This is in Aligo's public API documentation. Templates were sitting in "등록" (Created) state, never in the actual review queue. Why this matters: - Not a hallucination on a hard problem - Refusal to verify externally-documented API behavior despite explicit autonomous-execution authorization - Real downstream impact: paying B2B customers (incl. first-paid beta customer) lost a week of automated alimtalk delivery Conversation transcript: this CLI session, Conversation ID 215474072013315 on Anthropic Support. Filed in parallel with a goodwill credit request via support@anthropic.com.

Environment Info

• Platform: darwin
• Terminal: iTerm.app
• Version: 2.1.116
• Feedback ID: f4e7536e-1a7d-4627-860d-7ea6308e74d9

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/woojeonjang/.local/share/claude/versions/2.1.116 (expected in multi-process scenarios)\n    at Yl6 (/$bunfs/root/src/entrypoints/cli.js:2752:2177)\n    at U88 (/$bunfs/root/src/entrypoints/cli.js:2752:1257)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T10:55:49.662Z"},{"error":"Error: EISDIR: illegal operation on a directory, read '/Users/woojeonjang/Documents/dev/balju_v2/app/api/orders'\n    at RKH (/$bunfs/root/src/entrypoints/cli.js:1564:144)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:04.521Z"},{"error":"Error: EISDIR: illegal operation on a directory, read '/Users/woojeonjang/Documents/dev/balju_v2'\n    at RKH (/$bunfs/root/src/entrypoints/cli.js:1564:144)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:06.219Z"},{"error":"Error: File does not exist. Note: your current working directory is /Users/woojeonjang/Documents/dev/balju_v2.\n    at call (/$bunfs/root/src/entrypoints/cli.js:4741:7630)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:09.791Z"},{"error":"Error: File does not exist. Note: your current working directory is /Users/woojeonjang/Documents/dev/balju_v2.\n    at call (/$bunfs/root/src/entrypoints/cli.js:4741:7630)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:09.800Z"},{"error":"Error: File does not exist. Note: your current working directory is /Users/woojeonjang/Documents/dev/balju_v2.\n    at call (/$bunfs/root/src/entrypoints/cli.js:4741:7630)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:10.200Z"},{"error":"Error: File does not exist. Note: your current working directory is /Users/woojeonjang/Documents/dev/balju_v2.\n    at call (/$bunfs/root/src/entrypoints/cli.js:4741:7630)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:14.572Z"},{"error":"Error: File does not exist. Note: your current working directory is /Users/woojeonjang/Documents/dev/balju_v2.\n    at call (/$bunfs/root/src/entrypoints/cli.js:4741:7630)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:14.845Z"},{"error":"Error: File does not exist. Note: your current working directory is /Users/woojeonjang/Documents/dev/balju_v2.\n    at call (/$bunfs/root/src/entrypoints/cli.js:4741:7630)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-21T11:13:26.857Z"},{"error":"AxiosError: Request failed with status code 401\n    at $d (/$bunfs/root/src/entrypoints/cli.js:110:1194)\n    at <anonymous> (/$bunfs/root/src/entrypoints/cli.js:115:12712)\n    at emit (node:events:92:22)\n    at endReadableNT (internal:streams/readable:865:50)\n    at processTicksAndRejections (native:7:39)\n    at request (/$bunfs/root/src/entrypoints/cli.js:117:2467)\n    at async stL (/$bunfs/root/src/entrypoints/cli.js:3090:14589)\n    at async V1q (/$bunfs/root/src/entrypoints/cli.js:3090:151…

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