fix: reuse one HTTP connection instead of a client per call

[loks0n]

What

Adapter::call() built a new Utopia\Fetch\Client for every request. Each one leaks its cURL handle and the connection behind it via a closure reference cycle (utopia-php/fetch#22). Stripe now builds requests with utopia-php/psr7's factory and sends them with a utopia-php/client that keeps one handle for the lifetime of the adapter.

Adapter::call() and the METHOD_* constants go with it. A PSR-18 client and a PSR-17 factory already say "build a request, send it", so the indirection bought nothing but a second vocabulary for HTTP — and seven of the nine method constants had no caller. Adapter is back to being the provider contract: no imports, no transport. Stripe owns its client, because the wire format is Stripe's concern and not the contract's.

The client is injected through the constructor and readonly. Pay has no opinion about pooling — a caller that needs one wraps utopia-php/client in its Pool decorator and passes it in. Same for retries, timeouts, or a double under test. The default is a plain connection-reusing cURL client, so the common case needs no wiring.

Net -55 lines.

Why

This is the root cause of task-billing-payments OOM-killing in production (cloud-fra1-prod, ~6×/day, escalating).

The pod idles at ~330 MB of its 512Mi limit. Every day at ~00:20 UTC the newly-due invoice batch runs — ~1000 invoices, several Stripe calls each — and memory climbs to the limit in about four minutes:

00:17  332 MB   loop starts
00:19  374 MB
00:20  450 MB
00:21  533 MB   ← limit is 536 MB. OOMKilled.

It then crash-loops (four container starts in 13 minutes) until the batch clears. The leak is native cURL/TLS memory, so the PHP heap stays flat and memory_limit never trips — nothing is logged, the kernel just kills the process. That is why this looked like a mystery restart with clean logs.

Verification

Both sides of an identical 400-request workload against a local echo server:

	fds	RSS
before (client per call)	+800	+21 MB
after (reused connection)	+0	+48 kB

Request shape is unchanged — same method, path, application/x-www-form-urlencoded body with Stripe's address[city] bracket encoding, same User-Agent:

POST  method=POST uri=/customers ct=application/x-www-form-urlencoded
      body=name=Test%20customer&email=test%40example.com&address%5Bcity%5D=Berlin&address%5Bcountry%5D=DE
      user-agent=Darwin-25.5.0:php-8.5.8

Injection and the default were each checked end to end:

injected client used: user-agent=injected-client/1.0
default  client used: user-agent=Darwin-25.5.0:php-8.5.8

The repo's live-Stripe suite is the real contract check and runs on this PR.

Breaking changes

• PHP 8.5 floor. utopia-php/client requires it, so pay does too. CI matrix drops 8.0–8.3. Cloud is already on 8.5.
• Adapter::call(), Adapter::handleError() and the METHOD_* constants are removed. An out-of-tree adapter that used them should build requests with the PSR-17 factory and send them with its own PSR-18 client, as Stripe::execute() now does.
• Stripe::__construct takes an optional third ?ClientInterface $client.
• multipart/form-data support and the protected flatten() helper are removed. No adapter used either; the new request factory models multipart as typed parts, so a future adapter should build them through that.
• GET params move from the request body to the query string. Stripe accepts both — verified against the live API that a created[gt] filter is honoured either way — so this is a wire-format change, not a behavioural one.

Notes for the reviewer

• composer check (PHPStan) fails on main as well — phpstan 1.9.x-dev chokes on PHP 8.5 itself and reports nothing about src/. Left alone; it is not in CI and fixing it means a PHPStan major bump.
• Redirect following is dropped (the new adapter sets CURLOPT_FOLLOWLOCATION => false). The Stripe API does not redirect.

Follow-up

Cloud builds Pay per DI container in app/init/resources.php, so the HTTP path still gets a fresh client per request. Worth a follow-up to construct it with a shared pooled client once this lands. The CLI tasks — the ones OOMing — hold a single long-lived adapter and are fixed by this alone.

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR replaces per-call Fetch clients with an injectable, adapter-lifetime PSR-18 client to reuse the underlying HTTP connection.

• Moves Stripe request construction to the PSR-7 request factory.
• Moves GET parameters into the query string and form-encodes other request bodies.
• Removes transport helpers and HTTP method constants from the base adapter.
• Raises the PHP requirement and CI floor to PHP 8.5.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains within the eligible follow-up review scope.

Important Files Changed

Filename	Overview
src/Pay/Adapter/Stripe.php	Introduces an injectable persistent HTTP client and moves Stripe request construction, transmission, decoding, and error handling into the Stripe adapter.
src/Pay/Adapter.php	Removes the shared Fetch transport implementation, method constants, multipart flattening helper, and base error handler.
composer.json	Replaces Fetch with PSR HTTP interfaces and Utopia client/PSR-7 packages while raising the PHP floor to 8.5.
composer.lock	Regenerates the dependency lockfile for the new HTTP stack.
.github/workflows/tests.yml	Updates the test matrix to cover PHP 8.5 and nightly.

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