Claude 3.7's FULL System Prompt
Analysis of the Leaked System Prompt of Anthropic's Claude Model
Last updated
Analysis of the Leaked System Prompt of Anthropic's Claude Model
Last updated
Anthropic's Claude has emerged as a prominent large language model, recognized for its sophisticated reasoning abilities and its capacity to handle multimodal inputs.1 Positioned as a versatile artificial intelligence, Claude is designed to assist users across a spectrum of tasks, from individual brainstorming sessions to complex team-based projects, often demonstrating performance that rivals or even surpasses that of other leading models such as OpenAI's GPT-4.1 At the core of how these advanced language models operate are system prompts, which function as a foundational layer of instructions that dictate the AI's behavior, define its operational parameters, and govern its access to various tools.5 These prompts essentially set the stage for every interaction, shaping the AI's persona and ensuring adherence to specific guidelines established by its developers. Recently, a significant event occurred within the AI community: the system prompt for Anthropic's Claude model, specifically Claude 3.7 Sonnet, was reportedly leaked, making its intricate details publicly available.10 This leak holds considerable significance for researchers, developers, and technology enthusiasts alike, as it offers an unprecedented glimpse into the inner workings and design principles that underpin one of the most advanced language models currently available.
System prompts play a pivotal role in directing the behavior and capabilities of large language models.5 These prompts serve as a crucial mechanism for providing context, specific instructions, and overarching guidelines to the AI before it processes any user input.8 In essence, they pre-define the AI's operational framework for each interaction, acting as a form of in-context learning that steers the model towards desired responses and actions. By leveraging system prompts, developers can effectively manage the AI's responses and ensure they align with intended use cases and ethical considerations. These prompts can be used to define the AI's persona, influencing its communication style and the nature of the insights it provides.7 For instance, through the system parameter in the API, developers can assign specific roles to Claude, such as a seasoned data scientist or a legal counsel, which in turn shapes the tone, vocabulary, and focus of its responses.7 Examples of this include instructing Claude to adopt a formal or informal tone, or to provide analysis from a particular professional perspective.8 Furthermore, system prompts are instrumental in enabling access to and governing the use of external tools and functionalities, such as web search capabilities and code execution environments.6 A substantial portion of Claude's system prompt is reportedly dedicated to defining and instructing the model on how to utilize various tools that are often facilitated through Model Context Protocol (MCP) servers.6 This intricate set of instructions ensures that Claude can effectively leverage these tools to enhance its problem-solving abilities and provide more comprehensive and contextually relevant responses to user queries.
The full system prompt for Claude 3.7 Sonnet was reportedly discovered and made publicly available in May 2025, finding its way onto platforms such as GitHub.10 The leak involved the posting of the prompt in repositories named "asgeirtj/system_prompts_leaks" and "jujumilk3/leaked-system-prompts".10 This event provided an unprecedented level of insight into the operational instructions of a leading large language model. The size of the leaked prompt is reported to be substantial, encompassing approximately 24,000 to 25,000 tokens, which translates to over 100,000 characters.6 This considerable length makes Claude's system prompt significantly larger than those of other prominent models, such as OpenAI's o4-mini, which is reportedly much shorter.6 The leaked files included key documents such as claude-3.7-sonnet-full-system-message-humanreadable.md, which offered a more easily understandable version, and claude-3.7-full-system-message-with-all-tools.md, which contained the complete prompt including detailed instructions for all the tools Claude can access.10 While the exact source of this information remains unconfirmed, speculation within the AI community suggests that the leak likely originated internally from Anthropic.10 As of the time of the leak, Anthropic had not released any official statement acknowledging or addressing the public availability of its system prompt.
The leaked system prompt of Claude 3.7 Sonnet contains several key sections that provide insights into its design and operational guidelines. One notable aspect is the set of basic personality and behavioral guidelines that define Claude's core characteristics. The prompt reportedly instructs Claude to embody traits such as being helpful, intelligent, and kind, while also possessing the capacity to lead conversations and engage in a more proactive, human-like manner.5 It also includes guidelines on how Claude should modulate its responses based on the complexity of the user's query, providing concise answers for simple questions and more thorough explanations for complex ones.9 Furthermore, the prompt specifies certain conversational behaviors, such as the ability to offer its own observations or suggest topics for discussion, moving beyond a purely reactive role.5
A significant portion of the system prompt is dedicated to comprehensive safety and moderation protocols, reflecting Anthropic's strong commitment to responsible AI development. These detailed instructions aim to prevent the generation of harmful content, including strict restrictions on material involving minors to prevent sexualization, grooming, abuse, or any form of harm to children.10 The prompt also explicitly prohibits the generation of information that could be used to create chemical, biological, or nuclear weapons, as well as forbidding the creation of malicious code such as malware, exploits, spoof websites, ransomware, and viruses.10 When utilizing search tools, Claude is instructed to avoid sources that promote hate speech, racism, violence, or discrimination.11 Additionally, the system prompt reportedly includes a specific policy against generating any form of election-related material, likely to prevent potential misuse or undue influence on democratic processes.10
