Writer unveils Palmyra X6, a post-trained variant of Z.ai’s GLM-5.2, and upgrades its agentic harness to cut token costs

Writer, an AI tools and agents provider for marketers, announced the release of Palmyra X6, a new flagship model described as a post-training variation on Z.ai’s open-source GLM-5.2. The company positions the model as a deployment-ready alternative aimed at reducing per-token costs for enterprise users.

Writer estimates that, when paired with upgrades to its agentic harness infrastructure, the new model can reduce costs for customers by up to 50% for basic tasks. The company also released significant upgrades to its standard agentic harness, which it says improves efficiency for complex, multi-step tasks while consuming fewer tokens.

Internal research from Writer, cited in the announcement, found that optimizing the harness was often a more reliable way to reduce costs than changing the underlying model. In testing across multiple models, the company reported average cost reductions of 40% from harness adjustments alone. Writer’s CEO May Habib argued that enterprises are prioritizing cost predictability over chasing the latest benchmarks, stating, “They want flattening cost, and it seems like nobody can deliver that.”

Habib also criticized major AI labs for lacking incentives to help enterprises control costs, saying, “The cost explosion here is just unprecedented for customers, and so is the degree to which CIOs are giving up on the labs,” adding that labs “don’t deeply understand how to help an enterprise get benefit from AI.”

Palmyra X6 will be available alongside Writer’s existing model lineup and can also integrate with third-party models imported via Azure or Amazon Bedrock. The new model and harness upgrades are available to Writer clients starting August 13, 2026.