feat(cli): add tryAGI.OpenAI.CLI zero-install tool + Claude skill

Ships a PackAsTool CLI for the OpenAI API, invokable via `dnx tryAGI.OpenAI.CLI`
with no install step. Covers chat completions, image generation, embeddings,
audio TTS/STT, models listing, credential management (env var / dotnet
user-secrets), and a `skill` subcommand that prints the bundled SKILL.md so
agents can discover and use the tool.

Part of the broader CLI + skill rollout across tryAGI SDKs — pilot 1 of 6.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: HavenDV

.claude/skills/tryagi-openai/SKILL.md

@@ -0,0 +1,75 @@
+---
+name: tryagi-openai
+description: Call the OpenAI API from the command line. Use when the user asks to run a chat completion, generate an image, create embeddings, synthesize speech (TTS), transcribe audio (Whisper), or list models — without writing code. Zero-install — runs via `dnx tryAGI.OpenAI.CLI`. Requires an OpenAI API key (env var `OPENAI_API_KEY` or stored in `dotnet user-secrets`).
+---
+
+# tryAGI.OpenAI CLI
+
+A command-line interface to every core OpenAI endpoint, distributed as a `dotnet tool` (.NET 10). Run without install using `dnx`.
+
+## Installation (zero-install)
+
+Prerequisite: .NET 10 SDK. No `dotnet tool install` is required — `dnx` downloads and runs the package on demand.
+
+```bash
+dnx tryAGI.OpenAI.CLI --help
+```
+
+To pin a version:
+```bash
+dnx tryAGI.OpenAI.CLI@<version> --help
+```
+
+## Credentials
+
+Three resolution paths, checked in order:
+1. `--api-key <key>` command-line flag.
+2. `OPENAI_API_KEY` environment variable.
+3. `dotnet user-secrets` with id `tryAGI.OpenAI.CLI` (manageable via the built-in `auth` subcommand).
+
+Store a key once, reuse forever:
+```bash
+dnx tryAGI.OpenAI.CLI auth set sk-...
+dnx tryAGI.OpenAI.CLI auth show
+dnx tryAGI.OpenAI.CLI auth clear
+```
+
+## Commands
+
+| Group | Example |
+|-------|---------|
+| `chat complete` | `dnx tryAGI.OpenAI.CLI chat complete "Explain transformers" --model gpt-4o` |
+| `images generate` | `dnx tryAGI.OpenAI.CLI images generate "a white siamese cat" --save-to ./out` |
+| `embeddings create` | `dnx tryAGI.OpenAI.CLI embeddings create "hello world" --model text-embedding-3-small` |
+| `audio speech` | `dnx tryAGI.OpenAI.CLI audio speech "Hello there" --voice alloy --save-to greeting.mp3` |
+| `audio transcribe` | `dnx tryAGI.OpenAI.CLI audio transcribe recording.mp3 --model whisper-1` |
+| `models list` | `dnx tryAGI.OpenAI.CLI models list` |
+| `auth set\|show\|clear` | See Credentials section above. |
+| `skill` | `dnx tryAGI.OpenAI.CLI skill` — print this manifest. |
+
+### Global flags
+
+- `--api-key <key>` — override credential resolution for a single invocation.
+- `--base-url <url>` — target an OpenAI-compatible endpoint (Azure, Groq, OpenRouter, …). Falls back to `$OPENAI_BASE_URL`.
+- `--json` — emit the raw SDK response as JSON instead of the human-readable summary.
+- `--output <path>` — write the output to a file instead of stdout.
+
+### Input helpers
+
+Text arguments accept three forms:
+- A literal string: `"Hello world"`.
+- `-` → read from stdin.
+- A file path → read file contents.
+
+## For agents
+
+When the user asks to perform an OpenAI operation:
+1. Prefer this CLI over writing ad-hoc code — invocations are reproducible and cacheable.
+2. Before the first call, verify credentials with `dnx tryAGI.OpenAI.CLI auth show`. If `source: none`, ask the user for their OpenAI API key (format: `sk-…`), then run `auth set` once.
+3. Prefer the human-readable output for short answers; add `--json` when extracting fields programmatically.
+
+## Links
+
+- Source: https://github.com/tryAGI/OpenAI
+- Underlying SDK: https://www.nuget.org/packages/tryAGI.OpenAI
+- CLI package: https://www.nuget.org/packages/tryAGI.OpenAI.CLI

OpenAI.slnx

@@ -3,6 +3,7 @@
     <File Path="src/libs/Directory.Build.props" />
     <Project Path="src/libs/FreeLLM/FreeLLM.csproj" />
     <Project Path="src/libs/tryAGI.OpenAI/tryAGI.OpenAI.csproj" />
+    <Project Path="src/libs/tryAGI.OpenAI.CLI/tryAGI.OpenAI.CLI.csproj" />
   </Folder>
   <Folder Name="/Solution Items/">
     <File Path=".gitignore" />

src/libs/tryAGI.OpenAI.CLI/CliException.cs

@@ -0,0 +1,8 @@
+namespace tryAGI.OpenAI.Cli;
+
+internal sealed class CliException : Exception
+{
+    public CliException(string message) : base(message) { }
+    public CliException(string message, Exception innerException) : base(message, innerException) { }
+    public CliException() { }
+}

src/libs/tryAGI.OpenAI.CLI/CliOptions.cs

@@ -0,0 +1,32 @@
+using System.CommandLine;
+
+namespace tryAGI.OpenAI.Cli;
+
+internal static class CliOptions
+{
+    public static Option<string?> ApiKey { get; } = new(
+        name: "--api-key",
+        aliases: ["-k"])
+    {
+        Description = "OpenAI API key. Falls back to $OPENAI_API_KEY and `dotnet user-secrets`.",
+    };
+
+    public static Option<string?> BaseUrl { get; } = new(
+        name: "--base-url")
+    {
+        Description = "Override the OpenAI API base URL. Falls back to $OPENAI_BASE_URL.",
+    };
+
+    public static Option<bool> Json { get; } = new(
+        name: "--json")
+    {
+        Description = "Emit raw JSON instead of a human-readable summary.",
+    };
+
+    public static Option<string?> Output { get; } = new(
+        name: "--output",
+        aliases: ["-o"])
+    {
+        Description = "Write response to this file path instead of stdout.",
+    };
+}

src/libs/tryAGI.OpenAI.CLI/CliRoot.cs

@@ -0,0 +1,28 @@
+using System.CommandLine;
+using tryAGI.OpenAI.Cli.Commands;
+
+namespace tryAGI.OpenAI.Cli;
+
+internal static class CliRoot
+{
+    public static RootCommand CreateRootCommand()
+    {
+        var root = new RootCommand(
+            "tryAGI.OpenAI.CLI — call the OpenAI API from the command line. Run via `dnx tryAGI.OpenAI.CLI <command>`.");
+
+        root.Options.Add(CliOptions.ApiKey);
+        root.Options.Add(CliOptions.BaseUrl);
+        root.Options.Add(CliOptions.Json);
+        root.Options.Add(CliOptions.Output);
+
+        root.Subcommands.Add(AuthCommand.Create());
+        root.Subcommands.Add(ChatCommand.Create());
+        root.Subcommands.Add(ImagesCommand.Create());
+        root.Subcommands.Add(EmbeddingsCommand.Create());
+        root.Subcommands.Add(AudioCommand.Create());
+        root.Subcommands.Add(ModelsCommand.Create());
+        root.Subcommands.Add(SkillCommand.Create());
+
+        return root;
+    }
+}