The Series adapter's Core seam does not exist — 2026-08-27

Evidence boundary

This is a static reachability finding, not a campaign. Nothing here was measured on a validator or in ProgramTest. It is a claim about what the code in this tree can and cannot do, and every step below names the exact file and line so it can be rechecked or refuted. Where it says a route "cannot succeed", that is an argument over the dispatch structure, not an observation of a failing transaction — no transaction has ever reached these routes at all, which is precisely the problem.

Headline

Every route of programs/dclutch-series-sbf is unreachable-to-success against the programs/dclutch-core-sbf in this tree. All three routes end in a Core CPI that Core's dispatch refuses by construction, so the best outcome any of them can reach is SeriesSbfError::RoleCpi. This is not a missing test and not a missing tier. It is a seam that was never joined, on a Series representation the rest of the tree has since moved off.

The census records four series/* routes as NEVER-EXECUTED with the reason "no tier deploys it". That reason is true but it understates the situation: a tier that deployed it would still not execute a single route.

The argument

1. The adapter always calls Core, on every route

programs/dclutch-series-sbf/src/lib.rs:110-137 dispatches on instruction length to exactly three routes: bootstrap (BOOTSTRAP_BYTES_V1), fund_ticket (TICKET_BYTES), and execute_transition (REQUEST_BYTES).

• bootstrap ends at invoke_core(..., SeriesCoreActionV1::Prepare, ...) (lib.rs:217-226).
• fund_ticket ends at invoke_core(..., SeriesCoreActionV1::Prepare, ...) (lib.rs:266-275).
• execute_transition calls stage_prepared (lib.rs:288), which selects Consume, Expire, or Close and calls invoke_core (lib.rs:355-386).

There is no route that returns Ok without invoke_core returning Ok.

2. The CPI carries a bare request with no receipt tail

invoke_core builds the child instruction with data: prepared.request_bytes.to_vec() (lib.rs:844), where request_bytes is [u8; SERIES_CORE_REQUEST_BYTES_V1] produced by request.encode() (lib.rs:774). SERIES_CORE_REQUEST_BYTES_V1 = 336 (crates/dclutch-market-core-codec/src/generated_physical.rs:5). The instruction data is therefore exactly 336 bytes, always.

3. Core's dispatch requires a tail that is not there

programs/dclutch-core-sbf/src/lib.rs:176-232 handles SERIES_CORE_REQUEST_MAGIC_V1 in two arms, each gated on a trailing receipt:

Each arm computes instruction_data.len().checked_sub(TAIL) and then .filter(|start| *start >= SERIES_CORE_REQUEST_BYTES_V1). At len == 336:

• 336.checked_sub(1008) is None — the Claims arm is skipped.
• 336.checked_sub(320) is Some(16), and 16 >= 336 is false — the Custody arm is skipped.

Control reaches return Err(CoreSbfError::Instruction.into()) at core-sbf/src/lib.rs:232. The adapter maps any CPI failure to SeriesSbfError::RoleCpi (series-sbf/src/lib.rs:855).

4. Even with a tail, three of the four actions have no handler

SeriesCoreActionV1 has four variants — Prepare = 0, Consume = 1, Expire = 2, Close = 3 (crates/dclutch-market-core-codec/src/physical.rs:591-600). Both Core arms refuse anything but Consume:

• programs/dclutch-core-sbf/src/series_open.rs:253 — if request.action() != SeriesCoreActionV1::Consume { ... }
• programs/dclutch-core-sbf/src/series_consume.rs:296 — identical.

Grepping programs/dclutch-core-sbf/src/ for SeriesCoreActionV1::Prepare, ::Expire, or ::Close returns nothing. So the two routes that send Prepare (bootstrap, fund_ticket) and the two transition actions Expire and Close have no counterpart in Core at all, tail or no tail.

Why this happened: two Series representations, one seam

dclutch-series-sbf is the only consumer of crates/dclutch-series-codec in the tree. Everything else that speaks Series speaks crates/dclutch-series-v3-kernel:

Core's live Series seam is the v3 one, reached through dclutch_series_v3_kernel composition (crates/dclutch-series-v3-kernel/src/ composition.rs:50, src/lib.rs:941) and driven today by Trading's src/series/ and by programs/dclutch-core-sbf/tests/found_program_test.rs, which stands up a real-ELF series_consume campaign with a caller program at programs/dclutch-core-sbf/test-programs/series-consume-caller/.

dclutch-series-sbf is a parallel authority path for the same concept, on the older representation, with a Core seam that was never built on the Core side. Its 12 unit tests all pass; they exercise the adapter's own frame, identity, and codec checks, none of which is the seam.

What this needs: a decision, not a test

AGENTS.md: "Do not preserve parallel legacy/current authority paths. When a successor is accepted, delete the superseded path in the same convergence cycle." The successor was accepted — Core, Trading, the Shadow accelerator and the operator are all on v3. Two admissible outcomes, and this lane cannot pick between them alone because the second is a protocol decision:

1. Delete programs/dclutch-series-sbf and crates/dclutch-series-codec, remove dclutch-series-sbf from the census TARGETS, and drop the four series/* blocking entries. This is what the "delete the superseded path" rule says on its face, and nothing in the tree depends on either crate.
2. Re-seam it onto v3: give Core handlers for Prepare, Expire, and Close, and give the adapter the receipt tail for Consume. This is a real protocol expansion — Prepare in particular is a prepayment step Core does not currently have a concept of — and would need its own ADR.

Doing neither is the only outcome that is definitely wrong, because today the census counts four routes and twelve refusal codes as merely un-driven, when in fact no campaign anyone writes can drive them.

What is NOT claimed here

• Not claimed: that dclutch-series-sbf is wrong, or that its unit tests are wrong. They test what they test and they pass.
• Not claimed: that the v3 Series path is complete. core/series_open and core/series_permit_expiry are still NEVER-EXECUTED, and the joined founding composition they sit inside is another lane's.
• Not claimed: any measurement. No transaction in this document was executed.