Claude Code sends 33k tokens before reading the prompt; OpenCode sends 7k
169 points by systima 2 hours ago | 98 comments
This started based off of a hunch. We usually use OpenCode, but were 'forced' to use Claude Code for a while due to issues with Meridian. In that time, we saw the usage meter rise much, much more quickly than when using OpenCode.

This was the initial anecdotal evidence, but we undertook this small study to collect empirical data:

We added logging between the agentic coding tool (Claude Code and OpenCode) and Anthropic's endpoint, and captured all requests (and the returned usage blocks).

With one caveat (toward the end of the post) we found unambiguously that Claude Code was far more inefficient in terms of its cache strategy and its harness token usage than OpenCode.


mcv 36 minutes ago
What really burns tokens is sub agents. I once gave Claude Code a pretty big task, and it immediately launched 7 sub agents which burned through my budget before even one of them was finished. Tried again 5 hours later: same result.

If I let the main agent do the same task sequentially, it was no problem at all. I don't know if it's really just communication and orchestration that makes sub agents so inefficient, or if Anthropic figured that most people using sub agents pay per token on a big corporate account, so this is an easy way to make more money from tokenmaxxers.

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ValentineC 3 minutes ago
> What really burns tokens is sub agents. I once gave Claude Code a pretty big task, and it immediately launched 7 sub agents which burned through my budget before even one of them was finished. Tried again 5 hours later: same result.

Probably because the general purpose subagents inherit the parent model.

I tell Claude explicitly to use Explore subagents, which use Haiku only, now.

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btown 21 minutes ago
As a counterpoint: in a complex project, Fable's "curiosity" may be exactly what you want for an exploration and planning stage - not just for the orchestrator that turns your prompt into different angles with which to explore, but for each subagent whose task is to search the codebase for one of those "angles." If you truly want no stone unturned, letting those subagents spawn their own discoveries, and recursively grow the surface area of the inquiry, then it's quite reasonable to want Fable throughout.

That said, if your project is "do this well-planned thing on a bunch of things in parallel" then you should absolutely be instructing to have subagents "step down" to less curious models. Their output may well be more cohesive as a result!

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wongarsu 10 minutes ago
Sub agents each have to read part of your code base again to get enough context for the task. And if they take too long, your orchestrator's context is no longer in cache so you pay full price for that again once the subagents finish

If you do it sequentially you only read those files approximately once, and everything hits the same prefix cache

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a_c 24 minutes ago
Every subagent send the same ~30k system prompts. If you are using fable/opus, that's easily 30% of a 5-hour window for 7 subagent, before doing any work
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micw 18 minutes ago
I recently did a few tests. And always the same prompt has been cached properly.
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megous 17 minutes ago
If it's always the same prompt, can't they have it pre-cached globally for all?
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erikus 8 minutes ago
I'm pretty sure the system instructions are a function of your environment and not the same universally. That said, there should be a finite number of branches so still cacheable.
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qpricjalcbeu 28 minutes ago
And in my experience the sub agent performance is usually worse than just a single agent.
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tudelo 24 minutes ago
I find it useful for code reviews (spawn a subagent with minimal/no context to review X commit). Of course, this is more or less a shortcut that could be done with a seperate agent. Another use is multiple reviews at once if tokens are not an issue, with seperate "personas" or focuses. As far as implementation goes I have not seen any major usecase.
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thejazzman 31 minutes ago
for subagents to be cheap/effective, you have to specify the size of those subagents; i.e. right now by default 5.6-sol spawns many 5.6-sol subagents. 5.4-mini as subagent saves me tons of tokens. 5.6-sol audits the work before accepting it, so there's not really a quality issue.
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retired 26 minutes ago
Did it deploy five AWS m8g.12xlarge instances?
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korrectional 51 minutes ago
My opinion is that claude code uses more tokens simply because Anthropic makes more money that way and forces people into their subscriptions. This is supported by the fact that they won't let you use your sub on a different coding agent. I use pi btw.
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claw-el 12 minutes ago
Once I realized that Anthropic is a token merchant, I start to understand Anthropic’s decision more. They are always finding reasons for you to use more tokens through them unless the users revolt or demand some guardrails.
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paxys 35 minutes ago
You're making the opposite argument. Anthropic is incentivized to use less tokens in Claude Code because people are paying a fixed monthly fee for subscriptions.
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FuckButtons 34 minutes ago
Nope, that’s not true, because they want you to pay for the higher subscription bracket.
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tjoff 6 minutes ago
Well since what you get for your subscription is unknown it would be trivial to get that result without burning tokens.

