diff --git a/greeptchat/__init__.py b/greeptchat/__init__.py
new file mode 100644
index 0000000..f9ebd24
--- /dev/null
+++ b/greeptchat/__init__.py
@@ -0,0 +1,5 @@
+from .greeptchat import GreeptChat
+
+
+async def setup(bot):
+    await bot.add_cog(GreeptChat(bot))
diff --git a/greeptchat/greeptchat.py b/greeptchat/greeptchat.py
new file mode 100644
index 0000000..12b7cf0
--- /dev/null
+++ b/greeptchat/greeptchat.py
@@ -0,0 +1,255 @@
+import aiohttp
+import discord
+from redbot.core import commands, Config, checks
+from redbot.core.bot import Red
+
+
+class APIKeyModal(discord.ui.Modal):
+    def __init__(self, config):
+        super().__init__(title="GreenPT API Key")
+        self.config = config
+        self.key_input = discord.ui.TextInput(
+            label="API Key",
+            style=discord.TextStyle.short,
+            placeholder="Paste your GreenPT API key here",
+            required=True,
+        )
+        self.add_item(self.key_input)
+
+    async def on_submit(self, interaction: discord.Interaction):
+        await self.config.api_key.set(self.key_input.value)
+        await interaction.response.send_message("API key saved.", ephemeral=True)
+
+
+class GreeptChat(commands.Cog):
+    """AI chat via the GreenPT API. Set a chat channel or get responses when pinged."""
+
+    BASE_URL = "https://greenpt.com/v1"
+
+    def __init__(self, bot: Red):
+        self.bot = bot
+        self.session: aiohttp.ClientSession | None = None
+        self.config = Config.get_conf(self, identifier=987654321)
+        self.config.register_guild(
+            enabled=True,
+            chat_channel=None,
+            model="gemma4",
+            temperature=0.7,
+            system_prompt="You are a helpful assistant.",
+            question_mode=False,
+        )
+        self.config.register_global(api_key=None)
+        self.history: dict[int, list[dict]] = {}
+
+    async def cog_load(self):
+        self.session = aiohttp.ClientSession()
+
+    async def cog_unload(self):
+        if self.session:
+            await self.session.close()
+
+    # ---------------------------------------------------------------------------
+    # Listeners
+    # ---------------------------------------------------------------------------
+
+    @commands.Cog.listener()
+    async def on_message(self, message: discord.Message):
+        if message.author.bot:
+            return
+        if not isinstance(message.channel, discord.TextChannel):
+            return
+
+        guild = message.guild
+        if guild is None:
+            return
+
+        enabled = await self.config.guild(guild).enabled()
+        if not enabled:
+            return
+
+        api_key = await self.config.api_key()
+        if not api_key:
+            return
+
+        chat_channel_id = await self.config.guild(guild).chat_channel()
+        question_mode = await self.config.guild(guild).question_mode()
+
+        is_chat_channel = chat_channel_id and message.channel.id == chat_channel_id
+        is_ping = self.bot.user in message.mentions
+
+        if not is_chat_channel and not is_ping:
+            return
+
+        content = message.content
+        if is_ping:
+            for mention in (f"<@{self.bot.user.id}>", f"<@!{self.bot.user.id}>"):
+                content = content.replace(mention, "").strip()
+
+        if not content:
+            return
+
+        if question_mode and not content.rstrip().endswith("?"):
+            if is_ping:
+                await message.reply("Question mode is on — messages must end with **?**.")
+            return
+
+        async with message.channel.typing():
+            reply = await self._chat(guild, message.channel.id, content)
+
+        if reply is None:
+            await message.reply("No response from GreenPT.")
+            return
+
+        if len(reply) <= 2000:
+            await message.reply(reply)
+        else:
+            chunks = [reply[i : i + 2000] for i in range(0, len(reply), 2000)]
+            for chunk in chunks:
+                await message.reply(chunk)
+
+    # ---------------------------------------------------------------------------
+    # API
+    # ---------------------------------------------------------------------------
+
+    async def _chat(self, guild: discord.Guild, channel_id: int, user_msg: str) -> str | None:
+        api_key = await self.config.api_key()
+        if not api_key or not self.session:
+            return None
+
+        model = await self.config.guild(guild).model()
+        temperature = await self.config.guild(guild).temperature()
+        system_prompt = await self.config.guild(guild).system_prompt()
+
+        key = (guild.id, channel_id)
+        if key not in self.history:
+            self.history[key] = []
+
+        self.history[key].append({"role": "user", "content": user_msg})
+
+        messages = [{"role": "system", "content": system_prompt}] + self.history[key][-20:]
+
+        payload = {
+            "model": model,
+            "messages": messages,
+            "temperature": temperature,
+        }
+
+        try:
+            async with self.session.post(
+                f"{self.BASE_URL}/chat/completions",
+                json=payload,
+                headers={
+                    "Authorization": f"Bearer {api_key}",
+                    "Content-Type": "application/json",
+                },
+                timeout=aiohttp.ClientTimeout(total=60),
+            ) as resp:
+                if resp.status != 200:
+                    body = await resp.text()
+                    return f"API error {resp.status}: {body[:300]}"
+                data = await resp.json()
+        except Exception as exc:
+            return f"Request failed: {exc}"
+
+        try:
+            reply = data["choices"][0]["message"]["content"]
+        except (KeyError, IndexError):
+            return "Unexpected API response."
