{"_id": {"$oid": "6ac4c7b5164e0f17c0b231fb"}, "test_id": "T0984", "benchmark": "business_letters", "date": "2026-04-21", "tags": {"document-type": ["letter"], "writing": ["typed", "handwritten"], "century": [20], "language": ["de"], "layout": ["prose"], "entry-type": ["person", "location"], "task": ["information-extraction"]}, "contributors": ["eric_decker", "maximilian_hindermann", "lea_kasper", "anthea_alberto", "pema_frick", "jose_luis_losada_palenzuela", "sorin_marti", "elena_spadini"], "hidden": false, "config": {"provider": "openrouter", "model": "qwen/qwen3.5-9b", "dataclass": "Document", "temperature": 0.0, "role_description": "You are a historian with keyword knowledge and an expert in the field of 20th century Swiss history", "prompt_file": "prompt.txt", "legacy_test": false}, "prompt": "            IDENTITY and PURPOSE:\n\n            You are presented with a series of images constituting a historical letter. Your task is to extract the\n            values of the following keys from the letter and return them in a JSON file where the values\n            corresponding to each key should be stored as a list, even if there is only a single value for a\n            key:\n\n            - letter_title: Title of the letter.\n            - sender_persons: Name(s) of the person(s) who wrote the letter.\n            - send_date: The exact or approximate date the letter was written.\n            - receiver_persons: Name(s) of the person(s) who received the letter.\n\n            Take a deep breath and think step by step about how to best accomplish this goal. Map out all the claims\n            and implications on a virtual whiteboard in your mind. Do not use OCR. Use the ISO format YYYY-MM-DD for\n            dates. If a piece of information is not included in the letter, set the value for the corresponding key\n            to \"null\". Do not return anything except the JSON file.\n\n            EXAMPLE:\n\n            {\n                \"letter_title\": [\"Petition for Environmental Protection\"],\n                \"send_date\": [\"1993-03-12\"],\n                \"sender_persons\": [\"Lisa Simpson\"],\n                \"receiver_persons\": [\"Mayor Joe Quimby\", \"Seymour Skinner\"],\n            }\n\n            OUTPUT:", "results": {"text": "{\n    \"metadata\": {\n        \"send_date\": [\n            \"1926-02-16\"\n        ],\n        \"letter_title\": [\n            null\n        ],\n        \"sender_persons\": [\n            \"Basler Rheinschifffahrt-Aktiengesellschaft\",\n            \"Gundolf\",\n            \"H. Riller\"\n        ],\n        \"receiver_persons\": [\n            \"Herr Christ\"\n        ]\n    }\n}", "model": "qwen/qwen3.5-9b-20260310", "provider": "openrouter", "finish_reason": "stop", "usage": {"input_tokens": 9229, "output_tokens": 3178, "total_tokens": 12407, "estimated_cost_usd": 0.0013996, "input_cost_usd": 0.0009228999999999999, "output_cost_usd": 0.00047669999999999993}, "duration": 1114.8301022052765, "timestamp": "2026-04-21T14:15:58.711468", "parsed": {"metadata": {"send_date": ["1926-02-16"], "letter_title": [null], "sender_persons": ["Basler Rheinschifffahrt-Aktiengesellschaft", "Gundolf", "H. Riller"], "receiver_persons": ["Herr Christ"], "document_number": "letter01"}}, "conversation_id": "9006ba4b-95f2-43cb-98a1-439f4231f274", "score": {"send_date_tp": 1, "send_date_fp": 0, "send_date_fn": 0, "sender_persons_tp": 0, "sender_persons_fp": 3, "sender_persons_fn": 2, "receiver_persons_tp": 1, "receiver_persons_fp": 0, "receiver_persons_fn": 0}, "raw_response": "{\"id\":\"gen-1776773707-QeNDHE6iweJh2qRDv2mQ\",\"choices\":[{\"finish_reason\":\"stop\",\"index\":0,\"logprobs\":null,\"message\":{\"content\":\"{\\n    \\\"metadata\\\": {\\n        \\\"send_date\\\": [\\n            \\\"1926-02-16\\\"\\n        ],\\n        \\\"letter_title\\\": [\\n            null\\n        ],\\n        \\\"sender_persons\\\": [\\n            \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\",\\n            \\\"Gundolf\\\",\\n            \\\"H. Riller\\\"\\n        ],\\n        \\\"receiver_persons\\\": [\\n            \\\"Herr Christ\\\"\\n        ]\\n    }\\n}\",\"refusal\":null,\"role\":\"assistant\",\"annotations\":null,\"audio\":null,\"function_call\":null,\"tool_calls\":null,\"reasoning\":\"The user wants me to extract metadata from a historical letter.