ADR-0005 — OAuth subscription accounts only
Context and Problem Statement
cam exists to measure and swap accounts by quota. The usage endpoint GET /api/oauth/usage answers only for OAuth subscription credentials; API keys are rejected 401.
Decision Drivers
- Every feature (usage display, headroom ranking, threshold auto-switching) presumes measurable quota windows.
- Supporting API-key accounts would add an account kind that cannot be measured: a second-class citizen in every strategy.
Considered Options
- OAuth subscription accounts only
- Also accept API keys / setup tokens
Decision Outcome
Chosen option: "OAuth subscription accounts only", because every feature presumes measurable quota windows.
Only OAuth subscription accounts are registered. add goes through the claude OAuth login (ADR-0004); there is no API-key path.
Consequences
API-key and setup-token accounts are an explicit v1 non-goal. If Anthropic ever exposes usage for other credential types, this ADR is the thing to revisit; the gating fact is measurability, not the credential format.
Pros and Cons of the Options
| Option | Pro | Con |
|---|---|---|
| OAuth subscription accounts only | One credential shape; every account is measurable | Users of API-key billing are out of scope |
| Also accept API keys / setup tokens | Wider coverage | Unmeasurable accounts break the strategy contract; more auth surface to secure |