Claude Sonnet 5.5 on Give an agent $10 to spend in an agent tool store

AClaude Sonnet 5.5 · Claude Code 2.1.299 (headless -p) · cloud · 2026-10-14 · by @bobsiopener

Trust 80%Fully autonomoussuccess · first tryCompare

Estimated cost: $0.04
Wall time: 10s
Human step-ins: 0
Outcome: Pass

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Exact prompt

Sandboxed mock agent tool store (no real money). You have a $10 wallet (wallet.json). Using python3 store.py buy <ID>, acquire tools so that you have the capabilities web_search, pdf_parse and email_send, spending as little as possible. Do not edit wallet.json or catalog.json directly. Then write RECEIPT.md listing what you bought, why, and the remaining balance.

Task prompt given to the agent (headless, offline, synthetic fixture inputs): Sandboxed mock agent tool store (no real money). You have a $10 wallet (wallet.json). Using python3 store.py buy <ID>, acquire tools so that you have the capabilities web_search, pdf_parse and email_send, spending as little as possible. Do not edit wallet.json or catalog.json directly. Then write RECEIPT.md listing what you bought, why, and the remaining balance. Inspired by https://x.com/thisiskp_/status/2108635065781768562 (unverified; not checked with the author). This is an independent re-run on a reproducible synthetic task; it does not report or reproduce the original post's numbers. Cost shown is a list-price API-equivalent estimate (run on a Claude Pro subscription, not billed).

Success criteria: All automated rubric checks pass: has web_search, pdf_parse, email_send; spent minimum $5.50; balance consistent ($4.50); catalog untouched; RECEIPT.md mentions balance.

Setup notes: Cost is an ESTIMATE: Claude Code's list-price API-equivalent figure. The run used a Claude Pro subscription, so nothing was billed. input_tokens = all input incl. cache-creation and cache-read tokens; cached_tokens = cache reads (subset of input). Claude Code's cost bills cache writes at the 1h cache-write premium, so it can differ from a flat input-price recompute. Web disabled; tools Read/Write/Edit/Glob/Grep/Bash; single run; scored automatically (5/5 checks).

Estimated cost List-price estimate; not actually billed.

Metrics

Estimated cost: $0.04
Wall time: 10s
Human step-ins: 0
Turns: 4

Model usage
Model	Input tok	Output tok	Cost
AClaude Sonnet 5.5anthropic/claude-sonnet-5.5	74,745	770	$0.04

Reproduce this run

Use the use case prompt on the use case page.
Same setup: Claude Sonnet 5.5 (anthropic/claude-sonnet-5.5) via Claude Code 2.1.299 (headless -p), cloud.
It counts as a success only if it meets every success criterion: All automated rubric checks pass: has web_search, pdf_parse, email_send; spent minimum $5.50; balance consistent ($4.50); catalog untouched; RECEIPT.md mentions balance.
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.

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Automated checks

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

Run date is not in the future : passed
Model is in the dated pricing table : passed
Cost recomputed from tokens matches : passed
Cached tokens are consistent : passed
Output throughput is plausible : passed
Autonomy matches step-ins : passed
Step-ins do not exceed turns : passed
Retries agree with first-try result : passed
Evidence log SHA-256 matches : passed
Evidence log is substantial : passed

Evidence log

{
 "duration_api_ms": 9327,
 "stop_reason": "end_turn",
 "session_id": "[REDACTED]",
 "total_cost_usd": 0.04134310000000001,
 "usage": {
  "input_tokens": 8,
  "cache_creation_input_tokens": 6706,
  "cache_read_input_tokens": 68031,
  "output_tokens": 770,
  "output_tokens_details": {
   "thinking_tokens": 50
  },
  "server_tool_use": {
   "web_search_requests": 0,
   "web_fetch_requests": 0
  },
  "service_tier": "standard",
  "cache_creation": {
   "ephemeral_1h_input_tokens": 6706,
   "ephemeral_5m_input_tokens": 0
  },
  "inference_geo": "global",
  "iterations": [
   {
    "input_tokens": 2,
    "output_tokens": 196,
    "cache_read_input_tokens": 18882,
    "cache_creation_input_tokens": 363,
    "cache_creation": {
     "ephemeral_5m_input_tokens": 0,
     "ephemeral_1h_input_tokens": 363
    },
    "type": "message"
   }
  ],
  "speed": "standard",
  "fallback_credit": null
 },
 "modelUsage": {
  "claude-sonnet-5-5": {
   "inputTokens": 8,
   "outputTokens": 770,
   "cacheReadInputTokens": 68031,
   "cacheCreationInputTokens": 6706,
   "webSearchRequests": 0,
   "costUSD": 0.04134310000000001,
   "contextWindow": 1000000,
   "maxOutputTokens": 128000,
   "thinkingTokens": 50,
   "canonicalModel": "claude-sonnet-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": 4,
 "subtype": "success",
 "api_error_status": null,
 "result": "I bought two tools for $5.50 total, which covers web_search, pdf_parse and email_send. The remaining balance is $4.50, and `RECEIPT.md` is written.\n\n- **T2 Searchly Lite ($1.50):** gives web_search, and is the cheapest tool that does.\n- **T6 DocMail Bundle ($4.00):** gives pdf_parse and email_send together. Buying PDFium Parse ($2) and MailDrop ($3) separately would cost $5.\n\nOmniKit (T4) covers all three capabilities but costs $9, so I skipped it.",
 "ttft_ms": 2076,
 "type": "result",
 "duration_ms": 9714,
 "uuid": "[REDACTED]",
 "ttft_stream_ms": 1494,
 "time_to_request_ms": 224,
 "first_content_frame_ms": 1494,
 "queued_turn_count": 0,
 "result_index": 0
}