API V2 Routes

Adding /api/v2 routes for a CRUDable resource

/api/v2 is served by Huma v2 mounted on an Echo group via Huma's upstream humaecho adapter plus the pkg/modules/humabridge glue (echo-context stashing, group-prefix rewriting for AutoPatch). Unlike v1's generic WebHandler, each operation is a typed Huma handler registered explicitly. The handlers are thin: they pull auth off the context, call the same pkg/web/handler.Do* functions v1 uses, and translate domain errors into RFC 9457 responses.

Reference implementation: pkg/routes/api/v2/labels.go is the canonical example — copy its shape. Shared envelopes live in pkg/routes/api/v2/types.go; the auth/error bridge in pkg/routes/api/v2/errors.go; config in pkg/routes/api/v2/huma.go.

Prerequisite: the model must be CRUDable

v2 handlers call handler.DoReadAll/DoReadOne/DoCreate/DoUpdate/DoDelete, which invoke the model's Can* methods. If the model isn't already a working v1 resource, do the model work first — invoke the crudable skill. Permissions are enforced at the model level; never re-check them in a v2 handler.

Every exposed model field needs a doc: tag. v2's schema is reflected from struct tags at runtime; Huma cannot read the Go doc comments swaggo uses for v1. A field without doc:"..." ships with no description in the spec. Add the tag alongside the existing comment (keep both — swaggo still reads the comment for v1, and they should stay in sync):

// The title of the label. You'll see this one on tasks associated with it.
Title string `json:"title" minLength:"1" maxLength:"250" doc:"The title of the label. You'll see this one on tasks associated with it."`

These model edits are safe for v1 — swaggo, XORM, and govalidator all ignore the doc tag. (Huma does read validation tags like minLength/maxLength/enum/format, so those carry over without a doc tag.) As with operations, a doc tag earns its place when it says something the field name and type don't: a format hint ("hex, 6 chars"), a read-only note ("set by the server; ignored on write"), units, or allowed values. "The label description." on a Description field is filler. See pkg/models/label.go for the reference.

Mark server-controlled fields readOnly:"true". Because the same model struct is the request body and the response, fields the client can never set — id, created, updated, created_by, and similar server-derived relations/IDs — should carry readOnly:"true". Huma reflects this into the OpenAPI schema (readOnly: true), so docs and client generators present the field as response-only and drop it from request examples:

ID        int64      `json:"id" readOnly:"true" doc:"The unique, numeric id of this label."`
CreatedBy *user.User `xorm:"-" json:"created_by" readOnly:"true" doc:"The user who created this label."`
Created   time.Time  `xorm:"created not null" json:"created" readOnly:"true" doc:"A timestamp when this label was created. You cannot change this value."`

The tag is documentation only — Huma does not reject these fields if a client sends them on create/update. Actual immutability still comes from the model layer (XORM-managed created/updated, created_by being xorm:"-" and set server-side). It's also harmless on v1 (swaggo/XORM/govalidator ignore it). Don't bother tagging fields that are already json:"-" (absent from the schema entirely), and skip it on response-only structs like the error model — there it's cosmetic since they never appear as a request body. See pkg/models/label.go and pkg/user/user.go.

Steps

1. Create pkg/routes/api/v2/<resource>.go

Define the list-response body, a Register<Resource>Routes(api huma.API) function, and one handler per operation. Mirror labels.go exactly:

