Upgrade the MCP bridge

Move the emisar-mcp bridge on each workstation to a new release.

To upgrade runners instead, see Upgrade runners.

Find the version you run#

The AI agents page shows the bridge version each key last reported. A cloud client leaves this value blank because it has no bridge, and nothing to upgrade. On the workstation, run:

$ emisar-mcp --version

One workstation runs one bridge, shared by every client on it. You upgrade once per machine, not once per client.

Compatibility status#

emisar compares each reported version against two published numbers: the minimum we still support, and the release we recommend you run.

• — outdated is above the minimum but behind what we recommend. It keeps working. The console shows a version chip, and nothing else changes.
• — unsupported is below the minimum. The key shows this in place of its usual activity. It still connects today, but that is not a promise. Upgrade it.

The version is self-reported, so treat it as housekeeping and never as a security control. Your policies and its key decide what a bridge may do.

Upgrade your runners and bridges in the same pass. For which versions work together, see compatibility and deprecation.

Upgrade a bridge#

Run the installer on each workstation. It downloads the new binary next to the current one, authenticates the signed checksum metadata, checks the archive and the version it reports, keeps a copy of the old binary, and only then swaps them. If any step fails, it puts everything back.

# replaces the emisar-mcp binary in place
$ curl -fsSL https://emisar.dev/install-mcp.sh | sudo bash

# confirm the new version
$ emisar-mcp --version

PS> irm https://emisar.dev/install-mcp.ps1 | iex

# confirm the new version
PS> emisar-mcp --version

# replaces the emisar-mcp binary in place
$ curl -fsSL https://emisar.dev/install-mcp.sh | sudo bash

# confirm the new version
$ emisar-mcp --version

• — Client config and API key are untouched. The installer replaces only the binary. An emisar entry already in a client config is left alone.
• — Every copy is replaced. On macOS and Linux the installer updates the bridge in both ~/.local/bin and /usr/local/bin when it finds a copy in each, so no client keeps launching an old one. Windows keeps one copy, in %LOCALAPPDATA%\Programs\Emisar\bin.
• — A running client keeps the binary it already loaded. The client starts the bridge as a child process, so replacing the file on disk does not change the one already running. Restart the client to pick up the new one.
• — Then check it from the client. Ask the agent to list your runners. An answer means the client is running the new bridge. The version command only checks the binary on disk.

Manage agents & keys covers the bridge's key handling and its version chip.

Return to a known-good release#

Going back is the same installer with the version you were on. Restart the client and check it the same way.

$ curl -fsSL https://emisar.dev/install-mcp.sh \
    | sudo bash -s -- --version <known-good-version>

PS> & ([scriptblock]::Create((irm https://emisar.dev/install-mcp.ps1))) `
    -Version <known-good-version>

$ curl -fsSL https://emisar.dev/install-mcp.sh \
    | sudo bash -s -- --version <known-good-version>

Only immutable releases with signed checksum metadata install. A draft, changing, or older unsigned release is refused.