Events

CodeCompanion fires User autocmds at points in its lifecycle, so your config can react to a chat opening, a request finishing or a file being edited.

For hooks that can change a chat's state, such as on_before_submit and on_tool_output, see Callbacks.

Consuming an Event

To format a buffer once you've kept an inline edit:

local group = vim.api.nvim_create_augroup("CodeCompanionHooks", {})

vim.api.nvim_create_autocmd({ "User" }, {
  pattern = "CodeCompanionInline*",
  group = group,
  callback = function(request)
    if request.match == "CodeCompanionInlineAccepted" then
      require("conform").format({ bufnr = request.buf })
    end
  end,
})

Event Data

Each event carries a data payload. For CodeCompanionRequestStarted:

{
  buf = 10,
  data = {
    adapter = {
      formatted_name = "Copilot",
      model = "o3-mini-2025-01-31",
      name = "copilot"
    },
    bufnr = 10,
    id = 6107753,
    interaction = "chat"
  },
  event = "User",
  file = "CodeCompanionRequestStarted",
  group = 14,
  id = 30,
  match = "CodeCompanionRequestStarted"
}

CodeCompanionRequestFinished adds a status, such as "success", "error" or "cancelled".

Triggering an Event

To make the chat buffer re-check which tools and slash commands are enabled:

vim.api.nvim_exec_autocmds("User", {
  pattern = "CodeCompanionChatRefreshCache",
})

List of Events

Chat buffer

Event	Fired
CodeCompanionChatCreated	After a chat is created for the first time
CodeCompanionChatOpened	After a chat is opened
CodeCompanionChatHidden	After a chat is hidden
CodeCompanionChatClosed	After a chat is closed for good
CodeCompanionChatSubmitted	After a message is sent
CodeCompanionChatDone	After a response is received
CodeCompanionChatStopped	After a request is stopped
CodeCompanionChatCleared	After a chat is cleared
CodeCompanionChatRestored	After a chat is made editable again, such as when on_before_submit blocks a message
CodeCompanionChatCompacting	When a chat starts compacting its messages
CodeCompanionChatAdapter	After the adapter is set
CodeCompanionChatModel	After the model is set
CodeCompanionChatTitle	After the title is set, with the title in the payload
CodeCompanionChatToolAdded	After a tool is added, with the tool in the payload

Sessions

Event	Fired
CodeCompanionChatSessionSaved	After a chat is saved to disk, with its slug in the payload
CodeCompanionChatSessionRestored	After a session is restored, with its stem in the payload
CodeCompanionChatSessionsChanged	After a session is written or deleted

ACP

Event	Fired
CodeCompanionACPConnected	After the connection is authenticated and ready
CodeCompanionACPSessionPre	After authentication, before a session starts, so you can change the connection, such as adding MCP servers
CodeCompanionACPSessionPost	After a session starts
CodeCompanionACPChatRestored	After a session is restored
CodeCompanionACPCommandsUpdate	After an agent's commands are loaded, with the commands in the payload
CodeCompanionChatACPConfigChanged	After an agent's configuration options change, with the config_options in the payload

CLI

Event	Fired
CodeCompanionCLICreated	After a CLI buffer is created for the first time
CodeCompanionCLIOpened	After a CLI buffer is opened
CodeCompanionCLIHidden	After a CLI buffer is hidden
CodeCompanionCLIClosed	After a CLI buffer is closed
CodeCompanionCLISent	After text is sent to a CLI buffer
CodeCompanionCLISubmitted	When the agent accepts a prompt, however it was typed
CodeCompanionCLIDone	When the agent finishes a turn
CodeCompanionCLIApprovalRequested	When the agent is waiting on you, with a message in the payload
CodeCompanionCLIApprovalFinished	When the agent resumes after waiting

The last four need agent hooks.

Requests

Event	Fired
CodeCompanionRequestStarted	At the start of a request, or a CLI agent's turn when hooks are set up
CodeCompanionRequestStreaming	At the start of a streaming request
CodeCompanionRequestFinished	At the end of a request, or a CLI agent's turn when hooks are set up
CodeCompanionInlineStarted	At the start of an inline request
CodeCompanionInlineFinished	At the end of an inline request, before its edits are reviewed
CodeCompanionInlineAccepted	When you keep any of an inline request's edits

Tools

Event	Fired
CodeCompanionToolsStarted	When a batch of tools starts
CodeCompanionToolsFinished	When a batch of tools finishes, is stopped or is cancelled
CodeCompanionToolStarted	When a tool starts
CodeCompanionToolFinished	When a tool finishes
CodeCompanionToolApprovalRequested	When a tool asks for approval
CodeCompanionToolApprovalFinished	When you approve or reject a tool
CodeCompanionToolQuestionAsked	When a tool asks you a question
CodeCompanionToolQuestionAnswered	When you answer or skip a question
CodeCompanionToolsJudgeStarted	When the judge starts vetting a tool call
CodeCompanionToolsJudgeFinished	When the judge returns its verdict

Files and diffs

Event	Fired
CodeCompanionFileEdited	After a file is edited or created, with the path and the tool that changed it in the payload
CodeCompanionDiffHunkChanged	After moving to the next or previous hunk in a diff

MCP

Event	Fired
CodeCompanionMCPServerStart	When a server starts
CodeCompanionMCPServerReady	When a server is ready for requests
CodeCompanionMCPServerToolsLoaded	When a server's tools are loaded
CodeCompanionMCPServerClosed	When a server closes