Decompose machine semantic internals

[SandroMaglione]

Summary

• Split the internal model into topology, protocol, configuration, and serialization layers with an inward-only dependency direction.
• Separate pure command collection, process-side command execution, semantic planning, and compiled execution-plan selection.
• Extend the TypeScript-resolved architecture check to reject both runtime and type-only semantic-layer inversions.

Changeset

• Added or updated for a library or package-metadata change
• Not required because this PR does not change src or package.json

Validation

• pnpm check
• Relevant example checks, when examples changed (not applicable; no examples changed)
• Reviewed the automated type-performance report, when the public TypeScript API or inference changed
• Reviewed the automated runtime-performance report, when runtime behavior changed

[github-actions]

Type performance

Measured with TypeScript 6.0.3 and skipLibCheck=true.

Scenario	Base	PR	Difference
Effect only	55	55	0 (0.0%)
Import effect-machine	55	55	0 (0.0%)
Machine.defineStates (3 states)	2,965	2,965	0 (0.0%)
Machine.make (3 states, 2 events)	8,715	8,715	0 (0.0%)
machine.handle (3 states, 2 transitions)	23,492	23,492	0 (0.0%)
machine.handle (depth 8)	117,075	117,075	0 (0.0%)
machine.handle (depth 12)	129,713	129,713	0 (0.0%)
machine.handle (depth 16)	145,055	145,055	0 (0.0%)
machine.handle (depth 24)	183,851	183,851	0 (0.0%)
machine.handle (wide depth 16)	214,189	214,189	0 (0.0%)
machine.handle (parallel/history/choice)	132,667	132,667	0 (0.0%)
machine.handle (4 successive calls)	128,674	128,674	0 (0.0%)
machine exact input/output/error/services	110,584	110,584	0 (0.0%)
execution adapter readiness	127,854	127,854	0 (0.0%)

Marginal instantiations are measured against the matching setup without that API call:

Scenario	Base	PR	Difference
Import effect-machine	0	0	0
Machine.defineStates (3 states)	2,910	2,910	0 (0.0%)
Machine.make (3 states, 2 events)	5,742	5,742	0 (0.0%)
machine.handle (3 states, 2 transitions)	14,777	14,777	0 (0.0%)
machine.handle (depth 8)	109,601	109,601	0 (0.0%)
machine.handle (depth 12)	121,039	121,039	0 (0.0%)
machine.handle (depth 16)	135,181	135,181	0 (0.0%)
machine.handle (depth 24)	171,577	171,577	0 (0.0%)
machine.handle (wide depth 16)	202,224	202,224	0 (0.0%)
machine.handle (parallel/history/choice)	114,331	114,331	0 (0.0%)
machine.handle (4 successive calls)	113,703	113,703	0 (0.0%)
machine exact input/output/error/services	100,670	100,670	0 (0.0%)
execution adapter readiness	102,092	102,092	0 (0.0%)

Check times (informational)

Scenario	Base	PR
Effect only	0.03s	0.03s
Import effect-machine	0.03s	0.03s
Machine.defineStates (3 states)	0.10s	0.10s
Machine.make (3 states, 2 events)	0.14s	0.15s
machine.handle (3 states, 2 transitions)	0.23s	0.21s
machine.handle (depth 8)	0.48s	0.48s
machine.handle (depth 12)	0.53s	0.53s
machine.handle (depth 16)	0.56s	0.55s
machine.handle (depth 24)	0.63s	0.65s
machine.handle (wide depth 16)	0.73s	0.69s
machine.handle (parallel/history/choice)	0.58s	0.60s
machine.handle (4 successive calls)	0.51s	0.53s
machine exact input/output/error/services	0.48s	0.47s
execution adapter readiness	0.57s	0.54s

Type instantiations are the comparison metric. Check time varies with runner load and is informational only.

[github-actions]

Runtime performance

Median of 5 independent benchmark processes on Intel(R) Xeon(R) 6973P-C with Node v24.18.0.

Pull request baseline

Scenario	Effect Machine	XState 5	XState 6 alpha
Plan counter transitions	197,341 transitions/s	184,121 transitions/s	24,472 transitions/s
Drain burst with terminal fence	933,362 increments/s	594,142 increments/s	242,589 increments/s
Drain burst with a change observer	867,240 increments/s	585,029 increments/s	242,831 increments/s
Lookup and send to one child	803,936 increments/s	575,490 increments/s	234,487 increments/s
Start and stop a machine	273,224 machines/s	260,485 machines/s	200,965 machines/s
Start and stop a parent with one child	74,716 families/s	99,621 families/s	66,103 families/s
Plan transitions through a compound state	180,127 transitions/s	—	—
Plan transitions through parallel regions	143,161 transitions/s	—	—
Drain burst through a compound state	924,737 events/s	495,022 events/s	241,374 events/s
Drain burst through two parallel regions	829,452 events/s	389,238 events/s	199,006 events/s
Drain a compound-state burst with a change observer	821,474 events/s	—	—

Effect runtime reference points

Scenario	Effect Machine	Effect runtime primitives
Start and stop a raw generic process	47,592 processes/s	—
Start and stop a raw compiled process	116,836 processes/s	—
Start and interrupt a suspended fiber	—	263,366 fibers/s
Start and stop a queue worker	—	188,964 workers/s
Start and stop an actor shell	—	169,205 actors/s
Start and stop two actor shells	—	99,069 families/s
Update an owner-only mutable snapshot	—	543,183,053 updates/s
Update a synchronized snapshot	—	2,703,287 updates/s
Create, resolve, and await a terminal latch	—	2,658,980 latches/s