// Element type matches what models.<Model>.ReadAll returns; extra fields
// tagged json:"-" keep the wire shape identical to the plain model.
type fooListBody struct {
	Body Paginated[*models.Foo]
}

func RegisterFooRoutes(api huma.API) {
	tags := []string{"foos"}

	Register(api, huma.Operation{
		OperationID: "foos-list",
		Summary:     "List foos",
		Description: "Returns the foos the authenticated user has access to, paginated.",
		Method:      http.MethodGet, Path: "/foos", Tags: tags,
	}, foosList)
	Register(api, huma.Operation{OperationID: "foos-read", Summary: "Get a foo", Description: "...", Method: http.MethodGet, Path: "/foos/{id}", Tags: tags}, foosRead)
	Register(api, huma.Operation{OperationID: "foos-create", Summary: "Create a foo", Description: "...", Method: http.MethodPost, Path: "/foos", Tags: tags}, foosCreate)
	Register(api, huma.Operation{OperationID: "foos-update", Summary: "Update a foo", Description: "...", Method: http.MethodPut, Path: "/foos/{id}", Tags: tags}, foosUpdate)
	Register(api, huma.Operation{OperationID: "foos-delete", Summary: "Delete a foo", Description: "...", Method: http.MethodDelete, Path: "/foos/{id}", Tags: tags}, foosDelete)
}

Use the package's Register wrapper, not huma.Register directly — it sets DefaultStatus from the verb (POST → 201, DELETE → 204). Don't spell out DefaultStatus unless you need a non-default code. Don't set Security: per operation — it's applied globally in NewAPI.

Every operation needs a Summary and Description. v2's OpenAPI spec is generated from these Operation fields at runtime — unlike v1's swaggo, Huma cannot read Go doc comments, so anything you don't put in the Operation (or in a doc: tag, see below) is simply absent from the spec and the docs UI. An operation without them ships undocumented.

Make the description document the non-obvious — don't restate the verb+noun. "Deletes a label" adds nothing over DELETE /labels/{id}. Spend the description on what a consumer can't infer from the method/path/schema: permission scope ("only the owner may delete it"; "returns only labels you can see, not a global list"), full-replace vs partial (PUT replaces, PATCH merges), read-only/conditional behavior (ETag → If-None-Match → 304), side effects (create sets ownership), non-obvious status codes. If the honest description is just the verb+noun, a short summary alone is fine — don't pad. See labels.go for the calibration.

2. Write the handlers

Every handler: pull auth with authFromCtx(ctx), call the matching handler.Do*, wrap returned errors in translateDomainError. Use the shared envelopes from types.go (singleBody, singleReadBody, emptyBody, ListParams, Paginated/NewPaginated).

• List takes *ListParams (gives you page/per_page/q for free, already doc:-tagged in types.go — no need to re-document them) and returns *fooListBody. You must type-assert the DoReadAll result to the concrete slice — result is any, and a blind cast or a generic wrapper silently serialises [] (the "generic-any silent-empty trap"). Return a hard error on mismatch:

  items, ok := result.([]*models.Foo)
  if !ok {
      return nil, fmt.Errorf("foos.ReadAll returned unexpected type %T", result)
  }
  return &fooListBody{Body: NewPaginated(items, total, in.Page, in.PerPage)}, nil
  

• Extra query params go directly on the handler's input struct — not in a shared/embedded helper. Beyond ListParams, if an operation needs its own query params (expand, order_by, include_public, …), declare each as a direct field with its own query:"…" tag on that operation's input struct, then bind it onto the model. A shared or embedded struct of query fields silently fails to bind under Huma when combined with other query params/embeds — the field arrives empty (hit while implementing Project's expand). Flatten them into the input struct.
• Read embeds conditional.Params in its input. To surface the caller's permission, define a small per-resource response struct that embeds the model by value and adds the permission: type fooReadBody struct { models.Foo; MaxPermission models.Permission \json:"max_permission" readOnly:"true" doc:"..."` }. Go and Huma both promote the embedded model's fields, so the wire shape is flat (model fields + max_permission) with no custom marshaler and nothing added to the shared model struct. Capture DoReadOne's returned max permission (it is 0/1/2on success — **never discard it as_**), build the body, and return conditionalReadResponse(&in.Params, body, foo.Updated, maxPermission). The shared helper (in types.go) folds the permission into the ETag (so a share/role change invalidates the cache), applies the conditional precondition (304/412), and returns *singleReadBody[fooReadBody]. See labels.go/project_views.go. (A generic struct{ T; ... }` is impossible — Go forbids embedding a type parameter — so the per-resource struct is the price of a flat shape without a marshaler.)
• Create / Update return *singleBody[Model] and set the model's ID from the path (URL wins over body). Update's request body must be the same fooReadBody the read returns, not the bare model — AutoPatch's GET→PUT round trip echoes the read body (max_permission included) into the PUT, and because max_permission is a declared readOnly property of fooReadBody's schema, Huma accepts and ignores it on write rather than rejecting it. Take &in.Body.Foo (the embedded model — value-embedded, so never nil) and ignore the embedded MaxPermission. Create stays a bare Body Model (AutoPatch only round-trips into PUT).
• Delete returns *emptyBody.

