# Request lifetime is not durability

> For agents: start with the [agent guide](https://ratstack.sh/llms.txt). Every page is Markdown by default; add `Accept: text/html` for HTML.

Free workshop: [Build Agent Loops That Never Stop Shipping](/tokenmaxx#interested).

A bounded request pass and a durable recovery record solve different problems. On HTTP Workers, waitUntil extends execution for up to 30 seconds after response or disconnect; that allowance is shared.

Book basis: [B4](/lore/durability-bibliography#b4-release-it), [B6](/lore/durability-bibliography#b6-fundamentals-of-data-engineering).

## Failure it prevents

Three 20-second attempts plus delays need more time than the post-response allowance, so background delivery is cut off without recovery.

## Our Effect 4.0.0 reading

Use one deadline for the pass and cap every attempt at remaining time. `Context.Reference` can hold an intentional default budget. Do not cache an absolute deadline in it. Persist an undelivered marker for independent redrive.

Source: `packages/effect/src/Context.ts`, `packages/effect/src/Effect.ts`.

## How to check

Use a 25-second example budget. Cancel post-response work, then redrive the persisted marker with the same operation identity and prove duplicate safety. This check is our proposal. The books do not prescribe it.

Continue with [Timeouts bound waiting](/lore/timeouts-bound-waiting), [Retry needs idempotent effects](/lore/retry-needs-idempotency).

Connect this to [the existing rat-stack guidance](/lore/concurrent-work-needs-an-owner).

Use [the durability skill](/skills/durability) for the full review. Return to [the durability index](/lore/durability).

## Sources

1. [Nygard, Michael T. Release It!: Design and Deploy Production-Ready Software. Pragmatic Bookshelf, 2007.](https://archive.org/details/releaseitdesignd0000nyga)
   Pragmatic Bookshelf. §4.4 Unbounded Result Sets; Chapter 5 Stability Patterns: §5.1 Timeouts, §5.2 Circuit Breaker, §5.3 Bulkheads, §5.4 Steady State, §5.5 Fail Fast, §5.6 Handshaking, §5.7 Test Harness, §5.8 Decoupling Middleware. Accessed 2026-10-23.

2. [Reis, Joe; Housley, Matt. Fundamentals of Data Engineering. O’Reilly.](https://www.oreilly.com/library/view/fundamentals-of-data/9781098108298)
   O’Reilly. Part II, Chapter 5: Message Queues; DataOps considerations; Incident Response. Accessed 2026-10-23.

3. [Effect contributors. Effect 4.0.0. Context.ts](https://github.com/Effect-TS/effect/blob/67ba4e46a11ccda0b6761578bfd22c04ae00167d/packages/effect/src/Context.ts)
   Effect-TS. Pinned source for our Effect mapping, not a claim from the book. Accessed 2026-10-23.

4. [Effect contributors. Effect 4.0.0. Effect.ts](https://github.com/Effect-TS/effect/blob/67ba4e46a11ccda0b6761578bfd22c04ae00167d/packages/effect/src/Effect.ts)
   Effect-TS. Pinned source for our Effect mapping, not a claim from the book. Accessed 2026-10-23.

5. [Cloudflare Workers Context: waitUntil](https://developers.cloudflare.com/workers/runtime-apis/context/)
   Cloudflare. HTTP-triggered waitUntil extends execution for up to 30 seconds after response or disconnect; calls share this allowance. This is a platform reference, not book lore. Accessed 2026-10-23.

## Lore on this page

- [Dead letters need a return path](/lore/dead-letters-need-a-return-path)

## Linked from

- Agent guide → An Effect stack so pure (aspirational) Kit Langton will blush. → [Read page](https://ratstack.sh/llms.txt)

- Change log → What changed in the files served here, newest first. → [Read page](https://ratstack.sh/log)

- durability → Keep a rat-stack app standing when a provider, pool, or dependency slows down or a worker dies. Use at any I/O boundary, connection pool, provider call, shared waiter, fan-out, flag, gate, or work that can outlive a request, or when asked "what happens when this is slow", "add a timeout", "make this durable", or "what survives a crash". → [Read page](https://ratstack.sh/skills/durability)

- Durability starts with a recovery record → A reading order for storage, replay, worker ownership, overload, and recovery tests. → [Read page](https://ratstack.sh/lore/durability)

- Full agent guide → An Effect stack so pure (aspirational) Kit Langton will blush. → [Read page](https://ratstack.sh/llms-full.txt)

- Rat Stack lore | rat-stack → Short, source-grounded notes on the ideas and decisions behind rat-stack. → [Read page](https://ratstack.sh/lore)

- Source change history (log.md) → The generated change log as Markdown. → [Read page](https://ratstack.sh/log.md)