Hermes Agent MCP startup failure? First, check the npx path in Docker

If the Hermes Agent's MCP server fails to start in Docker, don't suspect the MCP configuration is completely wrong. Focus on checking the paths of the npx, npm, node commands in the container. Hermes Agent v0.15.1 fixed the MCP raw command parsing issue in Docker on May 29, 2026. It parses these commands to the /usr/local/bin to prevent the container from starting even though the Node toolchain is present.

This question usually looks like this

You run npx locally, but the Hermes Agent doesn't pull up properly when calling the MCP server on the Docker backend; Sometimes the log only shows MCP connection failures, empty tool lists, or even "quiet failures." Such situations are easily misunderstood as incorrect API keys or incorrect MCP manifest writing; in reality, it may just be that the PATH obtained by processes in the container does not include the location of the node.

When investigating, do three things first

1. First, upgrade the Hermes Agent to v0.15.1 to avoid the known Docker PATH issues from v0.15.0.
2. Enter the container and execute which node, which npm, which npx to confirm the actual path.
3. If you can't upgrade for now, change the bare command in the MCP configuration to an absolute path, for example /usr/local/bin/npx.

If it can start after switching to an absolute path, it basically means the problem is with the PATH. Don't keep drastically changing the MCP parameters. After upgrading, you can restore the configuration to more general bare commands, but you must keep a rollable backup, especially for team shared configurations.

What other situations are not PATH?

If the npx can be found but the MCP still fails, then look at three types of issues: interactive input is needed but the container cannot interact; The environment variables required by the MCP server were not passed into the container; The image lacks runtime dependencies. The recommended order for judgment is: "Can the command be found, dependencies can be started, credentials are complete, and can Hermes connect?" This way, troubleshooting is the fastest and least likely to accidentally delete configurations.