Extension System

Broader, capability-gated host contributions — calm rooms in the same dojo.

Parent: OVERVIEW.md · Skills: PLUGIN_ARCHITECTURE.md · SDK: packages/extension-sdk

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Purpose

Horizon 3–4 needs more than agent skills: new discovery sources, send channels, optional UI panels (interview readiness, narrative studio), and export tools. The extension system is the umbrella for host-level contribution points.

Extensions deepen the Career OS without forking into unrelated products or cloud upsells.

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SDK surface

Implementation: packages/extension-sdk.

import { createExtensionManager, defineExtension } from "@jobjitsu/extension-sdk";

• Type-safe contribution map · lifecycle hooks · scoped DI · optional Extension.* events
• Manager starts empty — no official extensions are bundled
• Depends on shared / logger / events / core only (no cycle with sdk or plugin-sdk)

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Contribution points

Point	Examples	Guardrail
discovery.source	Board adapters, RSS, local CSV	Fit curation; not infinite social feed
send.channel	Board submit, mailto, file export	Always through Send policy + approval
agent.skill	(delegates to plugin host)	Preparative only
ui.panel	Optional module views	One job per view; brand tokens
ui.status	Extra trust indicators	Cannot replace Agent · On-device honesty
timeline.exporter	Portability dumps	User-triggered
scheduler.jobType	Custom local jobs	Quiet hours respected

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Manifest (conceptual)

id: official.discovery.example-board
name: Example board source
version: 1.0.0
contributes:
  - type: discovery.source
    id: example-board
permissions:
  - network.fetch: ["https://example.board/*"]
  - discovery.write_candidates
ui:
  settings: ./settings-fragment   # optional

Enablement is per-extension (or per-contribution) with visible permissions.

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Capability & permission lattice

                    ┌────────────────────┐
                    │   User enablement  │
                    └─────────┬──────────┘
                              ▼
                    ┌────────────────────┐
                    │ Capability grant   │
                    │ (host token)       │
                    └─────────┬──────────┘
                              ▼
              ┌───────────────┴───────────────┐
              ▼                               ▼
     Contribution runs                 Denied APIs throw
     within declared scope             (no ambient fs/net)

Send channels receive a host-provided send façade that:

1. Checks preferences (approval-before-send).
2. Requires Queue approval when policy says so.
3. Emits Send.* and Privacy.EgressRecorded.
4. Returns honest success | failed | unknown.

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Loading & isolation

• Extensions load in the host process (or dedicated worker), never with unconstrained renderer privileges.
• UI fragments render in sandboxed webviews/panels with a narrow bridge.
• Crash of an extension must not corrupt identity storage; Agent pause remains available.

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First-party vs third-party

	First-party	Third-party
Shipped in	plugins/ / curated registry	User install path
Default	May ship enabled only if zero sensitive perms	Always default off
Update	App release	Manual / explicit

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UI contribution rules

• Use shared ui tokens (Midnight Ink, Electric Teal, Inter).
• Sentence-case copy; voice from brand docs.
• No streak widgets, guilt banners, or employer-facing dashboards.
• Empty states invite; they do not plead.

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Lifecycle

discover → inspect manifest → user enables → grant capabilities
  → register contributions → run → user disables → revoke → unload

Timeline may record enable/disable when it affects trust posture.

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Extension vs product module

A product module (Features doc) may be implemented as core packages first. When community or optional depth is needed, the same UX can be backed by an official extension. Architecture prefers core for spine, extensions for optional breadth — still one OS feel.

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Forbidden extensions

• Anything that stores résumés in a third-party cloud by default.
• Employer surveillance / candidate ranking for hiring funnels.
• Autopilot send without sovereignty.
• Ad injection or career-data resale.