ChatGPT: Local Government AI 'zevo' Launches Three New GPT-5.6 Models (sol/terra/luna) Starting July 13, 2026

Shift Plus Co., Ltd. (President: Hiroya Nakao; Head Office: 3070-1 Miyamachi, Miyakonojo City, Miyazaki Prefecture; Headquarters: 2-1-1 Edobori, Nishi-ku, Osaka City, Osaka Prefecture, Edobori Center Building 8F; hereinafter 'Shift Plus') announces the rollout of three new AI models—GPT-5.6-sol, GPT-5.6-terra, and GPT-5.6-luna—to all municipalities using 'Local Government AI zevo,' a system co-developed with Miyakonojo City. This platform enables secure use of generative AI tools such as ChatGPT, Claude, and Gemini within local governments' LGWAN environments.

Three New Models Added: GPT-5.6-sol, GPT-5.6-terra, and GPT-5.6-luna – Expanding AI Model Availability

The 'Local Government AI zevo' platform already supports three major generative AI series: ChatGPT, Claude, and Gemini. Now, new models under the ChatGPT series are being introduced.

GPT-5.6, launching on the platform, is OpenAI’s latest chat-optimized model. It features high reasoning capabilities and a large context window, enabling use across a wide range of tasks—from simple inquiries to complex document creation.

The series includes three distinct models—sol, terra, and luna—each optimized for different combinations of performance, speed, and cost, allowing municipalities to select the best fit for their specific needs.

Key features of each model are as follows:

1. GPT-5.6-sol Features

GPT-5.6-sol is the flagship model in OpenAI’s GPT-5.6 series.

It excels in complex reasoning and advanced document generation, making it ideal for high-difficulty tasks.

It achieved industry-leading scores in coding benchmarks and supports logical document structuring, detailed research, and analytical tasks.

Main features:

- High reasoning power: Achieves top scores in AI reasoning tests, capable of handling complex ordinance interpretations and legal research.

- Advanced research and analysis: Processes multiple documents and long-form content simultaneously, enabling cross-referencing, argument synthesis, comparison, and key-point extraction.

GPT-5.6-sol

Knowledge cutoff: June 2026

Context window: Input 920K, Output 128K

Region: EU

2. GPT-5.6-terra Features

GPT-5.6-terra is the mid-tier model in the GPT-5.6 series.

Designed for a balance between performance and cost, it supports a wide range of tasks—from daily operations to moderately complex processing.

It efficiently assists with administrative guidance, citizen inquiries, document summarization, and other routine staff duties.

Main features:

- Balanced performance and cost: Offers high versatility at a lower cost than the sol model, suitable for diverse municipal operations.

- Broad task coverage: Handles inquiries, summaries, and document creation with consistent efficiency.

GPT-5.6-terra

Knowledge cutoff: June 2026

Context window: Input 920K, Output 128K

Region: EU

3. GPT-5.6-luna Features

GPT-5.6-luna is the lightest model in the GPT-5.6 series.

Optimized for low-cost, high-volume processing, it is ideal for handling routine inquiries and batch document processing.

As the most affordable model in the series, it is perfect for automating repetitive, standardized tasks efficiently.

Main features:

- High cost efficiency: The most cost-effective model in the GPT-5.6 series, enabling low-cost processing of high-volume, repetitive requests.

- Fast response speed: Delivers the fastest responses in the series, smoothly handling large volumes of standardized queries.

GPT-5.6-luna

Knowledge cutoff: June 2026

Context window: Input 920K, Output 128K

Region: EU

※ By default, all models are set to 'disabled.' Organizational administrators must enable usage permissions for each model.

Local Government AI zevo: Connecting, Expanding, and Becoming More Convenient

Business Chat Tool LGTalk Now Available

Customers subscribing to 'Local Government AI zevo' will receive employee-number-matched accounts for LGTalk, a secure business chat tool. LGTalk emphasizes security features such as file sanitization and allows direct access to generative AI (zevo) within chat.

A trial version supporting up to 10 accounts is also available.

Integration with eRex Now Possible

The platform now supports integration with 'eRex,' an LGWAN-exclusive AI-powered speech recognition and transcription tool. A one-month free trial for eRex is also offered.

For inquiries, please contact us.

We appreciate your continued support for Shift Plus and 'Local Government AI zevo.'

About Shift Plus Co., Ltd.

Founded in December 2006 in Nishi-ku, Osaka City, Shift Plus has its headquarters in Osaka and its head office in Miyakonojo City, Miyazaki Prefecture, with 27 branch offices across Japan. The company specializes in developing, maintaining, and consulting on IT systems for local governments, as well as outsourcing services and web system design and implementation. It has independently developed 'LedgHOME,' a hometown tax donation management system, and manages end-to-end hometown tax operations. As of August 2025, over 520 municipalities from Hokkaido to Kyushu have adopted the system, which manages approximately 50% of all hometown tax donations nationwide.