RFC 0172: v2 versioning and release — major negotiation, one origin, every axis dispositioned, one release identity

Summary

v1 has one scalar the wire negotiates on, no way to advertise two majors that COMPATIBILITY §5 nonetheless requires, an engineVersion that is an integer at the root and a string on five carriers, bundleVersion declared four ways (one of them a pattern that rejected its own documented value), and three normative texts presuming a /v2/ path space that the /v1/v1 defect (RFC 0149 §A) already showed is the wrong model. v2 negotiates a major with protocolVersions[], a root preferredVersion, and an OpenWOP-Version request header on a bare origin; v1 keeps its /v1/ path keys through the overlap and v2 operations are unversioned; every axis RFC 0167 §E.1 enumerates gets a disposition here; schemas/v2/ lives under /spec/v2/; the corpus tag is the only release event and every human-surface version is generated with --check.

Motivation

• version-negotiation.md:46–55 (RFC 0165 §A) ships protocolVersions[] and says "v2 defines the negotiation that acts on it". This is that definition.
• rest-endpoints.md:12–14 says breaking changes go to /v2/, servers may serve both side by side, and servers MUST return 400 for unversioned roots; grpc-transport.md:49–50 says v2 would introduce openwop.v2.Engine alongside; api/asyncapi.yaml:42 carries pathname: /v1 on the server — the AsyncAPI mirror of the servers[].url bug RFC 0149 §A fixed in OpenAPI and left in place here, and rest-endpoints.md:15 makes the parity gate enforce the asymmetry.
• The engineVersion split is recorded at version-negotiation.md:57–63 "rather than fixed"; debug-bundle.schema.json:17 declared a bundleVersion pattern that rejected "1" until RFC 0167 corrected it.
• docs/PROTOCOL-STATUS.md §"Artifact Versions" lists two axes; the README banner once advertised three wrong versions on one line (check-advertised-versions.mjs:18–23); no v1.4.0 tag was ever cut; OpenAPI and AsyncAPI info.version are hand-maintained and untracked.
• The A2A lane already solved the header-less default once: a2a-integration.md:349 serves the preferredVersion card when no A2A-Version header is present. v2 applies the same rule to the protocol itself.

Proposal

§A. Major negotiation

§A.1 A v2 host advertises protocolVersions[] (RFC 0165 §A grammar) containing every major.minor it serves and a root preferredVersion that MUST be a member of protocolVersions[]. During the overlap a host serves ["1.<n>", "2.<m>"]; after Phase 5 it serves ["2.<m>"].

§A.2 v1 operations keep their /v1/… path keys unchanged through the overlap. v2 operations are unversioned path keys on a bare origin (servers[].url = https://{host}, RFC 0149 §A): /runs, /runs/{runId}, /.well-known/openwop, … There is no /v2/ path space. rest-endpoints.md §Versioning bullets 1–3 are retracted; the MUST that servers return 400 for unversioned roots is inverted: an unversioned path is the v2 surface.

§A.3 A request on an unversioned path MAY carry OpenWOP-Version: <major> (integer major only; OpenWOP-Version: 2). A host MUST serve the named major when it is in protocolVersions[] and MUST answer 406 Not Acceptable with error code protocol_version_unsupported and a details.protocolVersions[] echo when it is not. When the header is absent, a host MUST serve preferredVersion's major; and while protocolVersions[] contains any 1.x member, preferredVersion MUST be that 1.x — otherwise this rule and RFC 0176 §C.1 (no header ⇒ the v1 document through the overlap) contradict each other, which the reference host found by being unable to satisfy both (Phase 3 P3-E4). A request on a /v1/… path key MUST NOT carry OpenWOP-Version with a value other than 1; a host MUST answer 400 protocol_version_mismatch otherwise.

§A.4 Responses on any path carry OpenWOP-Version: <major>.<minor> naming the contract that produced them. Reporting a version other than the one used is the silent downgrade host-sample-test-seams.md:959 forbids; the dual-stack scenario (§Conformance) falsifies it.

§A.5 Client precedence when both majors are advertised: a v2 client selects the highest major it implements that the host lists; a v1 client (no header, /v1/ paths) is unaffected. minClientVersion (axis 15) becomes a MUST: a host MAY refuse a client below it with 426 Upgrade Required and client_version_unsupported.