Especially since compute is such a scarce resource.

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jchook 30 minutes ago
Can confirm — they got me paying $100/mo this way.

Also I think it’s well known that OpenAI is the much less expensive option (in tokens and $$). For the same $20 you get a lot more mileage.

Curious if folks have strong opinions about the overall UX of OpenCode vs CC…

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erikus 5 minutes ago
For me as well, at least this month to use more of Fable. We'll see if they extend Fable access because of people like me.
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bpodgursky 16 minutes ago
If they wanted to play games with sub tiers they would just change the rate limits rather than wasting inference.
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VulgarExigency 25 minutes ago
Enterprise users are not paying a fixed fee, though
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whazor 9 minutes ago
Yeah, I strongly recommend against Claude Enterprise, it is ridiculously expensive and hard to control costs.
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toddmorey 43 minutes ago
I thought I read somewhere that according to filings for going public, subscription revenue is tiny… like 5%.

Edit: consumer Claude subs are the 5%. I’d bet most all of CC subs lump in under enterprise.

  - API & Enterprise: 75% to 85% of total revenue.
  - Business Subscriptions: Roughly 10% to 15%.
  - Individual Subscriptions: About 5%.
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Quot 35 minutes ago
The vast majority of my company's enterprise plan use is through Claude Code even though we have access to the API and could be using OpenCode instead.

I don't fully agree with the premise that they intentionally increase system prompts, but the enterprise plan usage is going to make that a huge income for Anthropic.

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hobofan 21 minutes ago
> I use pi btw

Not sure if intentionally meant as a reference, but it gives "I use Arch btw" vibes.

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lanthissa 28 minutes ago
the amount of system prompt wastage going on in orgs is insane. we identified 400k in annual burn for zero value in just one section of our large company.

and the interesting thing about system prompt wastage is its a cost that scales non linearly with subagent use.

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hvb2 39 minutes ago
> This is supported by the fact that they won't let you use your sub on a different coding agent

I mean, that's a very weak argument? Isn't a much more plausible explanation that with your tooling you'll have more of a lock-in than with just your model?

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systima 19 minutes ago
UPDATE:

After reading PUSH_AX's valid comment: ``` This is like saying contractor (A) asked for $33,000 to undertake the work and contractor (B) asked for $7,000 Are we measuring and caring about the right thing? ``` We will update the post to include:

1) A more in-depth task. 2) Qualitative results comparison. 3) As soon as possible, a reproduction of the inputs and outputs.

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Schiendelman 3 minutes ago
Thanks, I'm looking forward to this!

I wonder if a lot of the 33k is context, like from recent conversations.

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estetlinus 39 minutes ago
Recently switched to Codex after 6m in Claude. Codex seems more open, it’s easier to follow what the model is doing and the approvals have a better UX. Overall, it just feels more transparent. Cost of switching was close to 0.

I don’t like that Claude became more opaque around February, including the system prompts. 33k feels way too much.