+
+        self.history[key].append({"role": "assistant", "content": reply})
+
+        if len(self.history[key]) > 40:
+            self.history[key] = self.history[key][-20:]
+
+        return reply
+
+    # ---------------------------------------------------------------------------
+    # Commands
+    # ---------------------------------------------------------------------------
+
+    greept = commands.Group("greept", "GreenPT chat settings.", guild_only=True)
+
+    @greept.command(name="setkey")
+    @checks.is_owner()
+    async def greept_setkey(self, ctx: commands.Context):
+        """Set the GreenPT API key (opens a private modal)."""
+        await ctx.send_modal(APIKeyModal(self.config))
+
+    @greept.command(name="toggle")
+    async def greept_toggle(self, ctx: commands.Context):
+        """Toggle the cog on or off for this server."""
+        current = await self.config.guild(ctx.guild).enabled()
+        await self.config.guild(ctx.guild).enabled.set(not current)
+        state = "enabled" if not current else "disabled"
+        await ctx.send(f"GreeptChat **{state}** for this server.")
+
+    @greept.command(name="channel")
+    async def greept_channel(self, ctx: commands.Context, channel: discord.TextChannel | None = None):
+        """Set the dedicated chat channel. Omit to clear."""
+        if channel is None:
+            await self.config.guild(ctx.guild).chat_channel.set(None)
+            await ctx.send("Chat channel cleared.")
+        else:
+            await self.config.guild(ctx.guild).chat_channel.set(channel.id)
+            await ctx.send(f"Chat channel set to {channel.mention}.")
+
+    @greept.command(name="model")
+    async def greept_model(self, ctx: commands.Context, model: str):
+        """Set the model (e.g. gemma4, green-l, green-r)."""
+        await self.config.guild(ctx.guild).model.set(model)
+        await ctx.send(f"Model set to **{model}**.")
+
+    @greept.command(name="temp")
+    async def greept_temp(self, ctx: commands.Context, temperature: float):
+        """Set the temperature (0.0 - 2.0)."""
+        if not 0.0 <= temperature <= 2.0:
+            await ctx.send("Must be between 0.0 and 2.0.")
+            return
+        await self.config.guild(ctx.guild).temperature.set(temperature)
+        await ctx.send(f"Temperature set to **{temperature}**.")
+
+    @greept.command(name="system")
+    async def greept_system(self, ctx: commands.Context, *, prompt: str):
+        """Set the system prompt."""
+        await self.config.guild(ctx.guild).system_prompt.set(prompt)
+        await ctx.send("System prompt updated.")
+
+    @greept.command(name="question")
+    async def greept_question(self, ctx: commands.Context):
+        """Toggle question mode (messages must end with ?)."""
+        current = await self.config.guild(ctx.guild).question_mode()
+        await self.config.guild(ctx.guild).question_mode.set(not current)
+        state = "ON" if not current else "OFF"
+        await ctx.send(f"Question mode **{state}**.")
+
+    @greept.command(name="clear")
+    async def greept_clear(self, ctx: commands.Context):
+        """Clear conversation history for this channel."""
+        key = (ctx.guild.id, ctx.channel.id)
+        self.history.pop(key, None)
+        await ctx.send("History cleared for this channel.")
+
+    @greept.command(name="settings")
+    async def greept_settings(self, ctx: commands.Context):
+        """Show current settings."""
+        cfg = self.config.guild(ctx.guild)
+        enabled = await cfg.enabled()
+        chat_channel = await cfg.chat_channel()
+        model = await cfg.model()
+        temp = await cfg.temperature()
+        sys_prompt = await cfg.system_prompt()
+        q_mode = await cfg.question_mode()
+        has_key = await self.config.api_key() is not None
+
+        channel_str = f"<#{chat_channel}>" if chat_channel else "None"
+
+        embed = discord.Embed(title="GreeptChat Settings", color=await ctx.embed_color())
+        embed.add_field(name="Enabled", value=str(enabled), inline=True)
+        embed.add_field(name="Chat Channel", value=channel_str, inline=True)
+        embed.add_field(name="API Key", value="Set" if has_key else "Not set", inline=True)
+        embed.add_field(name="Model", value=model, inline=True)
+        embed.add_field(name="Temperature", value=str(temp), inline=True)
+        embed.add_field(name="Question Mode", value=str(q_mode), inline=True)
+        embed.add_field(name="System Prompt", value=sys_prompt[:200], inline=False)
+
+        await ctx.send(embed=embed)
diff --git a/greeptchat/info.json b/greeptchat/info.json
new file mode 100644
index 0000000..78f67da
--- /dev/null
+++ b/greeptchat/info.json
@@ -0,0 +1,11 @@
+{
+    "author": ["Scrapyard Cogworks"],
+    "install_msg": "GreeptChat cog installed. Use [p]greept to configure.",
+    "name": "GreeptChat",
+    "short": "AI chat via GreenPT API with channel and ping modes.",
+    "description": "Connects to the GreenPT OpenAI-compatible API for AI chat. Set a dedicated chat channel or get responses when the bot is pinged. Supports temperature, model, system prompt, and question mode.",
+    "tags": ["ai", "chat", "greenpt", "gpt", "llm"],
+    "requirements": ["aiohttp"],
+    "min_bot_version": "3.5.0",
+    "end_user_data_statement": "This cog stores conversation history per channel in memory only."
+}