feat(extensions): adapt CodeCompanion extension for v19 compatibility

[bahaaza]

Summary

Migrate the CodeCompanion extension to support CodeCompanion v19's breaking API changes while maintaining the same user-facing behavior.

Motivation

CodeCompanion v19 introduced several breaking changes to its tool, variable, and image APIs. This PR updates all four CodeCompanion extension modules to work with the new API surface.

Changes

Tool Config Structure (tools.lua)

• callback = { table } → callback = function() return { table } end
• v19's Tools.resolve() requires callback to be a function, not a table.

Tool cmds Handlers (tools.lua, core.lua)

• Handler signature: (agent, args, _, output_handler) → (self, action, opts)
• Output callback now accessed via opts.output_cb instead of the 4th positional arg.

Tool Output Handlers (core.lua)

• Success/error signature: (self, agent, cmd, data) → (self, data, meta)
• Chat object accessed via meta.tools.chat instead of the agent parameter.

Variables → Editor Context (variables.lua)

• config.interactions.chat.variables → config.interactions.chat.editor_context
• Cleanup logic now uses key prefix (mcp:) instead of the custom id field.
• Removed unused id field from registrations.

Image Handling (variables.lua, slash_commands.lua)

• require("codecompanion.interactions.chat.helpers").add_image(chat, img) → chat:add_image_message(img)
• All references to the removed helpers module have been eliminated.

Group System Prompts (tools.lua)

• system_prompt = function(self) → system_prompt = function(group_config, ctx)
• Updated all three system_prompt functions (static group, individual tools, dynamic server groups).

Files Modified

• lua/mcphub/extensions/codecompanion/tools.lua
• lua/mcphub/extensions/codecompanion/core.lua
• lua/mcphub/extensions/codecompanion/variables.lua
• lua/mcphub/extensions/codecompanion/slash_commands.lua

Testing

• All 135 existing tests pass (make test)
• Code formatted with stylua (make format)
• No CodeCompanion-specific integration tests exist in the repo currently; changes were verified by tracing the v19 source code for each API contract.

[powerman]

Works for me, thanks!

[NarongOk]

Would like to see this merged!!!

[EvgeniyRRU]

Yes, we're really looking forward to seeing it happen.

[HendrikPetertje]

Can this be merged pretty please @ravitemer?

[zelch]

I can confirm that this seems to work pretty well on my system.

[augustocdias]

The maintainer isn't active on github for quite a while already... Perhaps its time to consider a fork to keep the project going :/

[bahaaza]

Well, you can use my fork for the meanwhile, I'll be using mcphub for a while, codecompanion has built in support for mcps but its not as mature as mcphub.

[zelch]

@bahaaza I don't suppose you have any interest in forking the mcp-hub server as well?

Locally I updated the @modelcontextprotocol/sdk dependency to something a bit more current, and oauth support works a ton better.

(I'd do it myself, but there's an annoying amount of paperwork involved with my employer, and bumping the dependency is really the only change.)

[LyndonArmitage]

The maintainer isn't active on github for quite a while already... Perhaps its time to consider a fork to keep the project going :/

Not a bad idea.

In the meantime, @powerman on an issue highlighted how you can use the lazy-local-patcher.nvim plugin, if you're using Lazy, to apply a patch while waiting for something to be merged.

For me this was as simple as adding the file lua/plugins/lazy-local-patcher.lua to my NeoVim config directory containing:

return {
    "polirritmico/lazy-local-patcher.nvim",
    config = true,
    ft = "lazy", -- for lazy loading
}

And then adding a patch file to patches/mcphub.nvim/ within my NeoVim configuration folder containing a patch for this issue, which you can get via appending .patch to the URL: https://github.com/ravitemer/mcphub.nvim/pull/279.patch

[jamietanna]

Alternatively:

# via https://www.jvt.me/posts/2019/01/19/git-ref-github-pull-requests/
# in the directory that you have `mcphub.nvim` checked out
git config remote.origin.fetch '+refs/pull/*:refs/remotes/origin/pull/*'

Then:

return {
  "ravitemer/mcphub.nvim",
  branch = "pull/279/merge"
}

[jingyi-zhao-01]

when can this PR be merged

[HendrikPetertje]

Hate to ask this and huge respect to the developer for investing their time in making this excellent plugin.
It's super quiet in this repo and without the above in mcphub doesn't really work in codecompanion on any recent versions.

@ravitemer do you need help maintaining this plugin?