axon-lang 1.38.5

AXON v1.5.1 — first crates.io publication of the AXON language full-stack runtime. Lexer/parser/type-checker/IR generator (re-exported from axon-frontend) plus the native Rust runtime: typed channels (TypedEventBus with QoS×5, π-calculus mobility, capability extrusion via shield D8 — Fase 13.f.2), Free Monad CPS handlers (Fase 2), lease kernel + reconcile loop (Fase 3+5), Epistemic Security Kernel (ESK Fase 6), Trust Types + ReplayLog (Fase 11.a+11.c), Stateful PEM over WebSocket (Fase 11.d), Ontological Tool Synthesis (Fase 11.e), Mobile Typed Channels (Fase 13). Crate publishes as `axon-lang` to mirror the Python PyPI package; library import remains `use axon::*` so existing call sites keep working unchanged.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
//! §Fase 33.y.f — Cognitive primitives (Fase 11 neuro-symbolic).
//!
//! Ten variants graduated in 33.y.f:
//!
//! 1. **`Remember`** — Persist a value to the cognitive memory.
//!    Write-through: always updates `ctx.let_bindings`; when
//!    `ctx.pem_backend` is `Some(_)`, also persists to PEM as a
//!    [`crate::pem::state::MemoryEntry`] in the session's
//!    [`crate::pem::state::CognitiveState`].
//!
//! 2. **`Recall`** — Restore a value from the cognitive memory.
//!    Read-back: when `ctx.pem_backend` is `Some(_)`, restores
//!    `CognitiveState` + searches `short_term_memory` for the
//!    requested key; falls back to `ctx.let_bindings` lookup; binds
//!    the result under the `query` key in `ctx.let_bindings`.
//!
//! 3. **`Forge`** — Payload-free in v1.25.0 IR. Emits canonical
//!    `step_type: "forge"` wire shape (StepStart + StepComplete, 0
//!    tokens). Future IR extensions wire a body via a public helper.
//!
//! 4-10. **`Focus`, `Associate`, `Aggregate`, `Explore`, `Ingest`,
//!    `Navigate`, `Corroborate`** — All seven reuse the pure-shape
//!    async core ([`crate::flow_dispatcher::pure_shape::run_pure_shape`])
//!    with each variant's cognitive framing addendum reflected in
//!    the system prompt. The user prompt is built from the IR
//!    fields (target / strategy / etc.). For stub backend each
//!    handler emits 1 chunk of `"(stub)"` byte-equal with 33.y.c
//!    pure-shape D4 invariant.
//!
//! # PEM integration
//!
//! The optional `pem_backend` field on `DispatchCtx` carries an
//! `Arc<dyn PersistenceBackend>`. When set, Remember/Recall route
//! through `persist` / `restore` calls; when None, both degrade
//! gracefully to `let_bindings`-only operation (in-memory baseline
//! that matches the canonical adopter unit-test path).
//!
//! D-letter anchors:
//! - **D1** — every cognitive variant has a NAMED async handler;
//!   exhaustive match in `dispatch_node`.
//! - **D3** — cancel checked at every `.await` boundary.
//! - **D6** — pure-shape-routed handlers (Focus/Associate/...) push
//!   StepAuditRecord via the shared core; Remember/Recall do NOT
//!   push audit rows (they're cognitive-state mutations, not
//!   wire-LLM steps).
//! - **D7** — every error case routes through DispatchError; PEM
//!   `persist`/`restore` errors surface as
//!   `DispatchError::BackendError { name: "pem", ... }`.
//! - **D10** — sync-runner parity: Remember binds + Recall reads
//!   via `let_bindings` identically to the principled cognitive-
//!   state semantics the sync runner adopts; PEM write-through is
//!   an enterprise-tier extension (transparent to the wire +
//!   binding semantics).

use crate::flow_dispatcher::pure_shape::{run_pure_shape, PureShapeStep};
use crate::flow_dispatcher::{DispatchCtx, DispatchError, NodeOutcome};
use crate::flow_execution_event::{now_ms, FlowExecutionEvent};
use crate::ir_nodes::{
    IRAggregateStep, IRAssociateStep, IRCorroborateStep, IRExploreStep, IRFocusStep,
    IRForgeBlock, IRIngestStep, IRNavigateStep, IRRecallStep, IRRememberStep,
};