\\nThe letter is in German.\\nI need to identify:\\n1.  **letter_title**: The title of the letter. Looking at the document, there isn't a specific \\\"Title\\\" line like \\\"Re: Boat Proposal\\\". It's a business letter. The header says \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". This is the sender. The content discusses a new boat (\\\"Vogel - Gryff\\\"). I will look for a subject line. There isn't a clear subject line like \\\"Betreff:\\\". However, the header \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" acts as the letterhead. Often, business letters don't have a specific \\\"title\\\" other than the subject matter. I will check if there's a specific subject line. No \\\"Betreff\\\". I will leave it as null or perhaps infer from the content if appropriate, but the prompt asks for \\\"Title of the letter\\\". Usually, this implies a subject line. If absent, null is safer. Wait, looking closely at the first page, top left is the company name. Top right is the date. There is no subject line. I will set letter_title to null.\\n2.  **sender_persons**: The letter is from \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". At the bottom, there is a signature. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\" or similar. The typed name below is \\\"BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signature block says \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signature itself is handwritten. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". Let's look closer. The signature on the right looks like \\\"H. Riller\\\". The signature on the left looks like \\\"Gundolf\\\". Wait, looking at the third image, the signature block is \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signatures are above it. One looks like \\\"Gundolf\\\" and the other \\\"H. Riller\\\". Actually, looking at the very bottom right of page 3, there are two signatures. One looks like \\\"Gundolf\\\" and the other \\\"H. Riller\\\". Wait, let me re-examine. The text says \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signatures are above. One looks like \\\"Gundolf\\\" and the other \\\"H. Riller\\\". Let's look at the context. It's a company letter. The sender is the company. The specific people signing are likely the management. I will list the company name as the primary sender, and perhaps the signatories if legible. The prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". The letterhead is the company. The signatures are individuals. I will include the company name as the sender, as it's a corporate letter. I will also try to read the signatures. The signature on the right looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\". Let's assume the sender is the company \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\n3.  **send_date**: Top right of page 1: \\\"Basel, den 16. Februar 1926.\\\" This translates to Basel, February 16, 1926. I need to convert this to ISO format: 1926-02-16.\\n4.  **receiver_persons**: The addressee is listed on page 1: \\\"Herrn Christ, i/Fa. Paravicini, Christ & Co., Basel. Kaufhausgasse 7.\\\" This means \\\"To Mr. Christ, via Mr. Paravicini, Christ & Co., Basel, Kaufhausgasse 7.\\\" So the primary receiver is \\\"Herr Christ\\\" (Mr. Christ). The company is \\\"Christ & Co.\\\". I will list \\\"Herr Christ\\\" or \\\"Christ & Co.\\\". The salutation is \\\"Sehr geehrter Herr Christ,\\\". So \\\"Herr Christ\\\" is the direct recipient.\\n\\nLet's refine the sender. The letterhead is \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". The signature block confirms this. The specific signatories are likely \\\"Gundolf\\\" and \\\"H. Riller\\\" (or similar). I will stick to the company name as the main sender entity, or list the company. The prompt asks for \\\"person(s)\\\". A company is a legal person. I will list the company name.\\nLet's refine the receiver. \\\"Herrn Christ\\\". I will use \\\"Herr Christ\\\".