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Schiendelman 4 minutes ago
What settings have you tried since it "became more opaque"? They've got a lot more settings now.
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syntaxing 9 minutes ago
The reasoning built into the models matter so much too. I recently swapped my Qwen3.6 27B to ThinkingLabs’ fine tune and it does what it publishes. I cut my token usage in half, which is a big deal since I only get ~20 TPS for token generation.
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jakozaur 2 hours ago
This isn’t limited to large system prompts. Coding-agent harnesses are also becoming more aggressive about using tools, even for trivial requests. In our tests, prompts such as “Hey” or “commit” sometimes triggered 30+ tool calls:

https://quesma.com/blog/the-true-cost-of-saying-hi-to-an-ai-...

Tokenflation seems very real: the number of tokens consumed by simple tasks keeps increasing.

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prymitive 56 minutes ago
I often find myself annoyed when Opus fixes a typo in a comment and decides to run tests, lints and whenever else it can find to run. Often it will start by stashing current changes just to preemptively check if all tests were passing before. And I can blame myself a bit because my rules do say: verify all changes with tests. But as there is that I in AI that is hyped which you’d think means it knows not to put tomatoes into fruit salad …
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mh- 44 minutes ago
> [..] my rules do say: verify all changes with tests

I am a bit surprised that you're disappointed that it does exactly what you told it to - people usually have the opposite complaint.

If you're using it interactively and watching what it changes, I'd trigger the tests when you think it's needed. And if you want to go more hands-off, why not add try to encode the same nuance you'd use into the rule?

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redox99 43 minutes ago
Following rules like "verify all changes with tests" down to a tee is usually a desirable trait in LLMs. Personally I'd leave that behavior there (just like with humans for some tasks like aviation you have them go through checklists even if some stuff you can infer is not needed). But otherwise just make it "always run tests unless you're absolutely sure they can be skipped".
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dymk 25 minutes ago
Add "... unless the changes are trivial, docs-only, or typo fixes" to the "always verify with tests" instruction and see how that does
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Chris2048 31 minutes ago
> prompts such as “Hey” or “commit” sometimes triggered 30+ tool calls

I read that this is because it wastes time looking through past conversations and other context to figure one what you might want it to do - a less ambiguous prompt would be better.

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alex7o 59 minutes ago
I am forced to use cloude code at work but a good solution is to just use --system-prompt "" and be done with it. I wish they allowed for other harnesses.
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venusenvy47 11 minutes ago
Do you start Claude with this option? Or do you send this with every prompt?
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cube00 36 minutes ago
> --system-prompt ""

Doesn't the model need at least a basic system prompt to understand what tools are available?

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lanyard-textile 50 seconds ago
The flag name is overloaded. It won't affect the tools available, just the other system instructions.
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AndyNemmity 29 minutes ago
Yep, have been using this for a long time now. No idea why everyone doesn’t.
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tyleo 55 minutes ago
I didn’t know you could do this. Is there any analysis of the impact, before and after? I’d love to see some charts of efficacy in real world usage.
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alex7o 44 minutes ago
It shows up in /context, but never spend time validating it much. Some people run a proxy to modify their messages.
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mft_ 2 hours ago
Early on in experimenting with local models, I found that hooking them up to Claude Code worked very well, but it was also really slow.

I used mitmproxy (setup assisted by Claude, natch) to capture Claude Code's entire initial system prompt and the whole thing was (I just double-checked) 162k of JSON.

This led me to start experimenting with Pi, OpenCode, and Hermes...

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mh- 38 minutes ago
This is interesting, because if I start a fresh session of Claude Code right now and run /context, I see the following:

   Opus 4.8 (1M context)
   claude-opus-4-8[1m]
   23k/1m tokens (2%) 

   Estimated usage by category
   System prompt: 3.9k tokens (0.4%)
   System tools: 13.9k tokens (1.4%)
   Custom agents: 235 tokens (0.0%)
   Memory files: 28 tokens (0.0%)
   Skills: 4.9k tokens (0.5%)
   Messages: 8 tokens (0.0%)
   Compact buffer: 3k tokens (0.3%)
   Free space: 974k (97.4%)
4k tokens is 15-20kB. I'd ask you to paste that into a gist, but it might have sensitive data in it, because I suspect what you're seeing is not just the system prompt.
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mft_ 6 minutes ago
Apologies, you're right - I used imprecise terminology. The entire initial JSON structure that was sent from Claude Claude to the LLM at the start of a session was 162k. This included the system prompt together with a list of tools (some with very extensive explanations), MCP server details, etc.