§B. Every axis, dispositioned

The table is RFC 0167 §E.1 with the decision made. unify = one type and one grammar in v2 with a codemod; first-class = own schema-enforced grammar and negotiation rule; retire = absorbed into the capability record's {status, since, until?}; delete = removed with a register row.

One grammar covers protocol, envelope kind, and pack axes wherever a version is a major.minor (#1, #2, #11, #15); typeId@<semver> (RFC 0013 UQ2) is a pack axis and C.10 decides pin-or-float; the 2 in typeId@2.0.0 never means OpenWOP-Version: 2.

§C. Where v2 lives

§C.1 spec/v2/core/ and spec/v2/ext/<name>/ (RFC 0167 §B.7); schemas/v2/ with every $id under https://openwop.dev/spec/v2/; published at /spec/v2/ by the site generator iterating spec/v*/ (MAINTAINERS §"Major bump" steps 7–8). schemas/ (flat, v1 $ids) is read-only from the cut. The org question (RFC 0167 UQ1): the same organization and site serve /spec/v2/; the fallback, if the domain moves, is that $id values are immutable identifiers and the site publishes a redirect — recorded as decided, not open.

§C.2 Retractions: rest-endpoints.md §Versioning bullets 1–3; grpc-transport.md:49–50 (C.8 owns the proto's fate; this RFC only retracts the /v1 ↔ /v2 analogy); AsyncAPI servers.production.pathname becomes empty and channel addresses carry their own path, exactly as OpenAPI path keys do. A new corpus check, scripts/check-path-parity.mjs, resolves OpenAPI, AsyncAPI, and (if kept) the proto to absolute paths for the shared event stream and fails on any difference; the canonical OpenAPI contains no seam or test-mode operation (those move to C.1's seams profile).

§C.3 The v2 path manifest (spec/v2/path-manifest.json, generated) carries operations and channels; resolvedPath on a bare origin, exactly one version segment for v1 rows (/v1/…) and none for v2 rows.

§D. One release identity

§D.1 The corpus tag openwop/v2.<minor>.<patch> is the only release event; suite, SDKs, registry, and site derive from it. Every human-surface version (README banner, PROTOCOL-STATUS, OpenAPI/AsyncAPI info.version, conformance/package.json) is generated with --check in the merge gate; the identity check (check-published-suite-identity.mjs) and the advertised-versions check keep their three-outcome discipline; the published tarball digest equals the tree's as a release precondition.

§D.2 PROTOCOL-STATUS gains one row per axis in §B (18 rows), including OpenAPI and AsyncAPI info.version.

Migration table

Persisted-data disposition

Compatibility

breaking (v2). This PR changes no v1.x wire shape. The v1.x additive root preferredVersion is filed as its own small RFC under RFC 0165 §A so both majors can be advertised before the cut; it is optional, MUST be a member of protocolVersions[], and is ignored by v1 consumers.

Conformance

v2 scenarios (suite 2.0.0): dual-stack-negotiation (gated on a host advertising two majors: the same run is created and read through /v1/runs with no header and through /runs with OpenWOP-Version: 2; response headers name the contract used; a header naming an unlisted major yields 406; OpenWOP-Version: 2 on a /v1/ path yields 400), preferred-version-default (unaided: a header-less request on an unversioned path is served as preferredVersion), min-client-version (gated), path-parity (corpus), release-identity (corpus: every human-surface version generated; tarball digest equals the tree).

Falsifiability — one row per normative requirement

RFC 0167 G1 (openwop.gap.0167.1, the header-less default has no v1 precedent) is classified here as witnessable-gated and carried to openwop.gap.0172.1 with the dual-stack scenario as its witness.

