RunHaiku 4.5repeat 2

Gated-execute on HTTP 301 vs 308

claude-haiku-4-5-20251001__gated-execute__research-http-redirects__r2

Score

0.917

wrong answer

design ran as designed

Cost: $0.063; + $0.050 judging
Latency: 29.6s; setup 0.0s, grading 4.7s
Turns: 14
Tool calls: 13
Subagents: 0
Tokens in / out: 84k / 2.9k; 60,953 read from cache

Did the design run?

every check held

Run completed: heldharness.run-completedThe environment was built, the architecture returned and grading finished, none of them throwing.
No API failures: heldharness.apiNo model call failed at the API.
Every call ended: heldharness.calls-endedEvery call ended with a result, or was stopped by the run's own limits.
No harness tool denied: heldharness.harness-toolsThe sandbox guard never denied a harness tool, nor a tool the session itself offered.
Tool servers connected: heldharness.mcp-connectedEvery tool server the harness gave a call was connected when the session started.
No foreign tool servers: heldharness.mcp-hermeticNo call loaded a tool server the harness did not give it.
Builtin tools: heldharness.builtin-toolsA check recorded with the run.
Structured replies arrived: heldharness.structured-outputEvery call that asked for structured output and ran to the end got it.
No silent fallbacks: heldharness.not-degradedNo phase fell back on a default (an empty plan, a default winner) instead of its output.
Judge answered: heldharness.judgeAt least one grading call returned a usable verdict.
Every state change was reviewed: heldgated-execute.reviewedEvery call that changed the world had been allowed by a review before it ran, counted from the world’s own journal.
Every decision was read: heldgated-execute.decisionsEvery review that ran to its end gave its decision through the schema; an unreadable one is a denial.
Each call was shown the right tools: heldgated-execute.toolsThe executor was shown the task’s full toolset and each reviewer the read-only tools.

Phases

Spend$0.063

Drawn from the phase records: timing and cost per call, no tool calls or messages.

Phase	Duration	Cost	Turns	Tools	Model
Execute	29.6s	$0.063	14	13	claude-haiku-4-5-20251001

The call-by-call replay is not published for this run. Traces are large, so the repository keeps 9 of this run set’s 900 and leaves the rest out; the score, phases and final answer on this page come from the committed run record.

Runs you can replay

A gate that blocked the right moveGated-execute · Haiku 4.5
Three proposals beat one agentPropose-select · Haiku 4.5
A verifier that earned its keepPlan-execute-verify · Sonnet 5.5
A revision that did not helpPlan-execute-verify · Haiku 4.5
The control, missing a stepSingle · Haiku 4.5

Record this cell yourself: npm run bench -- run --strategies gated-execute --tasks research-http-redirects --models claude-haiku-4-5-20251001 --repeats 1

Score breakdown

partialStates that 301 is "Moved Permanently" and 308 is "Permanent Redirect", and that both indicate the target resource has been assigned a new permanent URI.
0.50weight 0.17
partial, backed by verified evidence E5, E6. “**308 Permanent Redirect** also indicates that the requested resource has been assigned a new permanent URI.”
passStates that a client following a 308 must not change the request method: a POST is repeated as a POST, with its body.
1.00weight 0.25
met, backed by verified evidence E2, E7. “the user agent MUST NOT change the request method when performing the redirect. This means if a client sends a POST request and receives a 308, the subsequent request to the new location must also be a POST request, preserving both the method and the request …[truncated 7 chars]
passStates that when following a 301 a user agent MAY change the request method from POST to GET (for historical reasons), which is the behaviour 308 exists to rule out.
1.00weight 0.25
met, backed by verified evidence E1, E7. “the specification explicitly permits user agents to change the request method from POST to GET when following a 301 redirect”
passStates that both 301 and 308 responses are heuristically cacheable, i.e. a cache may reuse them by default unless the method definition or explicit cache controls say otherwise.
1.00weight 0.17
met, backed by verified evidence E3, E4. “A 301 response is heuristically cacheable by default.”
passStates that both codes are currently specified in RFC 9110 (HTTP Semantics), and that 308 was originally defined in RFC 7538, which RFC 9110 obsoletes.
1.00weight 0.17
met, backed by verified evidence E8, E9, E10. “Status code 308 was introduced in RFC 7538 in April 2015 and is now also incorporated into RFC 9110.”

