Build · Module
Developer Platform
SDK, CLI, sandboxes and a publishing pipeline for partners and developers
The Developer Platform gives partners and professional developers an SDK, CLI, sandbox tenants and contract tests to build Packs, connectors and Action handlers. It is offered as a partner programme with marketplace publishing in W3.
What it does
The Developer Platform is planned for W3 (Year 2 H2, alongside Marketplace GA) and is offered as a partner programme. It is how ISVs, implementation partners and Industry Edition partners build vertical Packs on One3.
Tools
A developer portal documents the Pack schema, Action spec and an API reference generated from OpenAPI, with guides, a changelog and a kernel version support matrix. Sandbox tenants are isolated with synthetic, resettable seed data and no production data. The CLI covers init, validate, generate, test, deploy to sandbox, package and submit. The TypeScript SDK includes a generated API client, an Action handler SDK, event subscription helpers and test utilities. A manifest validator and AI assistant checks risk tiers, reversibility, permissions and translations and suggests fixes.
Building safely
PackRepo links GitHub or GitLab repositories with CI templates for validation and contract tests and signed build artefacts. Contract tests run against supported kernel versions and must pass to deploy or publish. DeveloperApp OAuth clients show tenants a consent screen with scopes, Actions and reversibility classes. SDK keys are scoped and rotatable with usage dashboards. Webhooks and event subscriptions use signed CloudEvents with retries, dead-letter queue and replay. Custom Action handlers run in TypeScript in a sandbox with CPU, memory and time limits and allowlisted egress, called only through the Action Bus. Custom connectors use a connector SDK with conformance tests.
Publishing
Private deployments go to named tenants with a permission diff and tenant admin approval. The Marketplace submission pipeline signs packages and runs malware, secret, dependency, licence and prompt-injection scans, a permission diff and a compatibility report before human review. Partner tiers, revenue share statements and payouts (tax handling to verify with a CA), aggregated Pack telemetry with no tenant business data, MCP templates and a required security contact with force-disable by One3 complete the programme. A Builder MCP server lets coding assistants validate and test drafts on a Pack repository.
Features
What Developer Platform includes
Developer portal and docs
Pack schema, Action spec, generated API reference, guides, changelog and kernel support matrix.
Developer accounts and verification
Individual or organisation accounts with identity verification before publishing (verify).
Sandbox tenants
Isolated developer tenants with synthetic, resettable data and no production data.
CLI
init, validate, generate, test, deploy to sandbox, package and submit.
TypeScript SDK
API client, Action handler SDK, event helpers and test utilities.
Manifest validator and AI assistant
Checks risk tiers, reversibility, permissions and i18n and explains errors.
PackRepo and contract tests
GitHub or GitLab links, CI templates, signed artefacts and tests against supported kernel versions.
OAuth apps and SDK keys
Tenant consent screens showing scopes and Actions, plus scoped, rotatable keys with dashboards.
Webhooks and event subscriptions
Signed CloudEvents with retries, dead-letter queue and replay.
Custom Action handlers
Sandboxed TypeScript handlers with resource limits and allowlisted egress, called via the Action Bus.
Custom connectors
Connector SDK with required reliability fields and conformance tests.
Private deployments and Marketplace pipeline
Named-tenant installs with permission diff, and signed submissions with security scans and review.
Partner tiers and revenue share
Registered and certified tiers, statements and payouts (verify tax handling).
Pack telemetry and security contact
Aggregated installs and error rates with no tenant data, plus required security contact and force-disable.
Workflow
Build to marketplace listing
- 1
Developer creates a sandbox and scaffolds a Pack with the CLI
- 2
Manifest is validated and contract tests pass in CI
- 3
Pack is deployed to the sandbox and tested
- 4
Submission is signed and scanned for malware, secrets, licences and prompt injection
- 5
Human review approves the listing
AI
AI skills and Digital Employees
Manifest validation assistant
Explains errors and suggests fixes in Pack manifests.
Builder MCP tools
Validate, draft, test and diff from coding assistants working on a Pack repository.
Digital Employees that use this module
They act through the same governed Actions as people; risky steps wait for approval.
Frequently asked questions
When will the Developer Platform open?
It is planned for W3, Year 2 H2, alongside Marketplace GA.
Can partner code access tenant data freely?
No. Custom handlers run in a sandbox with resource limits and allowlisted egress and are called only through the Action Bus. Tenants see scopes and Actions before consenting.
What do developers see about tenant usage?
Aggregated installs, versions, error rates and performance only, with no tenant business data.
See Developer Platform in your workflow
Tell us about your team and the outcomes you want. We will walk you through the apps, the Digital Employees and the plan for your industry.