Hacktoberfest 2026: le issue che i maintainer hanno segnato per ottobre, aperte e adatte ai principianti. Sfoglia le issue Hacktoberfest

Custom "anthropic" provider does not enforce provider.max_prompt_tokens — sessions grow past the model context window until a hard 400

Aperta
  • Qualcosa non va?
#2,355 1 commento 0 reazioni 0 assegnatari Vedi su GitHub

I maintainer di solito rispondono entro 1 giorno

Nessuno ha ancora preso questa issue.

Valutazione

Difficoltà
4/5
Tempo stimato
3-5 giorni
Idoneità per principianti
48/100
Tipo di issue
Bug
Chiarezza
Abbastanza chiara
Stato di attività
Attiva
Stack tecnologico
java
Ambito
api, backend

Direzione di ricerca

Parti dal percorso session-create/resume del provider anthropic personalizzato e traccia come vengono gestiti max_prompt_tokens e le soglie di infinite_sessions prima dell’invio delle richieste. Confronta questo percorso con quello del backend Copilot, dove la compattazione funziona, riproduci la trascrizione crescente e conferma che i prompt rimangano entro il budget configurato e che le sessioni non riuscite possano recuperare.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

bug

Summary

When a custom provider of type: "anthropic" is configured with max_prompt_tokens, the SDK does not appear to enforce that budget. A long-running session keeps accumulating transcript until the request exceeds the model's context window and the provider rejects it with HTTP 400 -- after which the session is permanently unusable.

Configuration

The provider is created on every session create/resume with an explicit prompt budget:

{
  "type": "anthropic",
  "base_url": "...",
  "model_id": "claude-sonnet-5",
  "max_output_tokens": 32768,
  "max_prompt_tokens": 967232
}

max_prompt_tokens is derived as context_window (1,000,000) - max_output_tokens (32,768) = 967,232.

Expected

The SDK compacts (or otherwise bounds the prompt) before crossing max_prompt_tokens = 967232.

Actual

The transcript grew unbounded to 1,001,142 tokens -- 33,910 past the configured budget, and past the model's 1,000,000 hard limit:

400 invalid_request_error
"prompt is too long: 1001142 tokens > 1000000 maximum"

The session had run ~18 successful turns over ~3 hours, with the serialized request growing steadily (~1.98 MB -> ~2.04 MB) before crossing the limit. Tool count was constant throughout, so the growth is accumulated conversation history rather than tool schemas.

Two additional observations

  1. infinite_sessions thresholds also appear inert on this path. background_compaction_threshold / buffer_exhaustion_threshold are sent on every turn but appear to have no effect for the anthropic provider (they do take effect on the Copilot backend path). So neither the threshold-based compaction nor the max_prompt_tokens budget bounded the transcript.

  2. The session actively degrades after the first failure. Once over the limit, continued turns keep appending to the transcript -- request size grew from ~2.044 MB to ~2.065 MB across ~30 consecutive failed turns. There is no back-off, trim, or compaction triggered by the 400, so the session can never self-recover; every subsequent turn fails immediately (~1.5s vs. the 38s first failure).

Impact

Every turn in an affected session fails permanently. The only recovery is to start a new session, and nothing in the surfaced error indicates that to the user. Because the failure is a deterministic 400, retry suppression correctly kicks in -- but that just means the session is durably wedged.

Environment

  • SDK 1.0.7 / Copilot CLI 1.0.71
  • Custom anthropic provider over an OpenAI-incompatible relay endpoint
  • Model claude-sonnet-5 (1,000,000-token context window)

Ask

Should provider.max_prompt_tokens be enforced on the anthropic provider path (and/or should infinite_sessions compaction apply there)? If enforcement is intentionally backend-only today, it would help to document that clearly, since the field is accepted without warning and silently has no effect.

Lingua principale
TypeScript
Stelle
10.5k
Fork
1.5k
Merge medio
1g 7h
PR unite (30g)
98

Preparare l'ambiente

Apri in Codespaces

Avvia il container di sviluppo del progetto nel browser, con il tuo account GitHub.

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di github/copilot-sdk

Tutte le issue di github/copilot-sdk

Issue simili

Altre issue su TypeScript

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.