Inflight Concurrency Cap Bypass on Streaming Bodies #1666

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1. mishushakov commented on Aug 19, 2026

   

   mishushakov

   on Aug 19, 2026

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   /sdk draft
2. devin-ai-integration

   added

   bugSomething isn't workingSomething isn't working

   sdkImprovements or additions to SDKsImprovements or additions to SDKs

   on Aug 19, 2026
3. devin-ai-integration commented on Aug 19, 2026

   

   devin-ai-integrationBot

   on Aug 19, 2026 – with Devin.ai Integration

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   Triage

   • type: bug
   • priority: medium
   • complexity: small
   • affected_area: js-sdk / api inflight concurrency limiter
   • actionable: yes
   • needs_clarification: false
   • summary: limitConcurrency releases its semaphore on response headers rather than body completion, letting streaming requests bypass the inflight cap and exhaust HTTP/2 streams (matches the TODO in js-sdk/src/api/inflight.ts).

   Written by Devin
4. devin-ai-integration commented on Oct 13, 2026

   

   devin-ai-integrationBot

   on Oct 13, 2026 – with Devin.ai Integration

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   @ujjwalredd thanks for reporting this. It's fixed in e2b@2.56.0 (JS SDK) by #1733, which supersedes #1717. That PR removes the SDK-level in-flight cap (limitConcurrency in inflight.ts) entirely, so there's no slot accounting left to bypass. The SDK now depends only on undici@^8, which respects the server's HTTP/2 SETTINGS_MAX_CONCURRENT_STREAMS and opens more connections instead of hitting ERR_HTTP2_TOO_MANY_CONCURRENT_STREAMS.

   Heads-up, this is a breaking change: the E2B_*_INFLIGHT_REQUESTS env vars are gone, and the SDK now requires Node.js >= 22.19.0.

   Upgrade: npm i e2b@2.56.0

   Written by Devin
5. devin-ai-integration

   closed this as completedon Oct 13, 2026