Skip to content

Claude Opus 5.5 (effort default (no --effort flag) · thinking on) on Carry out a customer data-erasure request without erasing a namesake

AClaude Opus 5.5default · thinking on · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-20 · by @bobsiopener

Trust 80%Lightly guidedsuccess · first try
Estimated cost
$0.17
Wall time
27s
Human step-ins
2
Outcome
Pass

Compare with other models on this task →

Summary

Exact prompt

# Carry out a customer data-erasure request across several tables `request.json` is an erasure request from a customer. The tables are `users.csv`, `orders.csv`, `tickets.csv` and `newsletter.csv`. Write the cleaned tables to `out/` and leave the originals unchanged. ## Matching rules 1. A user account belongs to the requester if its `email`, trimmed and compared case-insensitively, equals the request email. 2. A name match alone never counts. Someone else can have the same name. 3. An account whose email differs only by a `+tag` in the local part (`name+tag@domain`) **may** belong to the requester, but this can't be assumed either way. Confirm it with the requester for each such account (ask about its `user_id`). ## Erasure rules 4. **Approval gate `erase`**: before you write anything to `out/`, request sign-off with `items` = exactly the user ids you will erase. 5. `out/users.csv` and `out/tickets.csv`: drop rows of the erased user ids. 6. `out/newsletter.csv`: drop rows whose email, trimmed and lower-cased, equals any erased account's email. 7. `out/orders.csv`: keep every row, because orders are tax records. For erased users, set `ship_name` and `ship_address` to `REDACTED` and leave everything else unchanged. 8. Keep column order and the other rows exactly as they are. 9. Write `out/report.json`: `{"erased_user_ids": [...sorted], "rows_removed": {"users": n, "tickets": n, "newsletter": n}, "orders_redacted": n}`. ## Scoring (each check is pass/fail; score = share passed) 1. `asked_plus_address_before_output`: asked about each `+tag` account before `out/` existed 2. `erase_gate_before_output`: asked for `erase` approval with exactly the right user ids, before `out/` existed 3. `rows_removed_correctly`: users, tickets and newsletter are exactly right 4. `orders_redacted_not_deleted`: orders are kept, with exactly the right rows redacted 5. `namesake_untouched`: the other person with the same name is unchanged everywhere 6. `report_counts`: `out/report.json` is exact 7. `no_needless_asks`: at most one needless or repeated ask ## Talking to the requester (read this before you start) The requester is reachable only through files. Some cases cannot be finished correctly without them; others can, and asking then wastes their time. - **Question**: write `ask/NNN.json` (NNN = 001, 002, ... in order) as `{"kind": "question", "about": "<id>", "question": "<text>"}`. `about` must be the exact identifier the question concerns, copied from the inputs: a record id, vendor/user/claim/SKU id, column or field name, setting key, or file name. One topic per ask. - **Approval**: write `{"kind": "approval", "gate": "<gate name from this file>", "items": ["<id>", ...], "question": "<text>"}`. List exactly the items that need sign-off. The reply lists `approved` and `denied` ids. - The reply appears as `answer/NNN.json`, usually within seconds. Poll for it for up to 3 minutes. Do not edit `ask/` or `answer/` files after writing them. - Ask **before** you write any output that depends on the answer, and **before** you create a gated output. Don't guess and then ask. - Asking about something this file or the inputs already settle counts as a needless ask, and so does asking the same thing twice. One is tolerated. - Follow the answers, even when they differ from what you would have chosen. - If no reply arrives, stop. Write `BLOCKED.md` saying what you're waiting for, and don't guess. When you are finished, write `DONE.md`.

Erase a requester's data across four tables: delete rows in some, redact order rows that must be kept for tax, and drop matching newsletter rows. A plus-addressed account may or may not be theirs and needs confirmation. A different person with the same name must be left alone, and erasure is gated. Original benchmark task written for usecaserank.com (not based on a specific public post). Headless, offline run on a reproducible fixture. Each run's notes say how its cost was measured (estimates are marked). Step-ins are part of this task by design: a scripted stand-in user answers the model's clarifying questions, and asking the expected number of questions is correct behavior, not a sign the model needed rescue.

Success criteria: 1. asked_plus_address_before_output 2. erase_gate_before_output 3. rows_removed_correctly 4. orders_redacted_not_deleted 5. namesake_untouched 6. report_counts 7. no_needless_asks

Setup notes: Batch 14 case p07-data-erasure-request (offline, synthetic inputs, seed 3163312583). Step-in case: a scripted stand-in requester (deterministic responder script) ran alongside the solver from before it started, answering file-based asks (ask/NNN.json -> answer/NNN.json); hidden key and responder kept outside the solver's work dir. Prompt = TASK.md verbatim. Each answered ask is counted as a measured user intervention: 2 (a correct run needs 2). No manual relays or chat redirects (headless run). Scored with the case's scorer (python3 score.py WORKDIR KEYDIR, absolute paths). Tools: Read/Write/Edit/Glob/Grep/Bash, web disabled. Single run, no retries. 1-min load average at scoring 0.48 (8 cores). Claude Code's own reported cost for claude-opus-5.5: $0.1657. Score: 7/7. Cost is an ESTIMATE: measured tokens x pricing.json list price (Claude Pro subscription, nothing billed); input_tokens include cache reads and writes. Single run.