// ────────────────────────────────────────────────────────────────────
//  Remember — PEM write-through + let_bindings
// ────────────────────────────────────────────────────────────────────

/// Persist `expression`'s value to the cognitive memory under
/// `memory_target`.
///
/// Resolution order for `expression`:
/// 1. If `expression` is a key in `ctx.let_bindings`, use its value.
/// 2. Otherwise treat `expression` as a literal string.
///
/// Write order:
/// 1. Always insert `value` into `ctx.let_bindings[memory_target]`
///    (in-memory baseline; matches sync-runner semantics).
/// 2. When `ctx.pem_backend` is `Some(_)`, additionally persist
///    the value as a [`crate::pem::state::MemoryEntry`] into the
///    session's `CognitiveState.short_term_memory` (write-through).
///
/// # Wire shape
///
/// Emits StepStart + StepComplete with `step_type: "remember"`.
/// No StepToken (Remember is a cognitive-state mutation, not an
/// LLM dispatch). `tokens_emitted` = 0.
///
/// # Returns
///
/// `NodeOutcome::Completed { output: <resolved-value>,
/// tokens_emitted: 0, step_index: <reserved> }`. The `output`
/// reflects what was bound so downstream `last_output` capture
/// in orchestration handlers (Conditional / ForIn body
/// aggregation) sees the bound value.
pub async fn run_remember(
    node: &IRRememberStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    if ctx.cancel.is_cancelled() {
        return Err(DispatchError::UpstreamCancelled);
    }

    let step_index = ctx.step_counter;
    ctx.step_counter += 1;

    // Resolve `expression` — let_bindings reference takes priority
    // over literal interpretation.
    let value = ctx
        .let_bindings
        .get(&node.expression)
        .cloned()
        .unwrap_or_else(|| node.expression.clone());

    emit_step_start(ctx, &step_name_for_remember(node), step_index, "remember")?;

    // Always update let_bindings (in-memory baseline).
    ctx.let_bindings
        .insert(node.memory_target.clone(), value.clone());

    // Write-through to PEM when backend is wired. PEM errors
    // surface as DispatchError::BackendError so the SSE handler
    // emits a structured axon.error rather than silently dropping
    // the cognitive state.
    if let Some(backend) = ctx.pem_backend.clone() {
        write_through_pem(&backend, ctx, &node.memory_target, &value).await?;
    }

    emit_step_complete(
        ctx,
        &step_name_for_remember(node),
        step_index,
        &value,
        0,
    )?;

    Ok(NodeOutcome::Completed {
        output: value,
        tokens_emitted: 0,
        step_index,
    })
}

fn step_name_for_remember(node: &IRRememberStep) -> String {
    if node.memory_target.is_empty() {
        "Remember".to_string()
    } else {
        node.memory_target.clone()
    }
}

async fn write_through_pem(
    backend: &std::sync::Arc<dyn crate::pem::PersistenceBackend>,
    ctx: &DispatchCtx,
    key: &str,
    value: &str,
) -> Result<(), DispatchError> {
    use crate::pem::state::{CognitiveState, MemoryEntry};
    use chrono::{Duration as ChronoDuration, Utc};

    // Restore existing state; create a fresh one when not found.
    let mut state = match backend.restore(&ctx.session_id).await {
        Ok(s) => s,
        Err(_) => CognitiveState::new(&ctx.session_id, &ctx.tenant_id, &ctx.flow_name),
    };

    state.short_term_memory.push(MemoryEntry {
        key: key.to_string(),
        payload: serde_json::Value::String(value.to_string()),
        symbolic_refs: Vec::new(),
        stored_at: Utc::now(),
    });
    state.last_updated_at = Utc::now();

    backend
        .persist(&ctx.session_id, &state, ChronoDuration::hours(24))
        .await
        .map_err(|e| DispatchError::BackendError {
            name: "pem".to_string(),
            message: format!("{e:?}"),
        })?;

    Ok(())
}

// ────────────────────────────────────────────────────────────────────
//  Recall — PEM read-back + let_bindings fallback
// ────────────────────────────────────────────────────────────────────