I was simply supporting the article's data - their reported 33k tokens is probably roughly 150-165k.

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bel8 2 hours ago
And pi agent is even less.

The entire agent system prompt can be seen here:

https://github.com/earendil-works/pi/blob/main/packages%2Fco...

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mft_ 60 minutes ago
Maybe related to this minimalism, Pi doesn't come with most of the tools an LLM needs to function efficiently or effectively. I get that a blank slate is the paradigm, and you can add whatever you want, but it's too blank IMO.
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arcanemachiner 45 minutes ago
I have a functional Pi config, mostly self-made (it has everything I want, incl. subagents, web search, a /btw command, and other misc. addons), and my system prompt is ~3k.
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mft_ 24 minutes ago
Would you mind sharing?
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bel8 42 minutes ago
It's easy to add using plugins.

What do you miss? I ask because I do some heavy work with pi + GLM 5.2 (using opencode Go subscription) and my workflow is plan -> implement.

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mft_ 19 minutes ago
> It's easy to add using plugins.

Sure, but you have to add almost everything, no? It deliberately only comes with read, write, edit, and bash. My point wasn't that you can't add stuff, but that I'd just rather use an harness that's a bit more full featured from the start.

(Pi is a bit like old 3D printing where fettling the printer to work is a central part of the hobby. I'd rather just buy a Prusa.)

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azuanrb 53 minutes ago
[dead]
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ppeetteerr 38 minutes ago
Read through it an I'm curious whether setting the date and cmd on every system prompt call will cause the cache to invalidate.

I guess the cache would only be invalid if the day changed or the root directory, which would technically happen infrequently enough.

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anonym29 2 hours ago
If you really want a minimal agent that you heavily customize, just skip pi (130+ transitive dependencies on the "minimal" pi-coder package) and write your own. You learn a bunch, and it's not hard. You can even ask another LLM to help you get started.
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amunozo 3 minutes ago
Any tips on how to get started?
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tmalsburg2 35 minutes ago
I wrote my own harness in Emacs and it’s completely ridiculous how well it works. Auto-compact is the only missing feature on my list. Claude‘s approach, if I understand it correctly, invalidates a lot of cached context, and I‘m thinking about a more cache-friendly strategy.
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wolttam 42 minutes ago
This is a truly underrated approach IMO
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hackingonempty 17 minutes ago
Is it not a conflict of interest for a model provider to supply the harness? They are not motivated to minimize your costs.
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robbie-c 6 minutes ago
They sort of are, in that they want subscription users to have clients that behave well with the KV cache etc.

If you don't use a subscription, and pay per token instead, you can easily move to another harness.

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drtournier 2 hours ago
pi sends 1k (or less) -> https://github.com/earendil-works/pi/blob/main/packages/codi...

My $20 sub using gpt 5.6 sol thinking-off lasts for hours using pi.

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systima 58 minutes ago
We are yet to try Pi!
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tontinton 43 minutes ago
Mine sends even less - https://maki.sh
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tmalsburg2 26 minutes ago
Nice!

> When context gets too long, maki compacts history automatically: strips images, thinking blocks, and summarizes older turns.

Don’t the summaries of older turns effectively invalidate the context cache, such that you consume less tokens but more expensive tokens?

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dymk 21 minutes ago
Only once per compaction
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andai 49 minutes ago
With Fable being per token instead of on the subs (unless they changed it again?), I decided to test Claude code on OpenRouter where I had some credits, with Opus 4.8 and Fable 5.

I asked both a trivial question (summarize last commit). Opus cost 50 cents, Fable about $1.

