Claude Code with Opus 4.6 regularly uses sed for multi-line edits, in my experience. On top of it, Pi is famously only exposing 4 tools, which is not just Bash, but far more constrained than CCs 57 or so tools.

So, yes, it can work.

I think the problem/limitation would be as much due to context management as tools. Obviously bash plus a few utilities is sufficient to explore/edit the code base, but I can't imagine this working reliably without the models being specifically trained to use specific tools, and recognize/adapt to different versions of them etc.

Context management, both within and across sessions, seems the bigger issue. Without the agent supporting this, you are at the mercy of the model compacting/purging the context as needed, in some generic fashion, as well as being smart enough to decide to create notes for itself tracking what it is doing, etc.

Apparently CC is 512K LOC, which seems massively bloated, but I do think that things like tools, skills, context management and subagents are all needed to effectively manage context and avoid the issues that might be anticipated by just telling the model it's got a bash tool, and go figure.

I thought CC only supports it's find/replace edit tool (implemented by CC itself, using Node.js for file access), and is platform agnostic. Are you saying that on linux CC offers "sed" as a tool too? I can't imagine it offers "bash" since that's way too dangerous.