The prompt also contains detailed instructions for utilizing various tools to enhance Claude's capabilities. For the web search tool, the guidelines specify when and how it should be employed, emphasizing its use for accessing recent information, real-time data, news updates, and current API documentation, particularly when Claude's internal knowledge base might be insufficient.6 Furthermore, the prompt includes instructions on how Claude should cite sources from its web searches, along with strict limitations on quoting copyrighted content to ensure adherence to intellectual property rights.10 Claude also has access to a code execution environment, often referred to as the analysis tool, which allows it to write and run JavaScript code for tasks such as data analysis and complex computations.23 The system prompt likely provides guidance on when and how to invoke this tool, as well as its capabilities for handling data, performing various analyses, and even generating visualizations to present findings.23 Another significant functionality governed by the system prompt is artifact generation, which enables Claude to create outputs such as code snippets, charts, and documents.10 The prompt reportedly specifies the appropriate use cases for these artifacts, including original creative writing, in-depth analytical content, and custom code solutions for specific user problems.10
The system prompt also includes strict copyright protection measures, underscoring Anthropic's commitment to respecting intellectual property. It contains explicit instructions prohibiting the reproduction of any copyrighted material in Claude's responses, even if that material is sourced from web search results or intended for inclusion in generated artifacts.10 To further mitigate the risk of copyright infringement, the prompt imposes a specific rule that limits the use of quotes from any single search result to a maximum of one short excerpt.10 Moreover, there is a clear and firm policy in place that prohibits Claude from reproducing or translating song lyrics, reflecting legal agreements and ongoing efforts to prevent copyright violations in this specific domain.18
Finally, the leaked prompt reportedly contains specific directives for handling particular scenarios. One such directive is an instruction to avoid using February 29th as a date when dealing with time-related queries, which is a somewhat unusual but potentially relevant guideline.16 Additionally, the prompt includes detailed instructions on how Claude should approach counting tasks, emphasizing the importance of step-by-step thinking and explicit enumeration of the items being counted before providing the final answer.6 This level of granularity in the instructions highlights the meticulous approach taken to ensure Claude's accuracy and reliability across a wide range of tasks.
The public availability of Claude's system prompt carries several significant implications for the AI community and beyond. One of the most immediate concerns is the increased risks of prompt injection and adversarial attacks.10 With detailed knowledge of the system's underlying instructions, malicious actors may find it easier to craft prompts that can bypass the model's safety mechanisms, manipulate its behavior, or extract sensitive information. Understanding the specific constraints and guidelines embedded in the prompt could enable more sophisticated attempts to circumvent these safeguards, potentially leading to unintended or harmful outputs. The leak also raises important ethical considerations surrounding transparency and security in AI.10 While transparency in AI development is often lauded as a means to foster trust and understanding, the disclosure of highly sensitive internal operational details like system prompts can create a tension with security concerns. The debate continues within the AI community about where to draw the line between providing insights into how these models work and safeguarding them against potential misuse. Furthermore, the leaked system prompt represents valuable intellectual property for Anthropic, and its exposure could potentially impact the company's competitive advantage in the rapidly evolving AI market.10 The unique combination of instructions and guidelines that define Claude's behavior and capabilities is a result of significant research and development efforts. The public availability of this information might allow competitors to gain insights into Anthropic's strategies and potentially replicate or adapt aspects of their approach, thereby eroding some of Anthropic's distinctiveness.
The detailed content of the leaked system prompt offers valuable insights into the design philosophy and priorities that underpin Anthropic's Claude model. The strong emphasis on safety, ethical considerations, and responsible AI behavior is clearly evident in the extensive moderation protocols embedded within the prompt.9 The meticulous instructions aimed at preventing the generation of harmful content, avoiding hate speech and discrimination, and adhering to copyright laws underscore Anthropic's commitment to deploying AI in a manner that minimizes potential risks and aligns with societal values. The prompt also reveals a sophisticated integration of various tools, including web search, code execution via the analysis tool, and artifact generation, to enhance Claude's capabilities and provide a more comprehensive and versatile user experience.6 The detailed instructions on when and how to use these tools indicate a deliberate strategy to augment Claude's core language processing abilities with functionalities that enable it to access real-time information, perform complex computations, and generate diverse forms of output. Moreover, the level of detail in the instructions aimed at shaping Claude's responses, interactions, and adherence to specific guidelines is remarkable.6 From specifying how to handle counting tasks to setting strict rules on copyright and web search citations, the prompt demonstrates a highly granular approach to controlling Claude's behavior and ensuring it aligns with Anthropic's intended operational parameters. This level of meticulousness suggests a significant investment in prompt engineering and a continuous effort to refine the model's performance and reliability across a wide range of scenarios.
The leak of Anthropic's Claude 3.7 Sonnet system prompt provides a unique opportunity to understand the intricate instructions that govern the behavior of this advanced large language model. The analysis of the leaked content reveals a strong emphasis on safety, ethical considerations, and the responsible use of AI, as evidenced by the detailed moderation protocols and copyright protection measures. Furthermore, the prompt showcases a sophisticated design that integrates various tools to enhance Claude's capabilities, offering functionalities such as web search, code execution, and artifact generation. The sheer length and level of detail in the instructions highlight the meticulous approach taken by Anthropic to shape the model's responses and ensure adherence to specific guidelines. While the leak offers valuable insights into Claude's design and priorities, it also raises concerns about potential security risks and the implications for Anthropic's intellectual property. The event underscores the ongoing dialogue within the AI community regarding the balance between transparency, security, and responsible development in the rapidly advancing field of artificial intelligence.