3. Self-register the resource

Resources self-register — you do not edit pkg/routes/routes.go. In your resource file, add an init() that hands your registrar to AddRouteRegistrar:

func init() { AddRouteRegistrar(RegisterFooRoutes) }

func RegisterFooRoutes(api huma.API) { ... }

registerAPIRoutesV2 in routes.go calls apiv2.RegisterAll(api), which runs every registered registrar (in init/filename order — route order is irrelevant) and then EnableAutoPatch. New resources touch zero shared lines, so they never conflict on routes.go.

Notes:

• Give each registrar a DISTINCT name. They share package apiv2, so two resources both exporting RegisterAvatarRoutes collide and won't compile — that actually happened and the upload one had to be renamed (RegisterAvatarRoutes for the binary endpoint vs RegisterAvatarUploadRoutes for the upload). Name yours after the specific resource.
• Config-gated resources check the flag inside the registrar. RegisterAll runs at request-router-setup time, after config is loaded, so a RegisterFooRoutes may early-return (or skip individual Register calls) based on config.FooEnabled.GetBool(). Don't try to gate at init() time — config isn't loaded yet.
• AutoPatch is automatic. RegisterAll calls EnableAutoPatch after all registrars — don't call it yourself, and don't register a manual PATCH (see "What's automatic").

REST verb conventions (v2 inverts v1)

Non-CRUDable / custom routes

Not everything is plain CRUD — bulk operations, custom actions (POST /tasks/{id}/duplicate), sub-resource toggles, RPC-ish endpoints. These still go through Huma and reuse most of the machinery, but two responsibilities move into your handler because there's no handler.Do* doing them for you:

1. Permission enforcement is now yours. This is the one place the "never check permissions in the handler" rule inverts. With no generic Do* to call the model's Can*, the handler must do it explicitly — load the relevant entity and call its permission method, then refuse on denial. Mirror the v1 custom-handler shape (pkg/routes/api/v1/task_attachment.go):

   func tasksDuplicate(ctx context.Context, in *struct{ ID int64 `path:"id"` }) (*singleBody[models.Task], error) {
       a, err := authFromCtx(ctx)
       if err != nil {
           return nil, err
       }
       s := db.NewSession()
       defer s.Close()
   
       t := &models.Task{ID: in.ID}
       can, err := t.CanUpdate(s, a) // or whichever Can* gates this action
       if err != nil {
           _ = s.Rollback()
           return nil, translateDomainError(err)
       }
       if !can {
           return nil, huma.Error403Forbidden("forbidden")
       }
       // ... do the work against s ...
       if err := s.Commit(); err != nil {
           return nil, translateDomainError(err)
       }
       return &singleBody[models.Task]{Body: t}, nil
   }
   

2. Session / transaction management is now yours. The Do* helpers open and commit their own xorm.Session; custom handlers open one with db.NewSession(), defer s.Close(), and Commit/Rollback explicitly for anything that writes.

Otherwise the same rules apply: register with the Register wrapper, pull auth via authFromCtx, route every error through translateDomainError, and reuse the types.go envelopes — or define a small body struct when none fits (don't bend a custom response into singleBody if it's awkward).