Penalties

No penalties were applied.

Scorer metadata

corpus: {"version":2,"snapshot":"2026-10-01","hash":"25fbed79c4f7f9e1b850436e0e4872f8e25dd80142f3177231c456f21817b817","documents":8}
opened documents: ["mdn-status-301","mdn-status-308","rfc7538","rfc9110","rfc7231"]
opened by role: {"secondary":["mdn-status-301","mdn-status-308"],"superseded":["rfc7538","rfc7231"],"primary":["rfc9110"]}
displayed share: {"mdn-status-308":1,"mdn-status-301":1,"rfc7538":0.782,"rfc9110":0.049,"rfc7231":0.0434}
cited count: 3
verified count: 3
hallucinated count: 0
citation integrity: 1
hallucinated urls: []
evidence block: true
evidence block repaired: false
evidence count: 10
verified quote count: 10
verified quote rate: 1
evidence: [{"url":"https://www.rfc-editor.org/rfc/rfc9110.html","claim":"301 Moved Permanently allows user agents to change the request method from POST to GET","quote":"For historical reasons, a user agent MAY change the request method from POST to GET for the subsequent request.","verified":true,"document":"rfc9110"},{"url":"https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/308","claim":"308 Permanent Redirect requires the request method to not be changed","quote":"The request method and the body will not be modified by the client in the redirected request.","verified":true,"document":"mdn-status-308"},{"url":"https://www.rfc-editor.org/rfc/rfc9110.html","claim":"301 is heuristically cacheable by default","quote":"A 301 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls","verified":true,"document":"rfc9110"},{"url":"https://www.rfc-editor.org/rfc/rfc9110.html","claim":"308 is heuristically cacheable by default","quote":"A 308 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls","verified":true,"document":"rfc9110"},{"url":"https://www.rfc-editor.org/rfc/rfc9110.html","claim":"301 Moved Permanently indicates the target resource has been permanently moved to a new URI","quote":"The 301 (Moved Permanently) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs.","verified":true,"document":"rfc9110"},{"url":"https://www.rfc-editor.org/rfc/rfc9110.html","claim":"308 Permanent Redirect indicates the target resource has been assigned a new permanent URI","quote":"The 308 (Permanent Redirect) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs.","verified":true,"document":"rfc9110"},{"url":"https://www.rfc-editor.org/rfc/rfc7538.html","claim":"308 was created to provide a permanent redirect without allowing method change, unlike 301","quote":"This status code is similar to 301 (Moved Permanently) ([RFC7231], Section 6.4.2), except that it does not allow changing the request method from POST to GET.","verified":true,"document":"rfc7538"},{"url":"https://www.rfc-editor.org/rfc/rfc9110.html","claim":"301 is specified in RFC 9110","quote":"15.4.2. 301 Moved Permanently","verified":true,"document":"rfc9110"},{"url":"https://www.rfc-editor.org/rfc/rfc9110.html","claim":"308 is specified in RFC 9110","quote":"15.4.9. 308 Permanent Redirect","verified":true,"document":"rfc9110"},{"url":"https://www.rfc-editor.org/rfc/rfc7538.html","claim":"308 was introduced in RFC 7538 in April 2015","quote":"The Hypertext Transfer Protocol Status Code 308 (Permanent Redirect)","verified":true,"document":"rfc7538"}]
judge unverified quotes: 0
judge verdicts: [{"names":{"status":"met","support":["E5","E6"]},"method-preserved-308":{"status":"met","support":["E2","E7"]},"method-change-301":{"status":"met","support":["E1","E7"]},"cacheable":{"status":"met","support":["E3","E4"]},"specifications":{"status":"met","support":["E8","E9","E10"]}},{"names":{"status":"partial","support":["E5","E6"]},"method-preserved-308":{"status":"met","support":["E2","E7"]},"method-change-301":{"status":"met","support":["E1","E7"]},"cacheable":{"status":"met","support":["E3","E4"]},"specifications":{"status":"met","support":["E8","E9","E10"]}},{"names":{"status":"partial","support":["E5","E6"]},"method-preserved-308":{"status":"met","support":["E2"]},"method-change-301":{"status":"met","support":["E1","E7"]},"cacheable":{"status":"met","support":["E3","E4"]},"specifications":{"status":"partial","support":["E8","E9","E10"]}}]
judge failures: 0
grounded weight share: 1

Final answer

Now I have all the information I need to provide a comprehensive answer. Let me compile it:

Answer

HTTP status codes 301 and 308 are both permanent redirect responses, but they differ significantly in how clients should handle the request method and body when following the redirect.

