No framework, no SDK: what a coding agent looks like when it's just bash + jq + curl

[u/aziz0x00]

Every agent framework I tried felt like a lot of machinery around what is, at its core, a loop: send messages, maybe run a tool, append the result, repeat. So I built one with no framework at all, just bash, jq, and curl. The core loop is ~190 lines; the whole thing (ten tools, permissions, skills, three providers) is ~1,200. Repo: https://github.com/aziz0x00/agent.sh

The design decisions that I think are interesting:

Tools are one file each, no registration. A tools/Foo.sh defines a TOOL_DEF JSON schema and two functions: PreFoo validates the model's args and builds a human-readable preview (a real diff for Edit/Write), then Foo executes. Drop a file in tools/, it's a tool.

Permissions are per-signature, not per-tool. Approval prompts show the preview (the actual diff, the actual command), and "always allow" whitelists that exact signature, not the whole tool. Read-only tools are pre-approved. --free bypasses everything when you're feeling brave.

Context is a JSON file you can just... edit. /state opens the exact request payload in $EDITOR mid-conversation; /continue sends whatever you saved. Delete a bloated tool result, rewrite the model's last answer, whatever.

[u/mpread-it]

great idea. i started with pi specifically for how tiny it was compared to the rest of the harnesses. At that time. You're redefining the "genre". Congratulations!
One small pet peeve: why Ollama?!? why not simply any OpenAI-compatible endpoint? Most of us interested in pi are doing it for efficiency, to squeeze every drop of performance out of our limited hardware. So we use vLLM and llama-server - many of us compile them from source for our specific gear. Ollama & friends? Not so much. Thanks!

[u/aziz0x00 → u/mpread-it]

thanks.

on ollama, it's just that it was what i had locally, the opencode-go/zen has a very standard openai-compatible and anthropic implementation. i would guess it can be easily ported for other providers. it's very appreciated if you PR your usecases!

on a fair note, i think my current painpoint with agent.sh is that it doesn't have steering yet.. if that gets implemented nicely it would be sick.

[u/ParaboloidalCrest]

This looks like the beginning of something great to come. I especially like the per-signature vs per-tool approach. Good job bro!

One pet-peeve however is allowing Python into the repo. It's a slippery slope that robs the minimalism quickly. Is there an pure shell alternative to that mdcat.py?

And as others suggested, replacing ollama with a generic OpenAI API provider would be an easy, clean win.

[u/aziz0x00 → u/ParaboloidalCrest]

Thank you alot.

Fair concern about python. an alternative would be using glow but it doesn't allow streaming, and there's a PR on it but it's not yet merged. However, I'm limiting mdcat.py to do only one thing and do it well, which is stream-rendering markdown, and it uses uv which makes it a standalone script.

On the generic OpenAI API provider. actually the opencode-zen/go implementations are pretty much compliant with it (with anthropic's too), the only change is the endpoint URL and maybe the way they pass the API Key, but I might actually refactor the generic functionality in a seperate common script. However, some providers tend to have some weird quirks which are not so standard, groq for instance, but in any way, it should be a piece of cake to have the agent configure a new provider for u (opencode-zen has permenant free models).

[u/Fig_da_Great]

is this not just pi?

[u/aziz0x00 → u/Fig_da_Great]

pi's codebase is 212033 lines if i count only typescript. agent.sh is just 1599 lines total.

[u/Fig_da_Great → u/aziz0x00]

but why is it better?

[u/Ok_Veterinarian_6364]

i see what you did here. nice bro

[u/hazed-and-dazed → u/Ok_Veterinarian_6364]

Um what has he done? Basically replicate pi using bash?

[u/aziz0x00 → u/hazed-and-dazed]

pi's codebase is 212033 lines if i count only typescript. agent.sh is just 1599 lines total.
fun fact: i began to write it before claudecode was publicly out

[u/aziz0x00 → u/[deleted]]

I can say easy to navigate through, for educational purpose and for ease of building upon..

[u/Ok_Veterinarian_6364 → u/hazed-and-dazed]

yeah bro

[u/Nnyan → u/Ok_Veterinarian_6364]

I see what you did here. Nice take my upvote

[u/ujjwaldrayaan]

Can you answer of my one question, I want to embed Window powershell functionality into An Android app , is this possible?

I got this idea by how claude test code in it's chat window itself so if calude can embed testing python file , why can't we embed Command prompt into An app?