The *Situate AI Guidebook* is a co-designed toolkit aimed at supporting multi-stakeholder early-stage deliberations around public sector AI proposals. The guidebook synthesizes critical considerations identified through co-design activities and semi-structured interviews with public sector agency workers and community advocates. These considerations are structured into four main topics: goals and intended use, societal and legal considerations, data and modeling constraints, and organizational governance factors. The guidebook provides a set of 132 deliberation questions to facilitate conversations among stakeholders, ensuring that key issues are discussed before moving forward with AI projects. The design principles of the guidebook emphasize reflexive deliberation and practicality, aiming to address the challenges and needs of public sector agencies in making informed decisions about AI tool development and deployment. The toolkit is intended to be adaptable to different organizational contexts and to promote meaningful improvements in decision-making processes. The paper also discusses the implications for future research and the potential for expanding the guidebook to engage community members in the deliberation process.The *Situate AI Guidebook* is a co-designed toolkit aimed at supporting multi-stakeholder early-stage deliberations around public sector AI proposals. The guidebook synthesizes critical considerations identified through co-design activities and semi-structured interviews with public sector agency workers and community advocates. These considerations are structured into four main topics: goals and intended use, societal and legal considerations, data and modeling constraints, and organizational governance factors. The guidebook provides a set of 132 deliberation questions to facilitate conversations among stakeholders, ensuring that key issues are discussed before moving forward with AI projects. The design principles of the guidebook emphasize reflexive deliberation and practicality, aiming to address the challenges and needs of public sector agencies in making informed decisions about AI tool development and deployment. The toolkit is intended to be adaptable to different organizational contexts and to promote meaningful improvements in decision-making processes. The paper also discusses the implications for future research and the potential for expanding the guidebook to engage community members in the deliberation process.