That checks out because Fable's twice as much in the API (though I think its emphasis on correctness makes the difference larger for bigger tasks).

But, at $1 per question, I think I will stick to the subscription for now! I was certainly glad GPT-5.6-Sol is included in OpenAI's subscription, and I'm curious if they'll be able to do the same for GPT-6.

All the VC money appears to have run out a few weeks ago.

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andai 42 minutes ago
As for context size and harnesses I did make a trivial bash agent based on this "agent in 50 lines" tutorial[0] recently, and found that for trivial work, it was about an order of magnitude cheaper and faster.

I haven't tested it on anything bigger but it doesn't seem to do the kind of proactive testing, that they do in bigger harnesses.

Codex at least has a system prompt that tells it not to consider a feature a complete until it has verified it. I'm not sure about Claude Code.

I suppose I could add that one line to the prompt, and it would get me much closer to agi :) I think Fable does this proactively even without a prompt, but I haven't tested that yet.

If Fable in my own harness is significantly cheaper than Claude Code, that would be very appealing. (I could actually afford to use it for most things!) But I think most of the cost comes from the testing it does. So we'll have to see.

[0] https://minimal-agent.com/

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llm_nerd 41 minutes ago
Fable's subscription inclusion theoretically ends EOD today. Anthropic put a wishy-washy "if we have capacity we'll continue it" thing, and given how competitive GPT 5.6 Sol is, and it is included in OpenAI's subscription, I fully expect Anthropic to extend Fable or they will have a serious exodus on their hands.

Competition is good.

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SyneRyder 26 minutes ago
Anthropic have extended Fable access again to July 19. The notice should pop up in your Claude Code now when you start a new session (also announced on the ClaudeDevs X account first).
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luciana1u 43 minutes ago
Claude Code sending 33k tokens before reading the prompt is the AI equivalent of a consultant who bills you for the time spent reading your email before they even open it.
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estetlinus 42 minutes ago
Well, I have to open the lid on my computer and remember my password, no?
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docheinestages 54 minutes ago
I've been trying various harnesses like Pi, OpenCode, Qwen Code, and Nanocoder. A common problem I keep running into is failed tool calls, regardless of the model. What is the best harness and on-device model combination right now?
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wolttam 43 minutes ago
> and on-device model combination right now

That would depend entirely on what your device is. This sounds likely not to be an issue with the harness, but the capabilities of the models you've tried.

I experience almost no tool call failure using my nothing-special harness and DSv4 Flash.

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arcanemachiner 49 minutes ago
You can't afford the best model. What are your specs and what models + quants have you tried?

Qwen 3.6 35B A3B and Qwen 3.6 27B can both do reliable tool calls on Pi at Q4_K_M using llama.cpp

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PUSH_AX 44 minutes ago
This is like saying contractor (A) asked for $33,000 to undertake the work and contractor (B) asked for $7,000

Are we measuring and caring about the right thing?

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systima 43 minutes ago
Anecdotally, the results from OpenCode + Claude appear to be the same if not better for our uses over the past year.
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himanshumehra 16 minutes ago
that makes sense, claude code actually does inflates token usage
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skeledrew 34 minutes ago
I feel like this article isn't saying much. Even with tools disabled, Claude Code still has a crap load of commands and other things that Claude (the model) should know the availability of since it's optimized for them. All of that has to be disabled if this is to be a real harness comparison. And of course the system prompt can be completely replaced, making it a no-brainer to use a more minimal prompt similar to OpenCode. And beyond that nothing else really matters because the rest (cache behavior, etc) lies with the provider's platform, not the harness.
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token_roast 25 minutes ago
Why don't people fix their costs (rent a gpu) and just write their own harness (about 200 lines of code).

Supposed to be hacker news and half the posts are like "this harness steals this" like it cant be avoided.

These API costs are mad.

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echelon 18 minutes ago
GLM isn't good enough yet.

