--- title: "FastChat vs service-fabric" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/lm-sys-fastchat-vs-microsoft-service-fabric" tools: ["lm-sys-fastchat", "microsoft-service-fabric"] --- # FastChat vs service-fabric *GraphCanon updated Sep 20, 2026* ## Verdict Pick FastChat if fastChat is an open-source platform for training, serving, and evaluating large language models, including Vicuna, and supports Chatbot Arena, a platform for LLM evaluations with human feedback; pick service-fabric if service Fabric is an infrastructure platform for managing scalable and distributed microservices and stateful applications in cloud environments with C++ support. [FastChat](https://github.com/lm-sys/FastChat) reports 40k GitHub stars, 4.8k forks, and 1.0k open issues, last pushed May 1, 2026. [service-fabric](https://docs.microsoft.com/en-us/azure/service-fabric/) has 3.1k stars, 401 forks, and 847 open issues, last pushed Sep 17, 2026. Figures are from public GitHub metadata via [FastChat's repository](https://github.com/lm-sys/FastChat) and [service-fabric's repository](https://github.com/microsoft/service-fabric). | | [FastChat](/tools/lm-sys-fastchat.md) | [service-fabric](/tools/microsoft-service-fabric.md) | | --- | --- | --- | | Tagline | An open platform for training, serving, and evaluating large language models | A distributed systems platform for managing cloud-native microservices and stateful applications. | | Stars | 39,536 | 3,065 | | Forks | 4,774 | 401 | | Open issues | 1,043 | 847 | | Language | Python | C++ | | Adopt for | FastChat is an open-source platform for training, serving, and evaluating large language models, including Vicuna, and supports Chatbot Arena, a platform for LLM evaluations with human feedback. | Service Fabric is an infrastructure platform for managing scalable and distributed microservices and stateful applications in cloud environments with C++ support. | | Persona | - | - | | Runtime | - | - | | License | Apache-2.0 | MIT | | Categories | Evaluation & Observability, Inference & Serving, LLM Frameworks, Model Training | Inference & Serving, Model Training | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [FastChat](/tools/lm-sys-fastchat.md) | [service-fabric](/tools/microsoft-service-fabric.md) | | --- | --- | --- | | Maintenance | Slowing (36%) | Very active (96%) | | Days since push | 140d | 1d | | Open issues (now) | 1.0k | 847 | | Stars delta | +19 (30d) | +4 (30d) | | Open issues delta | +5 (30d) | +2 (30d) | | Full report | [trust report](/tools/lm-sys-fastchat/trust.md) | [trust report](/tools/microsoft-service-fabric/trust.md) | ## Decision facts: FastChat - **Adopt for:** FastChat is an open-source platform for training, serving, and evaluating large language models, including Vicuna, and supports Chatbot Arena, a platform for LLM evaluations with human feedback. ## Decision facts: service-fabric - **Requirements:** Min 32 GB RAM; Requires Docker - **Adopt for:** Service Fabric is an infrastructure platform for managing scalable and distributed microservices and stateful applications in cloud environments with C++ support. ## Choose when ### Choose FastChat if… - FastChat is primarily Python; service-fabric is C++. - License: FastChat is Apache-2.0, service-fabric is MIT. - Tags unique to FastChat: chatbot arena, llm-evaluation, multi-model serving, openai-compatible apis. - Also covers Evaluation & Observability, LLM Frameworks. - When you need a platform that supports both training and evaluation of large language models, such as Vicuna, and you want to leverage human feedback for model evaluation. ### Choose service-fabric if… - service-fabric is primarily C++; FastChat is Python. - License: service-fabric is MIT, FastChat is Apache-2.0. - Requirements: Min 32 GB RAM; Requires Docker. - Tags unique to service-fabric: cloud-computing, cloud-native, containers, distributed-systems. - When you need to deploy and manage containerized services that are both stateless and stateful, leveraging advanced features of a robust distributed systems platform ## When NOT to use FastChat - If you are looking for a platform that focuses solely on model training without serving or evaluation capabilities, FastChat offers a comprehensive suite that might be more than you need. - If your project does not require human feedback for model evaluation, FastChat's integration with Chatbot Arena might be an unnecessary feature. - If you are working with proprietary or closed-source models, FastChat's open-source nature and reliance