* fix(#2598): declare OpenCode subagent dispatch synchronous, not background
capabilities/opencode/capability.json advertised dispatch.background: true and
dispatch.backgroundDispatch: true. negotiateHostCapabilities and every
degradationFor / shouldFlattenDispatch consumer trusts these per-field values, so
declaring a capability the host lacks OVERSTATES it — the opposite of the
fail-closed posture the negotiation is built for.
The issue's own citations needed checking before acting: the host-integration
matrix (ADR-1239's designated deployment source-of-truth) documented `true` with
NEWER evidence than the issue cited, and explicitly marked the issue's
sst/opencode#5887 reference as a stale snapshot superseded by #2087. git log
confirms #2087 deliberately flipped these from false to true, citing OpenCode
v1.15.0/v1.17 as "background subagents enabled by default in all modes". Applying
the issue as filed would, on that evidence, have REGRESSED a deliberate update.
So the claim was verified against current upstream rather than either document.
`packages/opencode/src/effect/runtime-flags.ts` on `dev` today reads:
experimentalBackgroundSubagents: enabledByExperimental("OPENCODE_EXPERIMENTAL_BACKGROUND_SUBAGENTS")
`enabledByExperimental` falls back to the `experimental` flag and `bool()`
defaults to false — the parameter is hidden from the model unless an operator
opts in by env var. Upstream #29638 is still OPEN and confirms the session loop
`tasks.pop()`s one subtask at a time. #2087's "default-on in all modes" reading
does not hold against current dev.
The issue's CONCLUSION is therefore right even though part of its evidence was
superseded: concurrent dispatch cannot be relied on, so both fields are false.
The matrix rows are corrected with the verified citation rather than reverted to
the old #5887 quote, so the record shows why the value is false TODAY rather than
re-asserting evidence that was legitimately superseded. Neighbouring sub-fields
are untouched and pinned by test: namedDispatch, subagentToolkit, and
isolation:'orchestrator-worktree' (which works via `opencode run --dir` at the OS
process level and is unaffected — #2584 does not depend on this value either way).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015TCwhbMuY37DzRMCfzTABJ
* fix(#2598): re-pin the dispatch contract tests to synchronous OpenCode dispatch
gsd-test on the descriptor change came back FAILED (5 unique, both node
versions). The failures were not incidental — they were deliberate contract-pin
tests encoding #2087's decision, one named literally "background UPGRADE":
tests/host-integration-descriptors.test.cjs
- EXPECTED_FLATTEN[opencode] === false (background-eligible)
- the derived background-eligible set pin
tests/opencode-imperative-reference.test.cjs
- "descriptor declares background dispatch true/true (v1.15/v1.17 upgrade)"
- "background UPGRADE changes shouldFlattenDispatch: false now"
So this is a recorded decision being reversed, not drift being corrected, and it
is reversed on evidence: current upstream `dev` gates the capability behind
OPENCODE_EXPERIMENTAL_BACKGROUND_SUBAGENTS (default false) and upstream #29638
(OPEN) confirms the session loop still handles one subtask at a time. The issue
is filed by the maintainer and explicitly directs "update golden-parity /
validator fixtures as needed", which sanctions re-pinning.
Behavioral consequence, verified: shouldFlattenDispatch(opencode) now returns
TRUE, so GSD serializes opencode dispatch instead of trusting concurrency it
cannot get. That is the correct fail-closed direction and is safe today — no
shipped GSD flow drives OpenCode background waves (per the issue), and
isolation:'orchestrator-worktree' is unaffected because it works at the OS
process level via `opencode run --dir`, not via the native subagent.
Each re-pinned test now asserts the retracted contract in the opposite
direction — feeding the #2087 axes back in must still yield "would not flatten" —
so a silent re-flip of either field is caught rather than merely un-asserted.
lint:ci exit 0.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015TCwhbMuY37DzRMCfzTABJ
* chore(#2598): backfill changeset pr number (#2682)
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
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