[nr378]

Nice work.

It strikes me there's more low hanging fruit to pluck re. context window management. Backtracking strikes me as another promising direction to avoid context bloat and compaction (i.e. when a model takes a few attempts to do the right thing, once it's done the right thing, prune the failed attempts out of the context).

[elephanlemon]

Agree. I’d like more fine grained control of context and compaction. If you spend time debugging in the middle of a session, once you’ve fixed the bugs you ought to be able to remove everything related to fixing them out of context and continue as you had before you encountered them. (Right now depending on your IDE this can be quite annoying to do manually. And I’m not aware of any that allow you to snip it out if you’ve worked with the agent on other tasks afterwards.)

I think agents should manage their own context too. For example, if you’re working with a tool that dumps a lot of logged information into context, those logs should get pruned out after one or two more prompts.

Context should be thought of something that can be freely manipulated, rather than a stack that can only have things appended or removed from the end.

[FuckButtons]

Yeah, the fact that we have treated context as immutable baffles me, it’s not like humans working memory keeps a perfect history of everything they’ve done over the last hour, it shouldn’t be that complicated to train a secondary model that just runs online compaction, eg: it runs a tool call, the model determines what’s Germaine to the conversion and prunes the rest, or some task gets completed, ok just leave a stub in the context that says completed x, with a tool available to see the details of x if it becomes relevant again.

[mksglu]

That's pretty much the approach we took with context-mode. Tool outputs get processed in a sandbox, only a stub summary comes back into context, and the full details stay in a searchable FTS5 index the model can query on demand. Not trained into the model itself, but gets you most of the way there as a plugin today.

[FuckButtons]

This is a partial realization of the idea, but, for a long running agent the proportion of noise increases linearly with the session length, unless you take an appropriately large machete to the problem you’re still going to wind up with sub optimal results.

[jerf]

Yeah, I'd definitely like to be able to edit my context a lot more. And once you consider that you start seeing things in your head like "select this big chunk of context and ask the model to simply that part", or do things like fix the model trying to ingest too many tokens because it dumped a whole file in that it didn't realize was going to be as large as it was. There's about a half-dozen things like that that are immediately obviously useful.

[esperent]

Is it because of caching? If the context changes arbitrarily every turn then you would have to throw away the cache.

[FuckButtons]

So use a block based cache and tune the block size to maximize the hit rate? This isn’t rocket science.

[wonnage]

This seems misguided, you have to cache a prefix due to attention.

[nr378]

Oh that's quite a nice idea - agentic context management (riffing on agentic memory management).

There's some challenges around the LLM having enough output tokens to easily specify what it wants its next input tokens to be, but "snips" should be able to be expressed concisely (i.e. the next input should include everything sent previously except the chunk that starts XXX and ends YYY). The upside is tighter context, the downside is it'll bust the prompt cache (perhaps the optimal trade-off is to batch the snips).

[lowbloodsugar]

So I built that in my chat harness. I just gave the agent a “prune” tool and it can remove shit it doesn’t need any more from its own context. But chat is last gen.

[mksglu]

Good point on prompt cache invalidation. Context-mode sidesteps this by never letting the bloat in to begin with, rather than snipping it out after. Tool output runs in a sandbox, a short summary enters context, and the raw data sits in a local search index. No cache busting because the big payload never hits the conversation history in the first place.

[MichaelDickens]

> I think agents should manage their own context too.

My intuition is that this should be almost trivial. If I copy/paste your long coding session into an LLM and ask it which parts can be removed from context without losing much, I'm confident that it will know to remove the debugging bits.

[bbatha]

I generally do this when I arrive at the agent getting stuck at a test loop or whatever after injecting some later requirement in and tweaking. Once I hit a decent place I have the agent summarize, discard the branch (it’s part of the context too!) and start with the new prompt

[esperent]

> For example, if you’re working with a tool that dumps a lot of logged information into context

I've set up a hook that blocks directly running certain common tools and instead tells Claude to pipe the output to a temporary file and search that for relevant info. There's still some noise where it tries to run the tool once, gets blocked, then runs it the right way. But it's better than before.

