[RaviTharuma]

Summary

• promote byte-light chat requests into the existing heavyweight lease when message, tool, or conservative token-cost thresholds are crossed
• reject pathological histories above a configurable hard message cap with a structured compact-required 413
• bound structural inspection by nodes and depth, conservatively treating exhausted inspection as heavyweight
• preserve the existing actual-byte ingestion and exactly-once lease lifecycle

Scope

This is the smallest native structure-aware admission slice for the release branch. It deliberately reuses the existing immediate retryable 503 behavior rather than retaining parsed requests in a new in-process queue. Queueing, cgroup recovery gating, and metrics remain follow-up scheduler work.

Tests

• node --import tsx/esm --import ./open-sse/utils/setupPolyfill.ts --test tests/unit/chat-body-admission.test.ts tests/unit/chat-completions-parse-once-7847.test.ts — 23 passed
• git diff --check — passed
• npm run test:coverage — blocked before tests by the shared Node 26 dependency install (yargs CommonJS entry throws require is not defined)
• npm run typecheck:core — blocked by missing installed modules (safe-regex, @toon-format/toon, omniglyph, sql.js, ioredis, js-tiktoken)
• npm run check:docs-all — changed env vars are synchronized; repository baseline still reports unrelated missing GROK_AUTH_PATH / OMNIROUTE_VNC_CONTAINER_VNC_PORT entries

Changed test file: tests/unit/chat-body-admission.test.ts.

Coverage result: unavailable because the coverage runner fails during c8 startup under the current Node 26/shared dependency environment, before test execution.

Closes #8276

[RaviTharuma]

Rebased the branch onto the latest release/v3.8.49 after the base-drift warning. Verification immediately before push:

upstream...HEAD: 0 behind / 1 ahead
5 files changed, 309 insertions(+), 2 deletions(-)
.env.example
docs/reference/ENVIRONMENT.md
src/app/api/v1/chat/completions/route.ts
src/shared/middleware/chatBodyAdmission.ts
tests/unit/chat-body-admission.test.ts

The diff contains only the focused #8276 implementation/tests/docs. Also incorporated review hardening: bounded object iteration, fail-heavy inspection exhaustion, schema-key accounting, and conservative non-ASCII token estimation. Focused suite: 26 passed.

[RaviTharuma]

CI note: the failing fast-path shards include repository-wide baseline failures outside this PR’s changed files (for example DashScope video assertions appear on multiple unrelated PRs). The focused tests listed in this PR body pass locally. I am still checking for any failure attributable to this patch.

[diegosouzapw]

Thanks, @RaviTharuma! 🙏 Merged — structure-aware chat admission middleware (validates request body shape before dispatch). Rebased onto the current release tip; 22/22 admission tests green.