NeqSim 3.13.0

What is NeqSim?

NeqSim is an open-source Java library for thermodynamic fluid properties, phase equilibrium, PVT calculations, and process simulation. It is used to model fluids and process equipment such as separators, compressors, heat exchangers, pipelines, wells, and complete flowsheets.

This release ships both the core NeqSim simulation engine and the MCP server distribution that lets MCP-compatible AI clients call governed NeqSim calculation tools.

What is included in this release

Distribution	Asset	Runtime	Use this when
NeqSim core library	neqsim-3.13.0.jar	Java 17+	You need Java 17 or Python neqsim-python compatibility.
NeqSim core library	neqsim-3.13.0-Java8.jar	Java 8+	You need Java 8 or Python neqsim-python compatibility.
NeqSim MCP server	neqsim-mcp-server-3.13.0-runner.jar	Java 21+	You want VS Code Copilot, Claude Desktop, Cursor, or another MCP client to use NeqSim tools.
NeqSim MCP server checksum	neqsim-mcp-server-3.13.0-runner.jar.sha256	-	You want to verify the downloaded MCP runner jar.
NeqSim MCP server container	ghcr.io/equinor/neqsim-mcp-server:3.13.0	Docker	You want to run the MCP server without installing Java locally.

Install the MCP server

The MCP server gives MCP-compatible LLM clients access to validated thermodynamic and process simulation tools through a governed tool interface.

Jar install (requires Java 21+)

VERSION=3.13.0
curl -fLO "https://github.com/equinor/neqsim/releases/download/v${VERSION}/neqsim-mcp-server-${VERSION}-runner.jar"
curl -fLO "https://github.com/equinor/neqsim/releases/download/v${VERSION}/neqsim-mcp-server-${VERSION}-runner.jar.sha256"
sha256sum -c neqsim-mcp-server-${VERSION}-runner.jar.sha256

Docker install

docker pull ghcr.io/equinor/neqsim-mcp-server:3.13.0

Claude Desktop example

{
  "mcpServers": {
    "neqsim": {
      "command": "java",
      "args": ["-jar", "/path/to/neqsim-mcp-server-3.13.0-runner.jar"]
    }
  }
}

See the MCP Server README for VS Code Copilot, Cursor, Docker, Streamable HTTP, and deployment-profile configuration.

Use the core Java library

Use the release assets above when you need standalone jars. For Maven projects, use the published package dependency:

<dependency>
  <groupId>com.equinor.neqsim</groupId>
  <artifactId>neqsim</artifactId>
  <version>3.13.0</version>
</dependency>

Release notes

GitHub-generated release notes are included with this release and list the commits and pull requests since the previous version.

What's Changed

• cleanup by @asmfstatoil in #2249
• fix: typo cricondebar -> cricondenbar by @asmfstatoil in #2251
• chore: do not call clean display from lib code by @asmfstatoil in #2250
• Fix critical point flash: symmetric eigen solver and Heidemann-Khalil objective by @EvenSol in #2253
• refact: convert example to test by @asmfstatoil in #2252
• EOS update by @EvenSol in #2255
• update mcp by @EvenSol in #2256
• Improve UMR-PRU EOS: fix base constructor, refactor table routing, add docs and regression test by @EvenSol in #2257

Full Changelog: v3.12.1...v3.13.0