[wonnage]

I think telling it to run those in a subagent should accomplish the same thing and ensure only the answer makes it to the main context. Otherwise you will still have some bloat from reading the exact output, although in some cases that could be good if you’re debugging or something

[esperent]

Not really because it reliably greps or searches the file for relevant info. So far I haven't seen it ever load the whole file. It might be more efficient for the main thread to have a subagent do it but probably at a significant slowdown penalty when all I'm doing is linting or running tests. So this is probably a judgement call depending on the situation.

[mullingitover]

I’ve been wondering about this and just found this paper[1]: Agentic Context Engineering: Evolving Contexts for Self-Improving Language Models

Looks interesting.

[1] https://arxiv.org/html/2510.04618v1

[mksglu]

That's exactly what context-mode does for tool outputs. Instead of dumping raw logs and snapshots into context, it runs them in a sandbox and only returns a summary. The full data stays in a local FTS5 index so you can search it later when you need specifics.

[8note]

what i want is for the agent to initially get the full data and make the right decision based on it, then later it doesnt need to know as much about how it got there.

isnt that how thinking works? intermediate tokens that then get replaced with the reuslt?

[dsclough]

Trees in pi let you do this, after done debugging you move back up and continue, leaving all the debugging context in its own branch

[8note]

i think something kinda easy for that could be to pretend that pruned output was actually done by a subagent. copy the detailed logs out, and replace it with a compacted summary.

[jaredsohn]

Treat context like git shas. Yes, there is a specific order within a 'branch' but you should be able to do the equivalent of cherry-picking and rebasing it

[IncreasePosts]

I do this with my agents. Basically, every "work" oriented call spawns a subprocess which does not add anything to the parent context window. When the subprocess completes the task, I ask it to 1) provide a complete answer, 2) provide a succinct explanation of how the answer was arrived at, 3) provide a succinct explanation of any attempts which did not work, and 4) Anything learned during the process which may be useful in the future. Then, I feed those 4 answers back to the parent as if they were magically arrived at. Another thing I do for managing context window is, any tool/MCP call has its output piped into a file. The LLM then can only read parts of the file and only add that to its context if it is sufficient. For example, execute some command that produces a lot of output and ultimately ends in "Success!", the LLM can just tail the last line to see if it succeeded. If it did, the rest of the output doesn't need to be read. if it fails, usually the failure message is at the end of the log. Something I'm working on now is having a smaller local model summarize the log output and feed that summarization to the more powerful LLM (because I can run my local model for ~free, but it is no where near as capable as the cloud models). I don't keep up with SOTA so I have no idea if what I'm doing is well known or not, but it works for me and my set up.

[jonnycoder]

It feels like the late 1990s all over again, but instead of html and sql, it’s coding agents. This time around, a lot of us are well experienced at software engineering and so we can find optimizations simply by using claude code all day long. We get an idea, we work with ai to help create a detailed design and then let it develop it for us.

[mksglu]

The people who spent years doing the work manually are the ones who immediately see where the bottlenecks are.

[mksglu]

Totally agree. Failed attempts are just noise once the right path is found. Auto-detecting retry patterns and pruning them down to the final working version feels very doable, especially for clear cases like lint or compilation fixes.

[ip26]

Maybe the right answer is “why not both”, but subagents can also be used for that problem. That is, when something isn’t going as expected, fork a subagent to solve the problem and return with the answer.

It’s interesting to imagine a single model deciding to wipe its own memory though, and roll back in time to a past version of itself (only, with the answer to a vexing problem)

[jon-wood]

I forget where now but I'm sure I read an article from one of the coding harness companies talking about how they'd done just that. Effectively it could pass a note to its past self saying "Path X doesn't work", and otherwise reset the context to any previous point.

I could see this working like some sort of undo tree, with multiple branches you can jump back and forth between.