Memory profile	Effect Machine	XState 5	XState 6 alpha	Effect runtime primitives
Idle machine	1.5 KiB	3.8 KiB	2.2 KiB	—
Raw generic managed process	12.1 KiB	—	—	—
Raw compiled process	2.6 KiB	—	—	—
Two independent idle machines	2.9 KiB	7.3 KiB	3.9 KiB	—
Idle parent with one child	4.8 KiB	5.5 KiB	4.0 KiB	—
Parent with observed child registry	9.0 KiB	—	—	—
Parent with observed invoked child snapshots	5.0 KiB	—	—	—
Suspended Effect fiber	—	—	—	0.6 KiB
Effect queue with waiting fiber	—	—	—	2.8 KiB
Effect mailbox actor shell	—	—	—	3.2 KiB
Two Effect actor shells	—	—	—	6.8 KiB

Effect Machine change from base

Metric	Base	Base variability	PR	PR variability	Difference
Plan counter transitions	174,679 transitions/s	6.3% MAD	197,341 transitions/s	1.8% MAD	+13.0%
Drain burst with terminal fence	958,170 increments/s	5.5% MAD	933,362 increments/s	3.3% MAD	-2.6%
Drain burst with a change observer	916,389 increments/s	2.3% MAD	867,240 increments/s	4.8% MAD	-5.4%
Lookup and send to one child	802,736 increments/s	2.3% MAD	803,936 increments/s	1.5% MAD	+0.1%
Start and stop a machine	282,486 machines/s	1.9% MAD	273,224 machines/s	3.4% MAD	-3.3%
Start and stop a parent with one child	77,676 families/s	0.8% MAD	74,716 families/s	5.3% MAD	-3.8%
Plan transitions through a compound state	183,289 transitions/s	0.6% MAD	180,127 transitions/s	5.1% MAD	-1.7%
Plan transitions through parallel regions	142,146 transitions/s	0.9% MAD	143,161 transitions/s	4.6% MAD	+0.7%
Drain burst through a compound state	946,085 events/s	1.3% MAD	924,737 events/s	6.2% MAD	-2.3%
Drain burst through two parallel regions	842,681 events/s	1.7% MAD	829,452 events/s	4.9% MAD	-1.6%
Drain a compound-state burst with a change observer	803,879 events/s	1.0% MAD	821,474 events/s	5.9% MAD	+2.2%
Idle machine heap per unit	1.5 KiB	0.2% MAD	1.5 KiB	0.2% MAD	-0.5%
Raw generic managed process heap per unit	12.1 KiB	0.1% MAD	12.1 KiB	0.0% MAD	-0.2%
Raw compiled process heap per unit	2.6 KiB	0.0% MAD	2.6 KiB	0.1% MAD	-0.2%
Two independent idle machines heap per unit	2.9 KiB	0.0% MAD	2.9 KiB	0.0% MAD	-0.2%
Idle parent with one child heap per unit	4.8 KiB	0.0% MAD	4.8 KiB	0.0% MAD	-0.1%
Parent with observed child registry heap per unit	9.0 KiB	0.2% MAD	9.0 KiB	0.2% MAD	-0.1%
Parent with observed invoked child snapshots heap per unit	5.0 KiB	0.2% MAD	5.0 KiB	0.0% MAD	-0.4%

Effect runtime reference change from base

Metric	Base	Base variability	PR	PR variability	Difference
Start and stop a raw generic process	47,313 processes/s	2.6% MAD	47,592 processes/s	0.6% MAD	+0.6%
Start and stop a raw compiled process	117,028 processes/s	0.5% MAD	116,836 processes/s	0.7% MAD	-0.2%
Start and interrupt a suspended fiber	261,028 fibers/s	0.7% MAD	263,366 fibers/s	1.8% MAD	+0.9%
Start and stop a queue worker	188,466 workers/s	0.6% MAD	188,964 workers/s	1.1% MAD	+0.3%
Start and stop an actor shell	174,948 actors/s	1.0% MAD	169,205 actors/s	3.9% MAD	-3.3%
Start and stop two actor shells	108,980 families/s	0.6% MAD	99,069 families/s	2.6% MAD	-9.1%
Update an owner-only mutable snapshot	542,888,166 updates/s	0.1% MAD	543,183,053 updates/s	0.2% MAD	+0.1%
Update a synchronized snapshot	2,706,243 updates/s	1.4% MAD	2,703,287 updates/s	2.5% MAD	-0.1%
Create, resolve, and await a terminal latch	2,618,144 latches/s	0.3% MAD	2,658,980 latches/s	0.5% MAD	+1.6%

Versions and interpretation

• Effect Machine: 0.3.0
• XState 5: 5.32.5
• XState 6 alpha: 6.0.0-alpha.31
• Effect runtime primitives: 4.0.0-beta.107

Higher throughput is better; lower heap is better. Variability is the median absolute deviation across independent processes, relative to their median. Runtime measurements on shared GitHub-hosted hardware remain informational, so small differences should be confirmed across multiple workflow runs.