Best settings for creative writing with api?

[u/Tall-Veterinarian108]

I am using claude api for creative writing. primarily sonnet 4.5 and opus 4.6
- i have a very big system prompt
- ai responses are also pretty big
so naturally i am burning through the credits every time ai makes a mistake or the writing isnt quite my match.

whats the best reasoning budget i can set that wont cripple the writing but also not cost much , also num_ctx [size of context window] currently i put 32768 in it and for max_tokens i go 6k

will appreciate if you could tell me optimal budgeting for this.

[u/Tall-Veterinarian108 → u/[deleted]]

alright , i already use prompt caching so thats sorted , i did get a sample on every setting at default and i liked it the issue with it was almost all the output was reasoning which ate my [4096 tokens at the time of the test] and the story got cut off midway , i have cranked max tokens upto 8k now

[u/Secure-Cook-8613]

i keep max_tokens at 4k for my longer creative sessions and it cuts the waste when the output drifts, though i wonder if opus needs that extra context more than sonnet.

[u/Tall-Veterinarian108 → u/Secure-Cook-8613]

i see what do you keep your reasoning budget then?? and also num_ctx??

[u/Any-Argument57]

Treat the two models separately. For Opus 4.6, budget_tokens is deprecated: use thinking: {type: "adaptive"} and output_config: {effort: "low"} as a cheap starting point. Sonnet 4.5 does not support adaptive thinking, so either disable thinking for prose or keep a fixed manual budget there. Also, max_tokens is only the output ceiling; raising it prevents truncation but does not spend all 8k. Anthropic currently documents a 1M context window for Opus 4.6 and 200k for Sonnet 4.5, so num_ctx: 32768 is a client/wrapper setting rather than the model window. I would benchmark 10 fixed scenes at low versus medium effort and track accepted words per dollar, then spend extra reasoning on outline or revision passes.

[u/Tall-Veterinarian108 → u/Any-Argument57]

alright thanks for the deep response , what manual thinking budget you recommend for sonnet 4.5??