\\n\\nLet's re-evaluate the \\\"letter_title\\\". There is no explicit title. I will set it to null.\\n\\nLet's re-evaluate the sender. The letter is from \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". The signatures are \\\"Gundolf\\\" and \\\"H. Riller\\\". I will list the company name.\\n\\nLet's re-evaluate the date. \\\"16. Februar 1926\\\" -> \\\"1926-02-16\\\".\\n\\nLet's re-evaluate the receiver. \\\"Herrn Christ\\\".\\n\\nWait, looking at the signature again on page 3. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". Actually, looking really closely at crop 3, the signature on the right looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\". Wait, is it \\\"Gundolf\\\"? It looks like \\\"Gundolf\\\". Let's check if \\\"Gundolf\\\" is a known person associated with this company. A quick mental check or search isn't possible, but I can infer from the visual. The signature looks like \\\"Gundolf\\\". The other looks like \\\"H. Riller\\\".\\nHowever, the prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". The letterhead is the company. The signatures are the people. I will include the company name as the sender, as it's the entity sending the letter. I will also include the signatories if I can be sure. The signature on the right is quite clear: \\\"H. Riller\\\". The one on the left is \\\"Gundolf\\\".\\nActually, looking at the very bottom of page 3, the text \\\"Copie: Herrn Ryniker... Herrn Dr. Krasting...\\\".\\nThe signature block is \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\".\\nThe signatures are above it.\\nI will list \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender.\\n\\nLet's check the receiver again. \\\"Herrn Christ\\\".\\nThe letter is addressed to \\\"Herrn Christ\\\".\\n\\nSo:\\n- letter_title: null (no subject line)\\n- send_date: [\\\"1926-02-16\\\"]\\n- sender_persons: [\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\"] (Maybe add the signatories? \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" is the entity. The prompt asks for \\\"person(s)\\\". A company is a legal person. I'll stick with the company name).\\n- receiver_persons: [\\\"Herr Christ\\\"]\\n\\nWait, looking at the first page, top left: \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\nTop right: \\\"Basel, den 16. Februar 1926.\\\"\\nAddressee: \\\"Herrn Christ, i/Fa. Paravicini, Christ & Co., Basel. Kaufhausgasse 7.\\\"\\nSalutation: \\\"Sehr geehrter Herr Christ,\\\"\\n\\nI will format the date as 1926-02-16.\\nI will format the sender as \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\nI will format the receiver as \\\"Herr Christ\\\".\\n\\nIs there a title? No.\\nIs there a specific subject? No.\\n\\nLet's double check the signature. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". I will add them to the sender list if I feel confident. The prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". The company wrote it, but individuals signed it. I will include the company name as it's the primary sender. I will also include the signatories \\\"Gundolf\\\" and \\\"H. Riller\\\" to be thorough, as they are the ones who physically wrote the signature. Wait, \\\"Gundolf\\\" might be \\\"Gundolf\\\" or \\\"Gundolf\\\". It looks like \\\"Gundolf\\\". The other looks like \\\"H. Riller\\\".\\nActually, looking at the signature on the right, it looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\".\\nLet's look at the \\\"Copie\\\" line. \\\"Herrn Ryniker... Herrn Dr. Krasting\\\".\\nThe signature on the right looks like \\\"H. Riller\\\".\\nThe signature on the left looks like \\\"Gundolf\\\".\\nI will include \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender. I will also include \\\"Gundolf\\\" and \\\"H. Riller\\\" as signatories.\\nActually, the prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". Usually, for a corporate letter, the company name is sufficient. But if I can read the names, I should.\\nLet's look at the signature again. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nWait, looking at the third image, the signature on the right is \\\"H. Riller\\\". The one on the left is \\\"Gundolf\\\".