feat: Add nvim-cmp integration

README.md

@@ -501,6 +501,30 @@ Requires [fzf-lua](https://github.com/ibhagwan/fzf-lua) plugin to be installed.
 
 </details>
 
+<details>
+<summary>nvim-cmp integration</summary>
+
+Requires [nvim-cmp](https://github.com/hrsh7th/nvim-cmp) plugin to be installed (and properly configured).
+
+```lua
+-- Registers copilot-chat source and enables it for copilot-chat filetype (so copilot chat window)
+require("CopilotChat.integrations.cmp").setup()
+
+-- You might also want to disable default <tab> complete mapping for copilot chat when doing this
+require('CopilotChat').setup({
+  mappings = {
+    complete = {
+      insert = '',
+    },
+  },
+  -- rest of your config
+})
+```
+
+![image](https://github.com/CopilotC-Nvim/CopilotChat.nvim/assets/5115805/063fc99f-a4b2-4187-a065-0fdd287ebee2)
+
+</details>
+
 ## Roadmap (Wishlist)
 
 - Use indexed vector database with current workspace for better context selection

lua/CopilotChat/integrations/cmp.lua

@@ -0,0 +1,45 @@
+local cmp = require('cmp')
+local chat = require('CopilotChat')
+
+local Source = {}
+
+function Source:get_trigger_characters()
+  return { '@', '/' }
+end
+
+function Source:complete(params, callback)
+  local items = {}
+  local prompts_to_use = chat.prompts()
+
+  if params.completion_context.triggerCharacter == '/' then
+    for name, _ in pairs(prompts_to_use) do
+      items[#items + 1] = {
+        label = '/' .. name,
+      }
+    end
+  else
+    items[#items + 1] = {
+      label = '@buffers',
+    }
+
+    items[#items + 1] = {
+      label = '@buffer',
+    }
+  end
+
+  callback({ items = items })
+end
+
+local M = {}
+
+--- Setup the nvim-cmp source for copilot-chat window
+function M.setup()
+  cmp.register_source('copilot-chat', Source)
+  cmp.setup.filetype('copilot-chat', {
+    sources = {
+      { name = 'copilot-chat' },
+    },
+  })
+end
+
+return M