th-ebe27d: let a host supply the turn's memory (C#, Python, TS, Go)

[brentrager]

The gap

Rust #330 put memory_for_access on StorageAdapter and had the server runner thread the result into the engine's agent options — the seam that lights up Big Smooth's durable auto-recall. The four sibling servers never did.

What makes this worth fixing now: both ends were already built. All five engine cores implement Memory and already recall relevant entries into context. The only thing missing was the wire between them — so no matter what store a deployment had, every turn on these servers ran without auto-recall. A fully-implemented capability, unreachable.

What changed

Each server now takes a MemoryProvider (IMemoryProvider in C#) with one method — memoryForAccess(access) — resolved per turn and handed to the engine as AgentOptions.memory:

	seam	how a host installs it
C#	IMemoryProvider	DI — services.GetService<IMemoryProvider>()
Python	MemoryProvider	ServerState.memory_provider
TypeScript	MemoryProvider	serve({ memoryProvider })
Go	MemoryProvider	WithMemoryProvider(...)

access is threaded exactly as it is for knowledge, so a multi-tenant host can bind memory to the requester's org/user. Single-tenant hosts — Big Smooth's daemon, the reason this seam exists — ignore it, so each language also ships a StaticMemoryProvider over one store.

Go and Python attach the store post-construction (alongside hooks) rather than growing an 11- and 15-parameter constructor further. That is the pattern those files already use, and for this exact reason.

Opting out is the default, and it is tested

No provider — or a provider that returns nothing for this caller — leaves the turn byte-for-byte what it was. That is a test in every language, not a claim. Five per language, named after their Rust counterparts in rust/smooth-operator-server/tests/injection_seams.rs:

1. no provider ⇒ nothing injected
2. provider declines this caller ⇒ nothing injected (the seam must not fabricate a store just because one was installed)
3. attached memory ⇒ recalled into the turn
4. unrelated message ⇒ recalls nothing (relevance-gated by the engine, not a blanket dump of every stored memory into every turn)
5. the provider actually receives the caller's access

All four mutation-checked — dropping the single line that hands memory to the engine fails them, so they are not vacuous.

Verification

	result
C#	412 passed
Python	389 passed, 21 skipped; ruff clean
TypeScript	43 files passed; tsc clean
Go	full go/server suite green

Two things worth knowing

• The recall block's header text is deliberately not asserted. The five cores inject three different strings for it — Rust [Recalled memories], Python/Go/TS Relevant memory (things you remember about this user/context):, C# Relevant memory: — filed as th-ffaeae. The tests assert the recalled content reaches the model, which is the behavior the seam exists for. A conformance scenario for auto-recall is blocked on unifying that string.
• The bundled lexical scorer counts raw token overlap with no stopword filter. A single shared "the" is enough to score a hit — my first draft of test 4 failed for exactly that reason. Worth knowing before trusting recall precision in production; it is documented as test-grade in the core.

Notes

• No wire-protocol change.
• Changeset names the lockstep anchor @smooai/smooth-operator (per the anchor guard: fail a PR that changes a lockstep-stamped tree without naming the anchor #356 guard).
• With this and th-ebe27d: resolve send_message.skill in the Python and Go servers #560, two of the three th-ebe27d seams are done. The MCP client (th-2b6bf1: MCP client — configured MCP servers surface as engine tools #340) is the remaining one, and unlike this it is genuinely engine-layer — it lives in smooth-operator-core and needs a release per language.

🤖 Generated with Claude Code

[changeset-bot]

🦋 Changeset detected

Latest commit: c834fb3

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@smooai/smooth-operator	Patch
@smooai/smooth-operator-web-chat-example	Patch

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