\\nI will list \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender. I will also list \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nActually, I'll just list the company name as it's the most accurate representation of the \\\"sender\\\" in a business context. The prompt asks for \\\"person(s)\\\". A company is a legal person.\\nLet's stick to the company name for sender.\\nReceiver: \\\"Herr Christ\\\".\\n\\nLet's check the date format. \\\"16. Februar 1926\\\" -> \\\"1926-02-16\\\".\\n\\nFinal check on keys:\\n- letter_title: null\\n- sender_persons: [\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\"]\\n- send_date: [\\\"1926-02-16\\\"]\\n- receiver_persons: [\\\"Herr Christ\\\"]\\n\\nWait, looking at the signature again. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". I will add them to the sender list to be safe. \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\", \\\"Gundolf\\\", \\\"H. Riller\\\".\\nActually, looking at the signature on the right, it looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\".\\nLet's look at the \\\"Copie\\\" line. \\\"Herrn Ryniker... Herrn Dr. Krasting\\\".\\nThe signature on the right looks like \\\"H. Riller\\\".\\nThe signature on the left looks like \\\"Gundolf\\\".\\nI will include \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender. I will also include \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nActually, I'll just list the company name. It's the most prominent sender.\\nReceiver: \\\"Herr Christ\\\".\\n\\nLet's refine the receiver. \\\"Herrn Christ\\\".\\nThe letter is addressed to \\\"Herrn Christ\\\".\\nThe company is \\\"Christ & Co.\\\".\\nI will use \\\"Herr Christ\\\".\\n\\nOne more thing. The prompt says \\\"Take a deep breath and think step by step...\\\". I need to output JSON.\\nThe JSON schema requires specific keys.\\n\\\"letter_title\\\", \\\"send_date\\\", \\\"sender_persons\\\", \\\"receiver_persons\\\".\\nAll values must be lists.\\nIf null, use \\\"null\\\".\\n\\nLet's check the date again. \\\"Basel, den 16. Februar 1926.\\\"\\nISO: 1926-02-16.\\n\\nLet's check the sender again. \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\nSignatures: \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nI will include the company name. I will also include the signatories.\\n\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\", \\\"Gundolf\\\", \\\"H. Riller\\\".\\n\\nLet's check the receiver again. \\\"Herrn Christ\\\".\\nI will use \\\"Herr Christ\\\".\\n\\nWait, is there a title? No.\\nSo letter_title is null.\\n\\nFinal plan:\\n- letter_title: null\\n- send_date: [\\\"1926-02-16\\\"]\\n- sender_persons: [\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\", \\\"Gundolf\\\", \\\"H. Riller\\\"]\\n- receiver_persons: [\\\"Herr Christ\\\"]\\n\\nActually, looking at the signature on the right, it looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\".\\nI will include them.\\n\\nWait, looking at the signature on the right, it looks like \\\"H. Riller\\\".\\nThe one on the left looks like \\\"Gundolf\\\".\\nI will include them.\\n\\nLet's check the date again. \\\"16. Februar 1926\\\".\\nISO: 1926-02-16.\\n\\nLet's check the receiver again. \\\"Herrn Christ\\\".\\nI will use \\\"Herr Christ\\\".\\n\\nOne detail: \\\"i/Fa. Paravicini, Christ & Co.\\\". This means \\\"via Mr. Paravicini, Christ & Co.\\\".\\nSo the receiver is \\\"Herr Christ\\\".\\n\\nI will output the JSON.\\n\",\"reasoning_details\":[{\"type\":\"reasoning.text\",\"text\":\"The user wants me to extract metadata from a historical letter.\\nThe letter is in German.\\nI need to identify:\\n1.  **letter_title**: The title of the letter. Looking at the document, there isn't a specific \\\"Title\\\" line like \\\"Re: Boat Proposal\\\". It's a business letter. The header says \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". This is the sender. The content discusses a new boat (\\\"Vogel - Gryff\\\"). I will look for a subject line. There isn't a clear subject line like \\\"Betreff:\\\". However, the header \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" acts as the letterhead. Often, business letters don't have a specific \\\"title\\\" other than the subject matter. I will check if there's a specific subject line. No \\\"Betreff\\\". I will leave it as null or perhaps infer from the content if appropriate, but the prompt asks for \\\"Title of the letter\\\". Usually, this implies a subject line. If absent, null is safer. Wait, looking closely at the first page, top left is the company name. Top right is the date. There is no subject line. I will set letter_title to null.\\n2.  **sender_persons**: The letter is from \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". At the bottom, there is a signature. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\" or similar. The typed name below is \\\"BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signature block says \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signature itself is handwritten. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". Let's look closer. The signature on the right looks like \\\"H. Riller\\\". The signature on the left looks like \\\"Gundolf\\\". Wait, looking at the third image, the signature block is \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signatures are above it. One looks like \\\"Gundolf\\\" and the other \\\"H. Riller\\\". Actually, looking at the very bottom right of page 3, there are two signatures. One looks like \\\"Gundolf\\\" and the other \\\"H. Riller\\\". Wait, let me re-examine. The text says \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\". The signatures are above. One looks like \\\"Gundolf\\\" and the other \\\"H. Riller\\\". Let's look at the context. It's a company letter. The sender is the company. The specific people signing are likely the management. I will list the company name as the primary sender, and perhaps the signatories if legible. The prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". The letterhead is the company. The signatures are individuals. I will include the company name as the sender, as it's a corporate letter. I will also try to read the signatures. The signature on the right looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\". Let's assume the sender is the company \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\n3.  **send_date**: Top right of page 1: \\\"Basel, den 16. Februar 1926.\\\" This translates to Basel, February 16, 1926. I need to convert this to ISO format: 1926-02-16.\\n4.  **receiver_persons**: The addressee is listed on page 1: \\\"Herrn Christ, i/Fa. Paravicini, Christ & Co., Basel. Kaufhausgasse 7.\\\" This means \\\"To Mr. Christ, via Mr. Paravicini, Christ & Co., Basel, Kaufhausgasse 7.\\\" So the primary receiver is \\\"Herr Christ\\\" (Mr. Christ). The company is \\\"Christ & Co.\\\". I will list \\\"Herr Christ\\\" or \\\"Christ & Co.\\\". The salutation is \\\"Sehr geehrter Herr Christ,\\\". So \\\"Herr Christ\\\" is the direct recipient.\\n\\nLet's refine the sender. The letterhead is \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". The signature block confirms this. The specific signatories are likely \\\"Gundolf\\\" and \\\"H. Riller\\\" (or similar). I will stick to the company name as the main sender entity, or list the company. The prompt asks for \\\"person(s)\\\". A company is a legal person. I will list the company name.\\nLet's refine the receiver. \\\"Herrn Christ\\\". I will use \\\"Herr Christ\\\".\\n\\nLet's re-evaluate the \\\"letter_title\\\". There is no explicit title. I will set it to null.\\n\\nLet's re-evaluate the sender. The letter is from \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\". The signatures are \\\"Gundolf\\\" and \\\"H. Riller\\\". I will list the company name.\\n\\nLet's re-evaluate the date. \\\"16. Februar 1926\\\" -> \\\"1926-02-16\\\".\\n\\nLet's re-evaluate the receiver. \\\"Herrn Christ\\\".\\n\\nWait, looking at the signature again on page 3. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". Actually, looking really closely at crop 3, the signature on the right looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\". Wait, is it \\\"Gundolf\\\"? It looks like \\\"Gundolf\\\". Let's check if \\\"Gundolf\\\" is a known person associated with this company. A quick mental check or search isn't possible, but I can infer from the visual. The signature looks like \\\"Gundolf\\\". The other looks like \\\"H. Riller\\\".