on open-source models like Vicuna might not align with your project requirements. ## When NOT to use service-fabric - When building small applications that can be managed using simpler deployment tools, as Service Fabric may introduce unnecessary complexity and require more powerful hardware - If preferred development language is not C++ since integration support focuses heavily on this programming language, leading to potentially less streamlined operations for other languages ## Common questions ### What is the difference between FastChat and service-fabric? FastChat: An open platform for training, serving, and evaluating large language models. service-fabric: A distributed systems platform for managing cloud-native microservices and stateful applications.. See the comparison table for live GitHub stats and shared categories. ### When should I choose FastChat over service-fabric? Choose FastChat over service-fabric when FastChat is primarily Python; service-fabric is C++; License: FastChat is Apache-2.0, service-fabric is MIT; Tags unique to FastChat: chatbot arena, llm-evaluation, multi-model serving, openai-compatible apis; Also covers Evaluation & Observability, LLM Frameworks; When you need a platform that supports both training and evaluation of large language models, such as Vicuna, and you want to leverage human feedback for model evaluation. ### When should I choose service-fabric over FastChat? Choose service-fabric over FastChat when service-fabric is primarily C++; FastChat is Python; License: service-fabric is MIT, FastChat is Apache-2.0; Requirements: Min 32 GB RAM; Requires Docker; Tags unique to service-fabric: cloud-computing, cloud-native, containers, distributed-systems; When you need to deploy and manage containerized services that are both stateless and stateful, leveraging advanced features of a robust distributed systems platform. ### When should I avoid FastChat? If you are looking for a platform that focuses solely on model training without serving or evaluation capabilities, FastChat offers a comprehensive suite that might be more than you need. If your project does not require human feedback for model evaluation, FastChat's integration with Chatbot Arena might be an unnecessary feature. If you are working with proprietary or closed-source models, FastChat's open-source nature and reliance on open-source models like Vicuna might not align with your project requirements. ### When should I avoid service-fabric? When building small applications that can be managed using simpler deployment tools, as Service Fabric may introduce unnecessary complexity and require more powerful hardware If preferred development language is not C++ since integration support focuses heavily on this programming language, leading to potentially less streamlined operations for other languages ### Is FastChat or service-fabric more popular on GitHub? FastChat has more GitHub stars (39,536 vs 3,065). Stars measure visibility, not whether either tool fits your constraints. ### Are FastChat and service-fabric open source? Yes - both are open-source projects on GitHub (FastChat: Apache-2.0, service-fabric: MIT). ### Where can I find alternatives to FastChat or service-fabric? GraphCanon lists graph-backed alternatives at [FastChat alternatives](/tools/lm-sys-fastchat/alternatives) and [service-fabric alternatives](/tools/microsoft-service-fabric/alternatives) ([FastChat markdown twin](/tools/lm-sys-fastchat/alternatives.md), [service-fabric markdown twin](/tools/microsoft-service-fabric/alternatives.md)), ranked by typed relationship edges rather than popularity votes. ### Is there a machine-readable version of this comparison? Yes. The markdown twin at [this comparison](/compare/lm-sys-fastchat-vs-microsoft-service-fabric.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, FastChat or service-fabric? FastChat: Slowing. service-fabric: Very active. Compare maintenance labels, days since push, and release cadence in the trust section below - stars alone do not measure maintenance. ### Where are the full trust reports for FastChat and service-fabric? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [FastChat trust report](/tools/lm-sys-fastchat/trust); [service-fabric trust report](/tools/microsoft-service-fabric/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=lm-sys-fastchat`](/api/graphcanon/graph?tool=lm-sys-fastchat) - LLM index: [/llms.txt](/llms.txt) - Full corpus: [/llms-full.txt](/llms-full.txt) _GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_