Spike: SaaS source connectors and the determinism/permission boundary

[burakdede]

Parent epic: #8 (post-v0.1 backlog)

Context

§5.2 excludes Google Drive, Notion, Slack, SharePoint, GitHub, and other SaaS synchronization from v0.1, and §24.13 names connector sprawl as the specific risk that would delay the wedge. §22.2 places continuous source connectors in the future paid platform.

Post-v0.1 spike. This issue exists to keep the decision explicit rather than letting connectors creep in.

Spec references

§5.2 Explicitly out of scope, §22.2 Future paid platform, §24.13 Scope-expansion risk, §2.4 product boundary.

Scope

In: a design spike defining how an external source connector would fit the compiler's source model without weakening determinism, incrementality, or the local-first promise.
Out: implementing any connector.

Design notes

• The hard questions are determinism and permissions: remote sources have no stable content hash guarantee without fetching, they can change between plan and build, and they carry per-user access rules that §5.2 explicitly defers.
• Any design must preserve §1.2's invariant: the build remains the source of truth and a remote fetch failure must never corrupt an active build.
• The spike should also decide whether connectors belong in open source at all, given §22.2 positions them as commercial value.

Acceptance criteria

• Document defining a SourceConnector shape that fits §10.1's Source model, covering fetch, caching, content hashing, incremental sync, and failure handling.
• Determinism analysis: how a build stays reproducible when a source can change between plan and build.
• Permission and privacy analysis, including what §5.2 defers (multi-user tenancy, source-permission synchronization) and what would be required to lift that.
• Recommendation on the open-source/commercial boundary for connectors (§22.2).
• Prioritized candidate list with effort estimates, or a recorded decision to defer indefinitely.
• Timeboxed with a written recommendation either way.

Tests / verification

• No implementation; findings reviewed and recorded as an ADR entry.

Dependencies

Blocked by the v0.1 release (#102).

Definition of Done

The connector question has a documented answer, so it can be decided deliberately instead of drifting into scope.