with immunotherapy, can directly cause tumor cell death in an immunogenic manner and work synergistically with immunotherapy to potentiate the immune response. [1] The therapeutic efficiency of PTI is often modest, owing to the inadequate immunogenicity of tumor cells and poor immune response. [2] PTT triggers immunogenic cell death (ICD) by releasing damage-associated molecular patterns (DAMPs) to induce dendritic cell (DC) maturation and increase T cell infiltration, thereby initiating the antitumor immune responses. [3] Evidence from recent studies has validated the pivotal role of reactive oxygen species (ROS) production and endoplasmic reticulum stress for the exposure of DAMPs. [3b,4] Therefore, the development of photothermal agents (PTAs) with effective ROS production capacities provides a promising direction for improving the immunogenicity of tumor cells. [5] The antioxidant system, mainly consisting of glutathione (GSH), can reduce ROS levels and lead to immunosuppression and attenuation of antitumor efficacy. [6] Therefore, it is imperative to exploit GSH-consuming PTAs to leverage the ICD effect of PTT and to serve as adjuvants to elevate immune responsiveness.Second near-infrared (NIR-II) (1000-1350 nm) PTAs, based on a variety of inorganic and organic materials, have recently attracted considerable attention owing to their advantages of deep tissue penetration, high maximum permission energy, and good sensitivity and signal-noise ratio. [7] So far, NIR-II PTAs have been explored in combination with immunoadjuvant therapy, genome editing-based therapy, or immune checkpoint blockade therapy to achieve effective PTI. [8] Among them, inorganic NIR-II PTAs, consisting of non-metallic materials, noble metals, and transition metal materials, exhibit good photothermal effects as well as tunable and controllable morphologies, but suffer from potential leakage and weak biodegradability. [9] Organic NIR-II PTAs, containing small-molecule photosensitizers, [10] semiconducting polymers, [11] and organic radicals, [12] exhibit low side-effects and good biocompatibility, [7] but sophisticated design and complex production requirements often hinder their applications. [10b,13] An organic metal is an organic material that possesses the electrical, magnetic, and optical properties of a metal while retaining the degradability, biocompatibility, adjustability, and processability associated Although photothermal immunotherapy (PTI) is a compelling strategy for tumor therapy, the development of promising photothermal agents to overcome the insufficient immunogenicity of tumor cells and the poor immune response encountered in PTI is still challenging. Herein, commercial small-molecule-based organic metal adjuvants (OMAs) are presented, with second near-infrared photoacoustic and photothermal properties as well as the ability to perturb redox homeostasis to potentiate immunogenicity and immune responsiveness. OMAs, assembled from charge-transfer complexes and characterized by a broad substrate scope, high accessibil...