/// Restore a value from the cognitive memory.
///
/// Read order:
/// 1. When `ctx.pem_backend` is `Some(_)`, restore `CognitiveState`
///    + search `short_term_memory` for the latest entry with
///    `key == memory_source`.
/// 2. Otherwise (or when PEM restore returns NotFound / no
///    matching entry), fall back to `ctx.let_bindings[memory_source]`.
/// 3. When neither resolves, the recalled value is the empty string.
///
/// The resolved value is bound under `ctx.let_bindings[query]` so
/// subsequent steps reference it via the adopter-declared name.
///
/// # Wire shape
///
/// Same as Remember: StepStart + StepComplete with `step_type:
/// "recall"`, 0 StepTokens.
pub async fn run_recall(
    node: &IRRecallStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    if ctx.cancel.is_cancelled() {
        return Err(DispatchError::UpstreamCancelled);
    }

    let step_index = ctx.step_counter;
    ctx.step_counter += 1;

    emit_step_start(ctx, &step_name_for_recall(node), step_index, "recall")?;

    let resolved = resolve_recall_value(node, ctx).await;

    // Bind the recalled value into let_bindings under `query`.
    ctx.let_bindings
        .insert(node.query.clone(), resolved.clone());

    emit_step_complete(
        ctx,
        &step_name_for_recall(node),
        step_index,
        &resolved,
        0,
    )?;

    Ok(NodeOutcome::Completed {
        output: resolved,
        tokens_emitted: 0,
        step_index,
    })
}

fn step_name_for_recall(node: &IRRecallStep) -> String {
    if node.query.is_empty() {
        "Recall".to_string()
    } else {
        node.query.clone()
    }
}

async fn resolve_recall_value(node: &IRRecallStep, ctx: &DispatchCtx) -> String {
    // 1. PEM read-back if backend is wired.
    if let Some(backend) = &ctx.pem_backend {
        if let Ok(state) = backend.restore(&ctx.session_id).await {
            // Find the LATEST entry with matching key (short_term_memory
            // accumulates over time; newest takes precedence).
            if let Some(entry) = state
                .short_term_memory
                .iter()
                .rev()
                .find(|e| e.key == node.memory_source)
            {
                if let serde_json::Value::String(s) = &entry.payload {
                    return s.clone();
                }
                // Non-string payload — canonical JSON serialization.
                return entry.payload.to_string();
            }
        }
    }

    // 2. let_bindings fallback.
    ctx.let_bindings
        .get(&node.memory_source)
        .cloned()
        .unwrap_or_default()
}

// ────────────────────────────────────────────────────────────────────
//  Forge — payload-free wire shape
// ────────────────────────────────────────────────────────────────────

/// Forge handler. In v1.25.0 the IR variant is payload-free so
/// this emits the canonical `step_type: "forge"` wire shape
/// (StepStart + StepComplete, 0 tokens). Future IR extensions
/// (a Fase 33.y.f.2 follow-up that adds a body via the AST/IR)
/// wire a recursive `dispatch_body` call from `run_forge`.
pub async fn run_forge(
    _node: &IRForgeBlock,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    if ctx.cancel.is_cancelled() {
        return Err(DispatchError::UpstreamCancelled);
    }

    let step_index = ctx.step_counter;
    ctx.step_counter += 1;

    emit_step_start(ctx, "Forge", step_index, "forge")?;
    emit_step_complete(ctx, "Forge", step_index, "", 0)?;

    Ok(NodeOutcome::Completed {
        output: String::new(),
        tokens_emitted: 0,
        step_index,
    })
}

// ────────────────────────────────────────────────────────────────────
//  Cognitive-framing handlers (7) — reuse pure_shape async core
// ────────────────────────────────────────────────────────────────────

/// Focus handler — narrow attention to an expression. Reuses the
/// pure-shape async core with the focus framing addendum.
pub async fn run_focus(
    node: &IRFocusStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    let shape = PureShapeStep {
        name: if node.expression.is_empty() {
            "Focus".to_string()
        } else {
            node.expression.clone()
        },
        user_prompt: format!("Focus on: {}", node.expression),
        framing_addendum: Some(
            "You are focusing your attention. Narrow scope to the target; surface what matters most.".into(),
        ),
        kind_slug: "focus",
        tools: Vec::new(),
    };
    run_pure_shape(shape, ctx).await
}

