Breaking down: "A Node backend loses the response to a Stripe POST. Use https://docs.stripe.com/api/idempotent_requests to write a small retry decision table for a lost response, a received HTTP 500, changed parameters, and a key older than 24 hours. State when to retain the original key and what the API stores. Separate facts from our proposed application policy. Do not imply that a timeout proves no charge occurred."

Identified 8 research target(s) to investigate; these are not established facts

Deep mode: up to 4 paid/cached/public reads plus one bounded gap-expansion pass when needed.

Web search: 4/4 planned queries attempted, 3 succeeded, 11 public page previews, 1 unavailable queries. Snippets are discovery only. Public reads spend no USDC; model and service operating costs remain separate.

Discovered 0 verified creator source(s) and 11 free public reference(s)

Claim-aware portfolio (exhaustive; bounded selection, not a claim of global optimality) selected 1/1 positive proposal(s): 1 free/cache selections + 0 paid fresh selections, predicting 8/8 claim(s) above the evidence floor with $0.000000/$0.015000 fetch USDC reserved.

Free-preview pre-check maps an actionable source to every sub-claim (8/8); paid reading may proceed within the budget.

READ Idempotent requests | Stripe API Reference - selected original public page, 0 USDC; not a cache hit.

Read extracted public text from https://docs.stripe.com/api/idempotent_requests - S1; quote matching establishes source grounding, not fact verification.

Sub-claim "According to https://docs.stripe.com/api/idempotent_requests…": 100% covered by S1 — S1 explicitly states Stripe saves the resulting status code and body of the first request for any given idempotency key, and that keys can be removed automatically after they are at least 24 hours old.

Sub-claim "According to https://docs.stripe.com/api/idempotent_requests…": 40% covered by S1 — S1 says subsequent requests with the same key return the same result, which supports retrying with the same key, but it does not explicitly address a lost/no-response scenario or state the client action for that case.

Sub-claim "According to https://docs.stripe.com/api/idempotent_requests…": 70% covered by S1 — S1 directly states subsequent requests with the same key return the same result, including 500 errors, which implies retrying with the same key returns the stored 500 result; it does not give a separate explicit client instruction for HTTP 500.

Sub-claim "According to https://docs.stripe.com/api/idempotent_requests…": 100% covered by S1 — S1 explicitly states the idempotency layer compares incoming parameters to those of the original request and errors if they are not the same.

Sub-claim "According to https://docs.stripe.com/api/idempotent_requests…": 100% covered by S1 — S1 explicitly states keys can be removed automatically after at least 24 hours and a new request is generated if a key is reused after the original is pruned.

Sub-claim "According to https://docs.stripe.com/api/idempotent_requests…": 60% covered by S1 — S1 supports retaining the key for lost responses and HTTP 500 because subsequent requests with the same key return the same result, and supports not reusing it after pruning or with changed parameters; however, it does not phrase this as an explicit retention rule for each listed case.

Sub-claim "What does Stripe document about whether a timeout or lost re…": 30% covered by S1 — S1 shows Stripe stores the result of the first request and returns the same result on retry, which is relevant context, but it does not directly state whether a timeout or lost response proves no charge occurred.

Sub-claim "What proposed application policy should the Node backend fol…": 0% covered — No supplied passage proposes an application policy for the Node backend; this is a synthesis task not answered by the gathered Stripe documentation.

Coverage is adequate for the core documented Stripe facts: storage duration, changed parameters, and key older than 24 hours are directly answered. The lost-response and HTTP 500 client-action items are partially covered by the same-key retry behavior, and the proposed application policy is a synthesis task not expected from the Stripe reference. Remaining budget is only 0.015, so no affordable skipped source can be recommended.

