fix(anthropic): move oversized OAuth system prompt to user prefix - #13609
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fix(anthropic): move oversized OAuth system prompt to user prefix#136090xyg3n wants to merge 1 commit into
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OAuth subscription requests (Claude Code route) fail with 400 'You're out of extra usage. Add more at claude.ai/settings/usage' when the system field contains large custom content beyond the CC identity block. The same payload succeeds with a pay-per-token API key, so the check is subscription-route specific and orthogonal to quota. Fix: keep only the CC identity block in system and fold any extra system blocks into a [CONTEXT]...[/CONTEXT] user-message prefix followed by an assistant 'Understood.' acknowledgement. Content is preserved verbatim; only the transport slot changes. Tested on 0.10.0 (commit b2111a2) with Opus 4.7 OAuth and a SOUL-style ~3k-token system prompt: 400 -> 200 with response latency unchanged.
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Closing to re-open from a clean branch after commit metadata fix. Replacement PR incoming. |
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Problem
OAuth / Claude Code subscription requests via
anthropic_messagesfail with a 400 when the system field contains custom content beyond the CC identity block:The error wording points at quota, but the account actually has usage available — the same payload sent directly with a pay-per-token API key returns 200. The check is specific to the OAuth / subscription route and is triggered by the size/content of
systemonce it goes beyond the basic CC identity string.This breaks any downstream that ships a non-trivial system prompt (custom agents, SOUL-style personas, extended tool guides) while using a Claude Code subscription token.
Fix
Keep only the CC identity block in
systemand fold any additional system blocks into a[CONTEXT]...[/CONTEXT]user-message prefix followed by an assistantUnderstood.acknowledgement. Content is preserved verbatim — only the transport slot changes.The change is inside the existing
if is_oauth:branch inbuild_anthropic_kwargs, so it only affects OAuth code paths. Non-OAuth requests (x-api-key, Bedrock, third-party Anthropic-compat endpoints) are untouched.Test
Reproduced and verified against the Anthropic API on the latest main (
b2111a2b):400 invalid_request_errorwith the quota text.system+ rest in[CONTEXT]user prefix →200, response text identical, latency unchanged.Integration tested in a production Hermes 0.10.0 deployment running Opus 4.7 via OAuth with a ~3k-token SOUL-style system prompt: 400 errors cleared, message flow back to normal (4 api_calls / 36s on a cold session with tools).
No changes to non-OAuth paths. No behavioural change expected for users with
systemcontaining only the CC identity block.