/// Associate handler — relate two entities via a key field.
pub async fn run_associate(
    node: &IRAssociateStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    let using_clause = if node.using_field.is_empty() {
        String::new()
    } else {
        format!(" using `{}`", node.using_field)
    };
    let shape = PureShapeStep {
        name: if node.left.is_empty() {
            "Associate".to_string()
        } else {
            format!("{}{}", node.left, node.right)
        },
        user_prompt: format!(
            "Associate {} with {}{}",
            node.left, node.right, using_clause
        ),
        framing_addendum: Some(
            "You are associating. Find the meaningful relationship; return a structured link.".into(),
        ),
        kind_slug: "associate",
        tools: Vec::new(),
    };
    run_pure_shape(shape, ctx).await
}

/// Aggregate handler — group + summarize a target with optional
/// group_by keys + alias.
pub async fn run_aggregate(
    node: &IRAggregateStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    let group_clause = if node.group_by.is_empty() {
        String::new()
    } else {
        format!(" grouped by [{}]", node.group_by.join(", "))
    };
    let alias_clause = if node.alias.is_empty() {
        String::new()
    } else {
        format!(" as `{}`", node.alias)
    };
    let shape = PureShapeStep {
        name: if node.target.is_empty() {
            "Aggregate".to_string()
        } else {
            node.target.clone()
        },
        user_prompt: format!(
            "Aggregate {}{}{}",
            node.target, group_clause, alias_clause
        ),
        framing_addendum: Some(
            "You are aggregating. Group + summarize over the declared dimensions; surface the structure.".into(),
        ),
        kind_slug: "aggregate",
        tools: Vec::new(),
    };
    run_pure_shape(shape, ctx).await
}

/// Explore handler — broad-scope exploration of a target with
/// optional result-count limit.
pub async fn run_explore(
    node: &IRExploreStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    let limit_clause = match node.limit {
        Some(n) => format!(" (top {})", n),
        None => String::new(),
    };
    let shape = PureShapeStep {
        name: if node.target.is_empty() {
            "Explore".to_string()
        } else {
            node.target.clone()
        },
        user_prompt: format!("Explore: {}{}", node.target, limit_clause),
        framing_addendum: Some(
            "You are exploring. Sample broadly; surface the most-relevant directions.".into(),
        ),
        kind_slug: "explore",
        tools: Vec::new(),
    };
    run_pure_shape(shape, ctx).await
}

/// Ingest handler — bring external data in from a source into a
/// target.
pub async fn run_ingest(
    node: &IRIngestStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    let shape = PureShapeStep {
        name: if node.target.is_empty() {
            "Ingest".to_string()
        } else {
            node.target.clone()
        },
        user_prompt: format!("Ingest from `{}` into `{}`", node.source, node.target),
        framing_addendum: Some(
            "You are ingesting. Map the source's structure into the target; preserve fidelity.".into(),
        ),
        kind_slug: "ingest",
        tools: Vec::new(),
    };
    run_pure_shape(shape, ctx).await
}

/// Navigate handler — paper §6 PIX navigation. In v1.25.0 the
/// handler ships the cognitive-framing wire shape (production-real
/// PIX traversal lands in a Fase 11.e follow-up; today the framing
/// nudges the LLM to surface its navigation path).
pub async fn run_navigate(
    node: &IRNavigateStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    let trail_clause = if node.trail_enabled { " (with trail)" } else { "" };
    let shape = PureShapeStep {
        name: if node.output_name.is_empty() {
            "Navigate".to_string()
        } else {
            node.output_name.clone()
        },
        user_prompt: format!(
            "Navigate corpus `{}` via PIX `{}` for query: {}{}",
            node.corpus_ref, node.pix_ref, node.query, trail_clause
        ),
        framing_addendum: Some(
            "You are navigating a PIX (paper §6 hidden state). Trace your reasoning path; surface the corpus regions you crossed.".into(),
        ),
        kind_slug: "navigate",
        tools: Vec::new(),
    };
    run_pure_shape(shape, ctx).await
}

/// Corroborate handler — cross-validate a navigation result against
/// the referenced `navigate_ref`.
pub async fn run_corroborate(
    node: &IRCorroborateStep,
    ctx: &mut DispatchCtx,
) -> Result<NodeOutcome, DispatchError> {
    let shape = PureShapeStep {
        name: if node.output_name.is_empty() {
            "Corroborate".to_string()
        } else {
            node.output_name.clone()
        },
        user_prompt: format!("Corroborate navigation result `{}`", node.navigate_ref),
        framing_addendum: Some(
            "You are corroborating. Cross-validate independently; surface agreement strength + disagreements.".into(),
        ),
        kind_slug: "corroborate",
        tools: Vec::new(),
    };
    run_pure_shape(shape, ctx).await
}

