Octo App Builder

OctoMesh App Builder

Build new OctoMesh-powered applications: data model + HTTP API + web app, packaged as one installable blueprint. This skill owns the end-to-end composition recipe; detail work routes to sibling skills.

Routing

Stay in this skill for: designing the app, authoring CK models for it, authoring the blueprint, the HTTP-API pipeline patterns, the Application workload, and the overall sequencing.

Anatomy of an OctoMesh app

blueprint (one InstallBlueprint provisions everything)
├── CK model            — the domain data model (via ckModelDependencies, from a CK catalog)
└── seed-data/entities.yaml
    ├── DataFlow + Pipelines  — the backend: HTTP API + logic on the Mesh Adapter (no service code!)
    └── Application           — the web app: Helm release deployed by the Communication Operator

Tickets/orders/whatever the domain needs are plain runtime entities of the custom CK type — browsable in Studio, queryable via GraphQL, manipulated by pipelines.

A complete worked example lives in the workspace at one-time-ticket/ (read its README.md + CLAUDE.md): secret-redeemable-once app, 3 pipelines, operator-deployed UI. The ZenonDynprop.MainLatest blueprint (meshmakers/blueprint-libraries-build, blueprints/v1/z/...) is the same pattern with two adapters.

Prerequisite checks (run before building)

octo-cli -c AuthStatus                      # valid token, correct environment
octo-cli -c GetAdapters --json              # Mesh Adapter Online? note its rtId

On every communication-enabled tenant the service-managed System.Communication blueprint seeds fixed rtIds your seed will associate to: Pool 670000000000000000000001, Mesh Adapter 670000000000000000000002, dev Helm repo 670000000000000000000003.

For an operator-deployed web app additionally: a cluster with the Communication Operator running (kubectl get pods -n octo-operator-system) — on local dev this is the kind cluster (see octo-devtools for setup).

Build sequence

Work in a dedicated repo folder: ck/ConstructionKit/, blueprint/<Name>/<version>/, app/, test/. The blueprint seed is the single source of truth; anything used for iteration is scratch.

1. CK model → CK catalog

Author a minimal model (one folder, three files — full syntax in references/blueprint-authoring.md §CK model): ckModel.yaml (modelId <Name>-1.0.0, dependency System-[2.0,3.0)), attributes/*.yaml, types/*.yaml (derive from ${System}/Entity-1, reference attributes as ${this}/<AttrId>-1).

# octo-ckc = build output of octo-construction-kit-engine (bin/DebugL/net10.0/octo-ckc.exe), not on PATH
octo-ckc -c Compile -p .\ck\ConstructionKit -o .\ck\out
octo-ckc -c Publish -f .\ck\out\ck-<name>.yaml -r     # → ~/.octo/local-catalog (LocalFileSystemCatalog)

Publishing to the catalog is what lets the blueprint auto-import the model via ckModelDependencies. For pipeline iteration also import it into the tenant now: octo-cli -c ImportCk -f .\ck\out\ck-<name>.yaml -w, then verify the exact attribute IDs with the octo skill's ck_explorer.py preflight <Model>/<Type> --for-import.

2. HTTP-API pipelines (iterate on a scratch dataflow)

Author the API as FromHttpRequest@1 pipelines executed by the Mesh Adapter. The proven patterns — create entity, list without sensitive fields, conditional read-and-update — are in references/http-api-pipelines.md with verbatim YAML. Three rules that are not obvious and break things silently:

1. The HTTP response is the entire final DataContext. End every pipeline with Project@1 + clear: true listing only the response fields — otherwise the raw request body and lookup results (including any secrets) leak into the response.
2. SetPrimitiveValue@1 fails the whole pipeline on a missing source path — guard copies of optional attributes with If@1 on a discriminator field.
3. Result sets are PascalCase ($.lookup.TotalCount, $.lookup.Items[0].Attributes.X); attributeName in CreateUpdateInfo@1 is the CK attribute name as declared.

Iterate with a scratch dataflow: temp rtIds and temp paths (e.g. /myapp-test-*) in a throwaway ImportRt file, ImportRt -f ... -w + DeployDataFlow, curl, fix, re-import with -r. Expect the deploy-rotation quirk (pitfall #2 below) during iteration — it does not affect the final fresh install. When the endpoints behave, copy the pipeline YAML verbatim into the blueprint seed, then undeploy and delete the scratch entities (GraphQL runtime.runtimeEntities.delete, unversioned ckTypeIds).