Adversarial review

1. A v1 client never sends the header, so the header cannot be the sole selector. Disposition: it is not — the /v1/ path key selects v1 through the overlap; the header selects among unversioned majors and defaults to preferredVersion (§A.2–§A.3; the A2A precedent at a2a-integration.md:349). 2. rest-endpoints.md bullet 3 MUSTs a 400 on unversioned roots — the plan inverts a MUST. Disposition: yes, and only in v2; v1 hosts keep the MUST. Recorded as row C5.6 (behavior) and named in §C.2 as a retraction, not a silent edit. 3. OpenWOP-Version on a response is a new header on the v1 surface if a host emits it on /v1/ paths. Disposition: emitting it on v1 responses is additive (RFC 0165 §C.1 precedent for OpenWOP-); MAY in v1.x, MUST in v2. 4. The engineVersion codemod cannot know whether a string carrier was "the decimal rendering of the root integer." Disposition: the codemod refuses any value that is not ^(0|[1-9][0-9])$; the refusal fixture is committed. 5. typeId@2.0.0 and OpenWOP-Version: 2 share a digit and no meaning. Disposition: stated in §B; C.10 owns the pack axis. 6. The axis table asserted eventLogSchemaVersion v2 value 3, pre-empting C.9. Disposition: retracted; the row keeps the axis first-class and names C.9 as the owner of the value. 7. New error codes: protocol_version_unsupported, protocol_version_mismatch, client_version_unsupported. No collision (interop_version_unsupported is the A2A/MCP boundary code and stays); 426 is already the documented minClientVersion status (capabilities.md:168, version-negotiation.md:265); the flat envelope carries no status field so nothing else changes. Registered in C.4's errors.json. 8. No v1 scenario asserts the 400 on unversioned roots (only path-resolution tests exist), so a dual-stack host does not fail a v1 leg by serving v2 there. 9. The /v1/ path prefix is a path surface, not a discovery shape. Disposition: deprecations.schema.json kind gains path (additive enum growth on a non-wire data schema); the row is re-kinded; the alias-coverage gate treats path as a visible kind. 10. MAINTAINERS step 6 edits spec/v1/auth.md at the cut while RFC 0167 says v1 is read-only from the cut. Disposition: the status-legend pointer is the one permitted v1 edit at the cut; recorded as G2.

Alternatives considered

1. /v2/ path space. Rejected: three texts presume it and all inherit the /v1/v1 composition hazard; two path manifests per major; RFC 0149 §A's bare-origin rule already exists. 2. Two discovery documents (/.well-known/openwop and /.well-known/openwop-v2). Rejected by C.9: one fetch answers both majors. 3. Keep engineVersion split with a reader rule only. Rejected: Axiom 2 (one name per thing) and the codemod is trivial. 4. Do nothing. Rejected: COMPATIBILITY §5 requires a coexistence plan and none exists.

Unresolved questions

1. Whether OpenWOP-Version on requests should accept major.minor (a client pinning a minor) or integer major only. Recommended: integer major only; a minor pin is what minClientVersion and additive rules already cover.

Implementation notes (non-normative)

The v1.x preferredVersion RFC is a one-field additive change (schema optional field + RFC 0165 §A cross-reference) and can land before Phase 3 so both hosts advertise it in their Phase 4 legs. check-path-parity.mjs and the generated info.version land with the v2 tree in Phase 3.

Acceptance criteria

• [x] Draft → Active: RFC text; rows C5.1–C5.9; codemod openwop.codemod.engine-version-unify green on its four legs; register rows; ledger row; adversarial review. (This PR.)
• [ ] Active → Accepted (Phase 3): spec/v2/core/versioning.md; root preferredVersion in schemas/v2/; the three retractions; check-path-parity.mjs; generated info.version; PROTOCOL-STATUS 18 rows; the five scenarios in suite 2.0.0; dual-stack passing on openwop-app from both majors.

References

• RFC 0167 §A, §B.1, §E.1, G1, UQ1; RFC 0149 §A/§C; RFC 0165 §A; RFC 0152/0153 (preferredVersion precedent); RFC 0013 UQ2; RFC 0021 UQ1.
• spec/v1/version-negotiation.md §"Protocol version grammar", §"protocolVersions[]", §"engineVersion axis is split", gaps V1–V5; rest-endpoints.md §Versioning; grpc-transport.md; api/asyncapi.yaml servers; a2a-integration.md:349; docs/PROTOCOL-STATUS.md; MAINTAINERS.md §"Major bump to v2.x"; scripts/check-published-suite-identity.mjs, check-advertised-versions.mjs.