// ────────────────────────────────────────────────────────────────────
//  Wire-event helpers (shared with Remember/Recall/Forge)
// ────────────────────────────────────────────────────────────────────

fn emit_step_start(
    ctx: &mut DispatchCtx,
    step_name: &str,
    step_index: usize,
    step_type: &str,
) -> Result<(), DispatchError> {
    ctx.tx
        .send(FlowExecutionEvent::StepStart {
            step_name: step_name.to_string(),
            step_index,
            step_type: step_type.to_string(),
            timestamp_ms: now_ms(),
        })
        .map_err(|_| DispatchError::ChannelClosed)
}

fn emit_step_complete(
    ctx: &mut DispatchCtx,
    step_name: &str,
    step_index: usize,
    full_output: &str,
    tokens_output: u64,
) -> Result<(), DispatchError> {
    ctx.tx
        .send(FlowExecutionEvent::StepComplete {
            step_name: step_name.to_string(),
            step_index,
            success: true,
            full_output: full_output.to_string(),
            tokens_input: 0,
            tokens_output,
            timestamp_ms: now_ms(),
        })
        .map_err(|_| DispatchError::ChannelClosed)
}

// ────────────────────────────────────────────────────────────────────
//  Unit tests
// ────────────────────────────────────────────────────────────────────

#[cfg(test)]
mod tests {
    use super::*;
    use crate::cancel_token::CancellationFlag;
    use crate::ir_nodes::*;
    use crate::pem::InMemoryBackend;
    use std::sync::Arc;
    use tokio::sync::mpsc;

    fn fresh_ctx() -> (
        DispatchCtx,
        mpsc::UnboundedReceiver<FlowExecutionEvent>,
    ) {
        let (tx, rx) = mpsc::unbounded_channel();
        let ctx = DispatchCtx::new(
            "TestFlow",
            "stub",
            "",
            CancellationFlag::new(),
            tx,
        );
        (ctx, rx)
    }

    // ── Remember ──────────────────────────────────────────────────────

    #[tokio::test]
    async fn run_remember_literal_value_binds_to_let_bindings() {
        let (mut ctx, _rx) = fresh_ctx();
        let node = IRRememberStep {
            node_type: "remember",
            source_line: 0,
            source_column: 0,
            expression: "us-east-1".into(),
            memory_target: "region".into(),
        };
        let outcome = run_remember(&node, &mut ctx).await.unwrap();
        match outcome {
            NodeOutcome::Completed { output, tokens_emitted, .. } => {
                assert_eq!(output, "us-east-1");
                assert_eq!(tokens_emitted, 0);
            }
            other => panic!("expected Completed, got {other:?}"),
        }
        assert_eq!(ctx.let_bindings.get("region").unwrap(), "us-east-1");
    }

    #[tokio::test]
    async fn run_remember_resolves_expression_through_let_bindings() {
        let (mut ctx, _rx) = fresh_ctx();
        ctx.let_bindings.insert("upstream".into(), "computed-X".into());
        let node = IRRememberStep {
            node_type: "remember",
            source_line: 0,
            source_column: 0,
            expression: "upstream".into(),
            memory_target: "snapshot".into(),
        };
        run_remember(&node, &mut ctx).await.unwrap();
        assert_eq!(ctx.let_bindings.get("snapshot").unwrap(), "computed-X");
    }

    #[tokio::test]
    async fn run_remember_with_pem_persists_to_backend() {
        let backend: Arc<dyn crate::pem::PersistenceBackend> =
            Arc::new(InMemoryBackend::default());
        let (tx, _rx) = mpsc::unbounded_channel();
        let mut ctx = DispatchCtx::new(
            "F",
            "stub",
            "",
            CancellationFlag::new(),
            tx,
        )
        .with_pem(backend.clone())
        .with_session_id("session-1");

        let node = IRRememberStep {
            node_type: "remember",
            source_line: 0,
            source_column: 0,
            expression: "persisted-value".into(),
            memory_target: "key1".into(),
        };
        run_remember(&node, &mut ctx).await.unwrap();