Reach the adapter for curl tests: in-cluster it serves plain HTTP on :80; from the host use kubectl port-forward -n octo svc/<tenant>-<adapterRtId> 5020:80, routes are http://localhost:5020/{tenantId}{path}.

3. Web app workload (optional)

The platform deploys web apps as System.Communication/Application entities — the operator helm-installs them. The fastest path is fulfilling the existing property-walker chart contract (env PORT + UPSTREAM_URL, probe on GET /, container port 5055): a zero-dependency Node proxy that serves a static SPA at / and forwards /api/* to the tenant-scoped adapter URL. Full recipe, Dockerfile, and the Application entity YAML: references/app-workload.md.

Image handling on local kind (no registry needed):

docker build -t meshmakers/<app>:0.1.0 .\app
docker tag meshmakers/<app>:0.1.0 docker.mm.cloud/meshmakers/<app>:0.1.0
kind load docker-image meshmakers/<app>:0.1.0 docker.mm.cloud/meshmakers/<app>:0.1.0

Tag both names: the communication controller injects image.privateRegistry=docker.mm.cloud at deploy time, so the final image reference gets that prefix. On shared clusters push to docker.mm.cloud instead.

4. Blueprint

Author blueprint/<Name>/<version>/blueprint.yaml + seed-data/entities.yaml — full format in references/blueprint-authoring.md. Key decisions:

• ckModelDependencies: [<Model>-[1.0.0,2.0.0)] — pulls the model from the CK catalog at install; no manual ImportCk for consumers.
• Seed entities use hand-assigned stable 24-hex rtIds (pick a recognizable prefix, e.g. 0771…01) so re-applies are idempotent and entities are identifiable.
• Pipelines associate System/ParentChild-1 → your DataFlow and System.Communication/Executes-1 → Mesh Adapter 670…002.
• The Application associates Manages-1 → Pool 670…001 and HelmRepository-1 → 670…003; hostname template <app>-${octo.tenantId}.{{domain.default}} works on every cluster (127.0.0.1.nip.io on kind).
• Gate with requires: {octo.environment: [dev, test]} if the rollout depends on the operator (staging/prod may not run it).

Install into the local blueprint catalog:

# layout: ~/.octo/local-blueprint-catalog/blueprints/v1/<Name>/<version>/{blueprint.yaml,seed-data/}
Copy-Item ... # copy both files preserving layout
Remove-Item "$HOME\.octo\blueprint-catalog\cache\local-blueprint-catalog-cache.json" -Force
octo-cli -c ListBlueprints     # must now show <Name>-<version>

Deleting the cache file is mandatory — it only rebuilds when missing (pitfall #1).

5. Install + deploy

octo-cli -c InstallBlueprint -b <Name>-<Version>       # -f to force re-apply after seed edits
octo-cli -c DeployDataFlow --identifier <dataflowRtId>
octo-cli -c DeployWorkload -id <applicationRtId>       # only if there is an app

Confirm the install output: Success: true, ApplicationMode: Initial, your model under LoadedCkModels, no warnings. A silent no-op with WasSkipped means the requires: gate did not match the environment.

6. Verify

• Curl matrix against every endpoint: happy path, conditional/error paths, and that no response leaks fields it shouldn't (grep the raw JSON).
• App: pod Running (kubectl get pods -n octo), ingress host answers, then drive the real UI flow in a browser (Playwright) — not just the API.
• On any silent failure read the adapter log first: kubectl logs -n octo deploy/<tenant>-<adapterRtId> — pipeline exceptions, route registrations (Removing pipeline / Registering pipeline), request traces.
• Clean up test entities afterwards so the consumer starts fresh.

Pitfalls (each cost real debugging time)

Design constraints to set expectations early

• Pipeline check-then-update is not atomic — concurrent requests can race. Fine for demos; call it out for production designs.
• No auth on adapter HTTP routes — anyone with the URL can call them.
• Content type is always application/json; the adapter cannot serve HTML. That's exactly why the UI ships as an Application workload instead.

References

• references/blueprint-authoring.md — CK model source syntax, blueprint manifest + seed format, variables, catalogs, lifecycle.
• references/http-api-pipelines.md — verbatim pipeline YAML for create/list/conditional-update APIs, response shaping, debugging.
• references/app-workload.md — Application entity, property-walker chart contract, proxy server pattern, image + deploy loop.