It pays to be marginally ahead of people stuck on open models.

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bigyabai 2 hours ago
I recommend that Opencode users try Dynamic Context Pruning as well: https://github.com/Opencode-DCP/opencode-dynamic-context-pru...

It works great for long-horizon tasks, and feels like it saves a boatload of tokens.

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verdverm 56 minutes ago
The Sleev (the project has been renamed to make a startup) creator was shilling their project in the OpenCode Discord. That person is very convinced they have something that no one has ever built before. They focused on token reduction without any real evals for capability impacts.

I'm generally against this context pruning without prompting or details. Sleev is very opaque about how it works and definitely will bust your cache.

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bigyabai 53 minutes ago
It's definitely not unprecedented, but the plugin version is useful. Sleev seems like a nothingburger, I'm happy with the results I get from DCP already.
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piokoch 2 hours ago
No surprise, I've noticed that "agents", not only CC (I am using Copilot) are trying to be "clever", searching for a lot of data. This is good for LLM providers as this eats a lot of tokens.
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arcanemachiner 36 minutes ago
OpenAI, to their credit, seems to be focusing pretty heavily on token efficiency in GPT 5.5 and beyond.
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slopinthebag 2 hours ago
Anthropic wants to produce the best coding agent possible and doesn’t care (is even incentivized) about high costs. Other harnesses have to make trade offs between performance and cost.
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goda90 60 minutes ago
Given they're incentivized to increase token use, what guarantees that higher token use improves the effectiveness of the agent and isn't just artificial padding?
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slopinthebag 52 minutes ago
Well, nothing really. But I assume there can be some benefits to modifying context. For example, updating file contents or marking them as modified, summarization, injecting additional information, removing irrelevant tool call results, etc.
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bpye 58 minutes ago
Is there evidence that it is actually a better agent though?
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slopinthebag 52 minutes ago
There’s evidence it’s a worse agent actually. I’m just saying in theory.
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nubg 46 minutes ago
So? it doesnt matter, after the first turn it's cached. We are probably talking about single digit cents.
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gokselu 18 minutes ago
[flagged]
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siddhxrth 52 minutes ago
[flagged]
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systima 49 minutes ago
We have never read your blog or your content before.

Suspect that many have covered the "Comparing agentic coding tools" angle before, and that the differentiator is depth of analysis + conclusions.

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anamexis 47 minutes ago
Do you think you were the first person to write a blog post about coding harness token usage?
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nish__ 25 minutes ago
Intellectual property is a dead concept.
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MallocVoidstar 2 hours ago
> Claude Code 2.1.207 and OpenCode 1.17.18, both pinned to claude-sonnet-4-5

So not only is this article AI-written, but the testing was entirely done by AI, too? I can't see any other reason to use such an old model.

> Our traffic passes through a local LLM gateway that wraps requests in its own envelope, a constant we measured at roughly 6,200 tokens with bare calibration requests

Why do you need to do calibration requests to figure out how your own gateway is affecting requests?

> Its subagent lane did not complete cleanly through our gateway

> We attempted to toggle extended thinking in both harnesses and are declining to publish numbers. Our gateway applies its own thinking policy, neither harness's toggle demonstrably survived the path, and anything we quoted would be noise.

Why is your own gateway screwing with your testing?

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systima 59 minutes ago
Model:

Cost, mainly. The runs went through a Claude Max subscription rather than metered API billing, and pinning an older stable snapshot kept run-to-run comparisons clean and cheap. The fixed harness payload (system prompt plus tool schemas), so the headline numbers shouldn't change too much.

That said, happy to re-run the matrix on Fable and publish the diff; payload figures should barely move, tool-calling behaviour might.

Gateway:

Meridian (github.com/rynfar/meridian); proxy that bridges the Claude Code SDK to a standard Anthropic endpoint so a Claude Max subscription can drive OpenCode-et-al.

It's the auth route for all agent traffic on the machine, not something built for the benchmark.

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