initial commit, moved libpanto over from the pantograph repo

1 files changed, 103 insertions, 0 deletions

diff --git a/examples/simple-agent.lua b/examples/simple-agent.lua
new file mode 100644
index 0000000..baf00b5
--- /dev/null
+++ b/examples/simple-agent.lua
@@ -0,0 +1,103 @@
+#!/usr/bin/env lua
+-- A tiny standalone libpanto-lua app: one prompt in, streamed text out.
+--
+-- Run with Lua 5.4 after building/installing libpanto-lua, for example:
+--   LUA_CPATH='./libpanto-lua/zig-out/lib/?.so;;' lua examples/simple-agent.lua "list the files"
+--
+-- Required environment:
+--   PANTO_API_STYLE=openai_chat|anthropic_messages
+--   PANTO_API_KEY=...
+--   PANTO_BASE_URL=...
+--   PANTO_MODEL=...
+
+local panto = require("panto")
+
+local function getenv(name, default)
+    local value = os.getenv(name)
+    if value == nil or value == "" then return default end
+    return value
+end
+
+local function require_env(name)
+    local value = getenv(name)
+    if value == nil then error("missing required env var: " .. name, 0) end
+    return value
+end
+
+local function shell_quote(s)
+    return "'" .. tostring(s):gsub("'", "'\\''") .. "'"
+end
+
+local function read_all(pipe)
+    local chunks = {}
+    while true do
+        local chunk = pipe:read(8192)
+        if chunk == nil then break end
+        chunks[#chunks + 1] = chunk
+    end
+    return table.concat(chunks)
+end
+
+local function run_bash(command)
+    local wrapped = "bash -lc " .. shell_quote(command) .. " 2>&1; printf '\\n__panto_exit_code:%s\\n' $?"
+    local pipe = assert(io.popen(wrapped, "r"))
+    local output = read_all(pipe)
+    pipe:close()
+
+    local body, code = output:match("^(.*)\n__panto_exit_code:(%-?%d+)\n$")
+    return string.format("exit_code=%s\n%s", code or "unknown", body or output)
+end
+
+local prompt = table.concat(arg, " ")
+if prompt == "" then
+    io.stderr:write("usage: lua examples/simple-agent.lua <prompt>\n")
+    os.exit(2)
+end
+
+local agent = panto.agent {
+    api_style = require_env("PANTO_API_STYLE"),
+    api_key = require_env("PANTO_API_KEY"),
+    base_url = require_env("PANTO_BASE_URL"),
+    model = require_env("PANTO_MODEL"),
+    max_tokens = tonumber(getenv("PANTO_MAX_TOKENS", "4096")),
+}
+
+agent:set_system_prompt(table.concat({
+    "You are a very small coding agent.",
+    "Use the bash tool when you need to inspect or change the local workspace.",
+    "Keep final answers concise.",
+}, "\n"))
+
+agent:register_tool {
+    name = "bash",
+    description = "Run a shell command with bash -lc and return combined stdout/stderr plus the exit code.",
+    schema = {
+        type = "object",
+        properties = {
+            command = {
+                type = "string",
+                description = "The command to run.",
+            },
+        },
+        required = { "command" },
+    },
+    handler = function(input)
+        if type(input.command) ~= "string" or input.command == "" then
+            error("bash.command must be a non-empty string")
+        end
+        return run_bash(input.command)
+    end,
+}
+
+for ev in agent:run(prompt):events() do
+    if ev.type == "content_delta" then
+        io.write(ev.delta)
+        io.flush()
+    elseif ev.type == "tool_dispatch_start" then
+        io.stderr:write(string.format("\n[bash: running %d tool call(s)]\n", ev.count))
+    elseif ev.type == "tool_dispatch_complete" then
+        io.stderr:write("[bash: done]\n")
+    end
+end
+
+io.write("\n")