\\nHowever, the prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". The letterhead is the company. The signatures are the people. I will include the company name as the sender, as it's the entity sending the letter. I will also include the signatories if I can be sure. The signature on the right is quite clear: \\\"H. Riller\\\". The one on the left is \\\"Gundolf\\\".\\nActually, looking at the very bottom of page 3, the text \\\"Copie: Herrn Ryniker... Herrn Dr. Krasting...\\\".\\nThe signature block is \\\"hochachtend BASLER RHEINSCHIFFFAHRT-AKTIEGESELLSCHAFT\\\".\\nThe signatures are above it.\\nI will list \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender.\\n\\nLet's check the receiver again. \\\"Herrn Christ\\\".\\nThe letter is addressed to \\\"Herrn Christ\\\".\\n\\nSo:\\n- letter_title: null (no subject line)\\n- send_date: [\\\"1926-02-16\\\"]\\n- sender_persons: [\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\"] (Maybe add the signatories? \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" is the entity. The prompt asks for \\\"person(s)\\\". A company is a legal person. I'll stick with the company name).\\n- receiver_persons: [\\\"Herr Christ\\\"]\\n\\nWait, looking at the first page, top left: \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\nTop right: \\\"Basel, den 16. Februar 1926.\\\"\\nAddressee: \\\"Herrn Christ, i/Fa. Paravicini, Christ & Co., Basel. Kaufhausgasse 7.\\\"\\nSalutation: \\\"Sehr geehrter Herr Christ,\\\"\\n\\nI will format the date as 1926-02-16.\\nI will format the sender as \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\nI will format the receiver as \\\"Herr Christ\\\".\\n\\nIs there a title? No.\\nIs there a specific subject? No.\\n\\nLet's double check the signature. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". I will add them to the sender list if I feel confident. The prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". The company wrote it, but individuals signed it. I will include the company name as it's the primary sender. I will also include the signatories \\\"Gundolf\\\" and \\\"H. Riller\\\" to be thorough, as they are the ones who physically wrote the signature. Wait, \\\"Gundolf\\\" might be \\\"Gundolf\\\" or \\\"Gundolf\\\". It looks like \\\"Gundolf\\\". The other looks like \\\"H. Riller\\\".\\nActually, looking at the signature on the right, it looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\".\\nLet's look at the \\\"Copie\\\" line. \\\"Herrn Ryniker... Herrn Dr. Krasting\\\".\\nThe signature on the right looks like \\\"H. Riller\\\".\\nThe signature on the left looks like \\\"Gundolf\\\".\\nI will include \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender. I will also include \\\"Gundolf\\\" and \\\"H. Riller\\\" as signatories.\\nActually, the prompt asks for \\\"Name(s) of the person(s) who wrote the letter\\\". Usually, for a corporate letter, the company name is sufficient. But if I can read the names, I should.\\nLet's look at the signature again. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nWait, looking at the third image, the signature on the right is \\\"H. Riller\\\". The one on the left is \\\"Gundolf\\\".\\nI will list \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender. I will also list \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nActually, I'll just list the company name as it's the most accurate representation of the \\\"sender\\\" in a business context. The prompt asks for \\\"person(s)\\\". A company is a legal person.\\nLet's stick to the company name for sender.\\nReceiver: \\\"Herr Christ\\\".\\n\\nLet's check the date format. \\\"16. Februar 1926\\\" -> \\\"1926-02-16\\\".