# What this is

A tiny Bash client for OpenAI's Chat Completions API. You give it a prompt (via args, a file, or stdin), it calls the API with a chosen model, prints the assistant's reply to stdout, and prints token usage to stderr. It can also stream tokens as they arrive, still reporting usage at the end.

## Key behavior, step by step

1.	Safety & env
	-	set -euo pipefail → exit on errors, unset vars, or failed pipes.
	-	Requires curl and jq.
	-	Requires OPENAI_API_KEY in the environment; exits if missing.

2.	Arguments
	-	-model <name>: pick the model (default gpt-4o-mini).
	-	--list-models: list available models (via GET /v1/models) and exit.
	-	-prepend <text>: prefix text added before the main prompt (with a blank line separation).
	-	-content-from-file <file>: read the prompt from a file.
	-	--stream: stream the response tokens (Server-Sent Events).
	-	Prompt text can also be passed as plain arguments, or piped via stdin if no args/file.

3.	Prompt building
	-	Collects the main content from (priority):

4.	-content-from-file, else 2) remaining command-line words, else 3) stdin (if piped).
	-	If -prepend is set, it's added above the main content with two newlines.
	-	The combined text is JSON-escaped via jq -Rs . and used as the user message.

5.	Non‑streaming mode (default)
	-	POSTs to https://api.openai.com/v1/chat/completions with:```{ "model": "...", "messages": [{"role": "user", "content": "..."}] } ```
	-	Prints the assistant's reply (.choices[0].message.content) to stdout.
	-	If present, prints token usage (prompt/completion/total) to stderr as: ```tokens: prompt=... completion=... total=...```

6.	Streaming mode (--stream)
	-	Sends the same request but with "stream": true and```"stream_options": {"include_usage": true} so the final SSE chunk contains usage.```
	-	Reads data: lines from the SSE stream:
	-	Prints incremental content chunks (.choices[0].delta.content) to stdout as they arrive (no newline until done).
	-	When a chunk contains a .usage object, it prints a newline to stdout, then the usage line to stderr.
	-	Ensures output ends with a newline even if usage wasn't received for some reason.

7.	Exit & errors
	-	Clear error messages for missing deps, missing key, missing file, or empty prompt.
	-	Returns non‑zero on those errors due to set -e.
---
## Usage examples:
#### Simple call:
```bash
OPENAI_API_KEY=... ./askChatGPT.sh "Explain WebSockets to a 10-year-old"
```

#### With prepend (e.g., a system-ish instruction):
```bash
./askChatGPT.sh -prepend "You are concise." "Summarize Bitcoin halvings."
```

#### From file:
```bash
./askChatGPT.sh -content-from-file prompt.txt
```

#### From stdin:
```bash
echo "Translate this to Finnish:" | ./askChatGPT.sh
```

#### Streaming (prints tokens live, usage at end):
```bash
./askChatGPT.sh --stream "Write a limerick about Helsinki"
```

#### List models:
```bash
./askChatGPT.sh --list-models
```


## Notes & gotchas
-	API family: It uses the /v1/chat/completions endpoint. That's fine, but OpenAI also has a newer Responses API; feature parity and latencies may differ.
-	Usage-to-stderr: Handy for logging—e.g., you can capture text with >reply.txt while keeping usage separate.
-	Model names: Ensure gpt-4o-mini is available to your account; otherwise use --list-models to check and pass -model ....
-	SSE parsing: The script filters lines starting with data: and stops at [DONE]. It's tolerant of lines without content.

If you want, I can add a -system flag to let you send a separate system message, or add support for temperature / max_tokens.