Verb choice: pick by semantics, not the CRUD table. Non-idempotent actions are POST. AutoPatch only synthesises PATCH for GET+PUT pairs, so standalone custom routes are never touched.

Token permissions still automatic, but mind the derived name: collectRoutesForAPITokens keys a route off its prefix-stripped path, so POST /api/v2/tasks/{id}/duplicate lands under the tasks group as a duplicate permission. Single-segment custom paths fall into the other group. Name the path so the derived (group, permission) reads sensibly — that string is what users grant tokens against.

What's automatic — do NOT hand-roll

• PATCH — EnableAutoPatch synthesises a JSON-Merge-Patch PATCH for every GET+PUT pair. RegisterAll invokes it after all registrars, so it's automatic — don't call EnableAutoPatch and don't register PATCH yourself.
• API token permissions — collectRoutesForAPITokens walks the Echo router after registration, so your new routes land in the v2 token table automatically under the same (group, permission) keys as their v1 names. PATCH is intentionally not stored; CanDoAPIRoute accepts it as an alias for the stored PUT (see pkg/models/api_routes.go).
• Security schemes — JWTKeyAuth + APITokenAuth are declared globally in NewAPI. For a public endpoint, set Security: []map[string][]string{} on that operation and add its path to unauthenticatedAPIPaths in routes.go.
• Error shape — translateDomainError maps any web.HTTPErrorProcessor (e.g. ErrFooDoesNotExist) onto Huma's status error, producing RFC 9457 application/problem+json. Errors without HTTP semantics become 500.
• OpenAPI spec / Scalar docs / $schema URLs — handled in huma.go. Leave Servers alone (the relative entry must stay at index 0).

Anti-patterns (these get flagged)

• Re-checking permissions in the handler instead of trusting handler.Do* → the model's Can*.
• Blind result.([]*models.Foo) without the ok check, or returning the any straight into the envelope — silent empty lists.
• huma.Register instead of the package Register wrapper (loses the verb-based status).
• Per-operation Security: lines (now global) or registering a manual PATCH (AutoPatch does it).
• Returning a raw model error instead of routing it through translateDomainError → leaks a 500 instead of the right code.
• Unquoted ETag in the response header.
• Operations without Summary/Description, or model fields without doc: tags — they ship undocumented because Huma can't read Go comments.
• Server-controlled fields (id, created, updated, created_by) on a shared input/output model left without readOnly:"true" — the docs then present them as writable request fields.

Tests (mandatory)

Mirror the v1 webtest shape so v2 parity is readable side-by-side. Use the webHandlerTestV2 harness in pkg/webtests/integrations.go — it takes the same urlParams map as v1's webHandlerTest. See pkg/webtests/huma_label_test.go:

• One Test<Resource> covering list/read/create/update/delete, positive + negative (forbidden, nonexistent), mirroring the v1 model test.
• v2-only behaviour (ETag/304, PATCH merge-patch) goes in separate top-level Test<Resource>_* funcs using the humaRequest/humaTokenFor helpers in pkg/webtests/huma_helpers_test.go.
• The RFC 9457 error-body shape is asserted once globally in TestHuma_ErrorShapeIsRFC9457 — don't re-assert the full problem+json shape per resource, just the status code.

Run with mage test:filter Test<Resource> while iterating. Caveat: mage test:filter injects -short, which makes pkg/webtests skip entirely (the suite short-circuits in short mode), so it silently reports success without running your webtest. To actually exercise a single webtest, run it directly: go test -run '<Name>' ./pkg/webtests/. Save output to a file per the project test-output rule.

Related

• crudable skill — the model-layer prerequisite
• pkg/routes/api/v2/labels.go — reference resource
• pkg/routes/api/v2/{types,errors,huma}.go — shared envelopes, bridge, config
• pkg/web/handler/core.go — the Do* functions handlers call