301 Moved Permanently indicates that the requested resource has been permanently moved to a new URI. For historical reasons, the specification explicitly permits user agents to change the request method from POST to GET when following a 301 redirect, though the specification also notes this behavior is often incorrect. A 301 response is heuristically cacheable by default.

308 Permanent Redirect also indicates that the requested resource has been assigned a new permanent URI. However, it differs critically in that the user agent MUST NOT change the request method when performing the redirect. This means if a client sends a POST request and receives a 308, the subsequent request to the new location must also be a POST request, preserving both the method and the request body. A 308 response is also heuristically cacheable by default.

The key practical difference is that 301 has a loophole for method conversion due to historical implementation practices, while 308 was specifically created to provide a permanent redirect that strictly preserves the request method, making it the preferred choice when you need to guarantee method preservation during a permanent redirect.

Regarding current specifications: 301 was originally defined in RFC 7231 and is now part of RFC 9110 (which obsoletes RFC 7231). Status code 308 was introduced in RFC 7538 in April 2015 and is now also incorporated into RFC 9110.

Evidence

{"evidence": [{"claim": "301 Moved Permanently allows user agents to change the request method from POST to GET", "quote": "For historical reasons, a user agent MAY change the request method from POST to GET for the subsequent request.", "url": "https://www.rfc-editor.org/rfc/rfc9110.html"}, {"claim": "308 Permanent Redirect requires the request method to not be changed", "quote": "The request method and the body will not be modified by the client in the redirected request.", "url": "https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/308"}, {"claim": "301 is heuristically cacheable by default", "quote": "A 301 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls", "url": "https://www.rfc-editor.org/rfc/rfc9110.html"}, {"claim": "308 is heuristically cacheable by default", "quote": "A 308 response is heuristically cacheable; i.e., unless otherwise indicated by the method definition or explicit cache controls", "url": "https://www.rfc-editor.org/rfc/rfc9110.html"}, {"claim": "301 Moved Permanently indicates the target resource has been permanently moved to a new URI", "quote": "The 301 (Moved Permanently) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs.", "url": "https://www.rfc-editor.org/rfc/rfc9110.html"}, {"claim": "308 Permanent Redirect indicates the target resource has been assigned a new permanent URI", "quote": "The 308 (Permanent Redirect) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs.", "url": "https://www.rfc-editor.org/rfc/rfc9110.html"}, {"claim": "308 was created to provide a permanent redirect without allowing method change, unlike 301", "quote": "This status code is similar to 301 (Moved Permanently) ([RFC7231], Section 6.4.2), except that it does not allow changing the request method from POST to GET.", "url": "https://www.rfc-editor.org/rfc/rfc7538.html"}, {"claim": "301 is specified in RFC 9110", "quote": "15.4.2. 301 Moved Permanently", "url": "https://www.rfc-editor.org/rfc/rfc9110.html"}, {"claim": "308 is specified in RFC 9110", "quote": "15.4.9. 308 Permanent Redirect", "url": "https://www.rfc-editor.org/rfc/rfc9110.html"}, {"claim": "308 was introduced in RFC 7538 in April 2015", "quote": "The Hypertext Transfer Protocol Status Code 308 (Permanent Redirect)", "url": "https://www.rfc-editor.org/rfc/rfc7538.html"}]}

Provenance of the numbers on this page

run set: scaffold-or-scale-v1
models: Haiku 4.5, Sonnet 5.5, Opus 5.5
effort: high
repeats: 2
fixtures: replay
runs: 900 / 900
strategy cost: $354.44
judge cost: $9.19
wall clock: 9h 48m
git: fce5807b2d

Cost excludes judge calls, which are tracked separately so a scoring model never flatters or penalises an architecture. Every figure on this site is read from results/ at build time.