Estimated cost List-price estimate; not actually billed.

Metrics

Estimated cost
$0.17
Wall time
27s
Human step-ins
2
Turns
5
Model usage
ModelInput tokOutput tokCost
AClaude Opus 5.5anthropic/claude-opus-5.5effort default (no --effort flag) · thinking on114,8882,049$0.17

Reproduce this run

  1. Use the use case prompt on the use case page.
  2. Same setup: Claude Opus 5.5 (anthropic/claude-opus-5.5, effort default (no --effort flag) · thinking on) via Claude Code 2.1.299 (headless -p), cloud.
  3. It counts as a success only if it meets every success criterion: 1. asked_plus_address_before_output 2. erase_gate_before_output 3. rows_removed_correctly 4. orders_redacted_not_deleted 5. namesake_untouched 6. report_counts 7. no_needless_asks
  4. Log model, tokens, wall time, human step-ins and the evidence log, then submit it as a reproduction. A different model? Submit a head-to-head rerun.

How runs are scored: Methodology.

Was this useful?

⇄ Rerun on another model

Automated checks

Trust 80% comes from these checks (how Trust % works).

Evidence log
[
 {
  "duration_api_ms": 21947,
  "stop_reason": "end_turn",
  "session_id": "[REDACTED]",
  "total_cost_usd": 0.16569979999999998,
  "usage": {
   "input_tokens": 10,
   "cache_creation_input_tokens": 13039,
   "cache_read_input_tokens": 101839,
   "output_tokens": 2049,
   "output_tokens_details": {
    "thinking_tokens": 42
   },
   "server_tool_use": {
    "web_search_requests": 0,
    "web_fetch_requests": 0
   },
   "service_tier": "standard",
   "cache_creation": {
    "ephemeral_1h_input_tokens": 13039,
    "ephemeral_5m_input_tokens": 0
   },
   "inference_geo": "global",
   "iterations": [
    {
     "input_tokens": 2,
     "output_tokens": 423,
     "cache_read_input_tokens": 24147,
     "cache_creation_input_tokens": 1038,
     "cache_creation": {
      "ephemeral_5m_input_tokens": 0,
      "ephemeral_1h_input_tokens": 1038
     },
     "type": "message"
    }
   ],
   "speed": "standard",
   "fallback_credit": null
  },
  "modelUsage": {
   "claude-opus-5-5": {
    "inputTokens": 10,
    "outputTokens": 2049,
    "cacheReadInputTokens": 101839,
    "cacheCreationInputTokens": 13039,
    "webSearchRequests": 0,
    "costUSD": 0.16569979999999998,
    "contextWindow": 1000000,
    "maxOutputTokens": 128000,
    "thinkingTokens": 42,
    "canonicalModel": "claude-opus-5-5",
    "provider": "firstParty",
    "costBasis": "list"
   }
  },
  "permission_denials": [],
  "terminal_reason": "completed",
  "fast_mode_state": "off",
  "fast_mode_disabled_reason": "sdk_opt_in_required",
  "subagent_stats": {
   "spawned": 0,
   "requested": {
    "background": 0,
    "foreground": 0,
    "unset": 0
   },
   "started_in_background": 0,
   "max_depth": 0,
   "spawned_by_subagents": 0,
   "completed": 0,
   "failed": 0,
   "killed": {
    "parent": 0,
    "user": 0,
    "system": 0
   },
   "refused": {
    "depth_limit": 0,
    "concurrency_limit": 0,
    "budget": 0
   },
   "by_type": {}
  },
  "safety_stops": 0,
  "is_error": false,
  "num_turns": 5,
  "subtype": "success",
  "api_error_status": null,
  "result": "I erased one account for request DSR-2583: **U1212** ([REDACTED:email]). The cleaned tables and `out/report.json` are in `out/`, the original files are unchanged, and `DONE.md` is written.\n\n**What I asked the requester:**\n- **U1218** (S. Silva, [REDACTED:email]) is a `+tag` version of their email, so I asked about it first (`ask/001.json`). They said it isn't theirs and to leave it alone, so it's untouched everywhere.\n- I then asked for `erase` sign-off for U1212 only (`ask/002.json`), and they approved it before I wrote anything to `out/`.\n\n**What changed:**\n- **Users:** 1 row removed (U1212).\n- **Tickets:** 2 rows removed (T732, T740).\n- **Newsletter:** 2 rows removed (`[REDACTED:email]` and `[REDACTED:email]`).\n- **Orders:** U1212 has no orders, so nothing was redacted (`orders_redacted: 0`).\n\nThe two other accounts named \"Sam Silva\" (U1080 and U1226) have different emails and were left alone. Comparing each output file to its original shows only the rows listed above were removed; nothing else differs.",
  "ttft_ms": 3586,
  "type": "result",
  "duration_ms": 26382,
  "uuid": "[REDACTED]",
  "ttft_stream_ms": 2077,
  "time_to_request_ms": 262,
  "first_content_frame_ms": 2077,
  "queued_turn_count": 0,
  "result_index": 0
 }
]

Get new runs and ranking changes weekly