Final check — "According to https://docs.stripe.com/api/idempotent_requests…": 100% assessed by S1

Final check — "According to https://docs.stripe.com/api/idempotent_requests…": 40% assessed by S1

Final check — "According to https://docs.stripe.com/api/idempotent_requests…": 50% assessed by S1

Final check — "According to https://docs.stripe.com/api/idempotent_requests…": 100% assessed by S1

Final check — "According to https://docs.stripe.com/api/idempotent_requests…": 100% assessed by S1

Final check — "According to https://docs.stripe.com/api/idempotent_requests…": 40% assessed by S1

Final check — "What does Stripe document about whether a timeout or lost re…": 30% assessed by S1

Final check — "What proposed application policy should the Node backend fol…": 0% assessed

Final coverage assessment — The supplied excerpt from Stripe's idempotent requests documentation directly answers the factual sub-claims about what Stripe stores, how long keys are retained, behavior on retry with changed parameters, and key reuse after pruning. It does not provide a specific client procedure for a lost response or HTTP 500 beyond the general statement that subsequent requests with the same key return the same result, including 500 errors. It also does not state that a timeout or lost response proves no charge occurred. The proposed application policy is not present in the source and must be supplied separately by the user. The assessment does not establish a complete supported answer for every requested part.

Synthesizing a grounded answer from 1 source(s)…

Relevance review returned; only checked excerpts can retain support, and review cannot raise it.

Delivering qualified source excerpts; complete synthesis and per-assertion support remain unverified.

Source-matched public excerpt (no creator reward) — S1, research target 1, proposed support 90% (estimate, not entailment): “Stripe’s idempotency works by saving the resulting status code and body of the first request made for any given idempotency key, regardless …”

Source-matched public excerpt (no creator reward) — S1, research target 1, proposed support 80% (estimate, not entailment): “You can remove keys from the system automatically after they’re at least 24 hours old.”

Below support/reward gate — S1, research target 2, proposed support 30% (estimate, not entailment): “A client generates an idempotency key, which is a unique key that the server uses to recognize subsequent retries of the same request.”

Source-matched public excerpt (no creator reward) — S1, research target 3, proposed support 40% (estimate, not entailment): “Subsequent requests with the same key return the same result, including 500 errors.”

Source-matched public excerpt (no creator reward) — S1, research target 4, proposed support 100% (estimate, not entailment): “The idempotency layer compares incoming parameters to those of the original request and errors if they’re not the same to prevent accidental…”

Source-matched public excerpt (no creator reward) — S1, research target 5, proposed support 50% (estimate, not entailment): “You can remove keys from the system automatically after they’re at least 24 hours old.”

Source-matched public excerpt (no creator reward) — S1, research target 5, proposed support 80% (estimate, not entailment): “We generate a new request if a key is reused after the original is pruned.”

Below support/reward gate — S1, research target 6, proposed support 30% (estimate, not entailment): “A client generates an idempotency key, which is a unique key that the server uses to recognize subsequent retries of the same request.”

Below support/reward gate — S1, research target 6, proposed support 30% (estimate, not entailment): “Subsequent requests with the same key return the same result, including 500 errors.”

Below support/reward gate — S1, research target 7, proposed support 20% (estimate, not entailment): “Stripe’s idempotency works by saving the resulting status code and body of the first request made for any given idempotency key, regardless …”

Below support/reward gate — S1, research target 8, proposed support 10% (estimate, not entailment): “A client generates an idempotency key, which is a unique key that the server uses to recognize subsequent retries of the same request.”

Below support/reward gate — S1, research target 8, proposed support 10% (estimate, not entailment): “Subsequent requests with the same key return the same result, including 500 errors.”

Below support/reward gate — S1, research target 8, proposed support 10% (estimate, not entailment): “The idempotency layer compares incoming parameters to those of the original request and errors if they’re not the same to prevent accidental…”

Below support/reward gate — S1, research target 8, proposed support 10% (estimate, not entailment): “You can remove keys from the system automatically after they’re at least 24 hours old.”

Below support/reward gate — S1, research target 8, proposed support 10% (estimate, not entailment): “We generate a new request if a key is reused after the original is pruned.”

Prepared source excerpts citing 1 source(s); complete synthesis is unverified

Confidence: Low — Only source excerpts are delivered; complete synthesis and per-assertion support remain unverified. Evidence assessment: 4 sub-claims remain below the evidence threshold.

stripe.com contributed 100% - free public reference; reward share withheld

Done. Spent $0 across 0 confirmed/simulated payment(s) to creators.