\\n\\nFinal check on keys:\\n- letter_title: null\\n- sender_persons: [\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\"]\\n- send_date: [\\\"1926-02-16\\\"]\\n- receiver_persons: [\\\"Herr Christ\\\"]\\n\\nWait, looking at the signature again. It looks like \\\"Gundolf\\\" and \\\"H. Riller\\\". I will add them to the sender list to be safe. \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\", \\\"Gundolf\\\", \\\"H. Riller\\\".\\nActually, looking at the signature on the right, it looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\".\\nLet's look at the \\\"Copie\\\" line. \\\"Herrn Ryniker... Herrn Dr. Krasting\\\".\\nThe signature on the right looks like \\\"H. Riller\\\".\\nThe signature on the left looks like \\\"Gundolf\\\".\\nI will include \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\" as the sender. I will also include \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nActually, I'll just list the company name. It's the most prominent sender.\\nReceiver: \\\"Herr Christ\\\".\\n\\nLet's refine the receiver. \\\"Herrn Christ\\\".\\nThe letter is addressed to \\\"Herrn Christ\\\".\\nThe company is \\\"Christ & Co.\\\".\\nI will use \\\"Herr Christ\\\".\\n\\nOne more thing. The prompt says \\\"Take a deep breath and think step by step...\\\". I need to output JSON.\\nThe JSON schema requires specific keys.\\n\\\"letter_title\\\", \\\"send_date\\\", \\\"sender_persons\\\", \\\"receiver_persons\\\".\\nAll values must be lists.\\nIf null, use \\\"null\\\".\\n\\nLet's check the date again. \\\"Basel, den 16. Februar 1926.\\\"\\nISO: 1926-02-16.\\n\\nLet's check the sender again. \\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\".\\nSignatures: \\\"Gundolf\\\" and \\\"H. Riller\\\".\\nI will include the company name. I will also include the signatories.\\n\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\", \\\"Gundolf\\\", \\\"H. Riller\\\".\\n\\nLet's check the receiver again. \\\"Herrn Christ\\\".\\nI will use \\\"Herr Christ\\\".\\n\\nWait, is there a title? No.\\nSo letter_title is null.\\n\\nFinal plan:\\n- letter_title: null\\n- send_date: [\\\"1926-02-16\\\"]\\n- sender_persons: [\\\"Basler Rheinschifffahrt-Aktiengesellschaft\\\", \\\"Gundolf\\\", \\\"H. Riller\\\"]\\n- receiver_persons: [\\\"Herr Christ\\\"]\\n\\nActually, looking at the signature on the right, it looks like \\\"H. Riller\\\". The one on the left looks like \\\"Gundolf\\\".\\nI will include them.\\n\\nWait, looking at the signature on the right, it looks like \\\"H. Riller\\\".\\nThe one on the left looks like \\\"Gundolf\\\".\\nI will include them.\\n\\nLet's check the date again. \\\"16. Februar 1926\\\".\\nISO: 1926-02-16.\\n\\nLet's check the receiver again. \\\"Herrn Christ\\\".\\nI will use \\\"Herr Christ\\\".\\n\\nOne detail: \\\"i/Fa. Paravicini, Christ & Co.\\\". This means \\\"via Mr. Paravicini, Christ & Co.\\\".\\nSo the receiver is \\\"Herr Christ\\\".\\n\\nI will output the JSON.\\n\",\"format\":\"unknown\",\"index\":0}]},\"native_finish_reason\":\"stop\"}],\"created\":1776773707,\"model\":\"qwen/qwen3.5-9b-20260310\",\"object\":\"chat.completion\",\"service_tier\":null,\"system_fingerprint\":null,\"usage\":{\"completion_tokens\":3178,\"prompt_tokens\":9229,\"total_tokens\":12407,\"completion_tokens_details\":{\"accepted_prediction_tokens\":null,\"audio_tokens\":0,\"reasoning_tokens\":2724,\"rejected_prediction_tokens\":null,\"image_tokens\":0},\"prompt_tokens_details\":{\"audio_tokens\":0,\"cached_tokens\":0,\"cache_write_tokens\":0,\"video_tokens\":0},\"cost\":0.0013996,\"is_byok\":false,\"cost_details\":{\"upstream_inference_cost\":0.0013996,\"upstream_inference_prompt_cost\":0.0009229,\"upstream_inference_completions_cost\":0.0004767}},\"provider\":\"Together\"}"}, "scoring": {"f1_macro": 0.55, "f1_micro": 0.55, "cost_summary": {"total_input_tokens": 297936, "total_output_tokens": 168578, "total_tokens": 466514, "input_cost_usd": 0.029793600000000003, "output_cost_usd": 0.025286700000000006, "total_cost_usd": 0.055080299999999985}}, "pricing": {"bucket_date": "2026-04-21", "age_days": 0, "input_price_per_million": 0.1, "output_price_per_million": 0.15}, "timing": {"total_response_s": 7828.55, "mean_response_s": 142.34, "slowest_response_s": 1114.83, "inputs_timed": 55, "inputs_stored": 55, "span_s": 35488.18}, "normalized_score": 55.00000000000001}