1  # ADR-0001 — Use Gleam OTP Actors for Server Sessions
 2  
 3  Date: 2026-05-07
 4  
 5  Status: Proposed
 6  
 7  ## Context
 8  
 9  Lightspeed needs per-session state ownership, ordered message processing, crash isolation, and supervision.
10  
11  ## Decision
12  
13  Model a live session as a typed actor on the BEAM. The first implementation should use Gleam OTP actors rather than raw processes unless benchmarks or API constraints show that raw processes are required.
14  
15  ## Consequences
16  
17  Easier:
18  
19  - session isolation
20  - typed messages
21  - supervision
22  - testing actor boundaries
23  
24  Harder:
25  
26  - direct portability to JavaScript target
27  - distributed session migration
28  - keeping the core package free of BEAM-only assumptions
29  
30  ## Alternatives considered
31  
32  - one process per transport connection with ad hoc state
33  - stateless request/reply model
34  - external process manager