        // Verify PEM has the entry.
        let state = backend.restore("session-1").await.unwrap();
        assert_eq!(state.short_term_memory.len(), 1);
        assert_eq!(state.short_term_memory[0].key, "key1");
    }

    // ── Recall ────────────────────────────────────────────────────────

    #[tokio::test]
    async fn run_recall_from_let_bindings_when_no_pem() {
        let (mut ctx, _rx) = fresh_ctx();
        ctx.let_bindings.insert("region".into(), "us-east-1".into());
        let node = IRRecallStep {
            node_type: "recall",
            source_line: 0,
            source_column: 0,
            query: "current_region".into(),
            memory_source: "region".into(),
        };
        let outcome = run_recall(&node, &mut ctx).await.unwrap();
        match outcome {
            NodeOutcome::Completed { output, .. } => {
                assert_eq!(output, "us-east-1");
            }
            other => panic!("expected Completed, got {other:?}"),
        }
        assert_eq!(
            ctx.let_bindings.get("current_region").unwrap(),
            "us-east-1"
        );
    }

    #[tokio::test]
    async fn run_recall_from_pem_when_backend_set() {
        let backend: Arc<dyn crate::pem::PersistenceBackend> =
            Arc::new(InMemoryBackend::default());
        let (tx, _rx) = mpsc::unbounded_channel();
        let mut ctx = DispatchCtx::new(
            "F",
            "stub",
            "",
            CancellationFlag::new(),
            tx,
        )
        .with_pem(backend.clone())
        .with_session_id("sess");

        // Plant a memory entry via Remember.
        run_remember(
            &IRRememberStep {
                node_type: "remember",
                source_line: 0,
                source_column: 0,
                expression: "value-from-pem".into(),
                memory_target: "pem_key".into(),
            },
            &mut ctx,
        )
        .await
        .unwrap();

        // Now Recall via PEM.
        let outcome = run_recall(
            &IRRecallStep {
                node_type: "recall",
                source_line: 0,
                source_column: 0,
                query: "recalled".into(),
                memory_source: "pem_key".into(),
            },
            &mut ctx,
        )
        .await
        .unwrap();
        match outcome {
            NodeOutcome::Completed { output, .. } => {
                assert_eq!(output, "value-from-pem");
            }
            other => panic!("expected Completed, got {other:?}"),
        }
    }

    #[tokio::test]
    async fn run_recall_missing_key_returns_empty_string() {
        let (mut ctx, _rx) = fresh_ctx();
        let node = IRRecallStep {
            node_type: "recall",
            source_line: 0,
            source_column: 0,
            query: "x".into(),
            memory_source: "never_set".into(),
        };
        let outcome = run_recall(&node, &mut ctx).await.unwrap();
        match outcome {
            NodeOutcome::Completed { output, .. } => assert_eq!(output, ""),
            other => panic!("expected Completed, got {other:?}"),
        }
    }

    // ── Forge ─────────────────────────────────────────────────────────

    #[tokio::test]
    async fn run_forge_emits_canonical_wire_shape() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRForgeBlock {
            node_type: "forge",
            source_line: 0,
            source_column: 0,
        };
        let outcome = run_forge(&node, &mut ctx).await.unwrap();
        match outcome {
            NodeOutcome::Completed { output, tokens_emitted, .. } => {
                assert_eq!(output, "");
                assert_eq!(tokens_emitted, 0);
            }
            other => panic!("expected Completed, got {other:?}"),
        }
        let mut events = Vec::new();
        while let Ok(ev) = rx.try_recv() {
            events.push(ev);
        }
        assert_eq!(events.len(), 2);
        match &events[0] {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "forge");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    // ── Cognitive framing handlers ────────────────────────────────────

    #[tokio::test]
    async fn run_focus_emits_focus_slug() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRFocusStep {
            node_type: "focus",
            source_line: 0,
            source_column: 0,
            expression: "key_insight".into(),
        };
        let _ = run_focus(&node, &mut ctx).await.unwrap();
        let ev = rx.try_recv().unwrap();
        match ev {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "focus");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    #[tokio::test]
    async fn run_associate_emits_associate_slug() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRAssociateStep {
            node_type: "associate",
            source_line: 0,
            source_column: 0,
            left: "A".into(),
            right: "B".into(),
            using_field: "id".into(),
        };
        run_associate(&node, &mut ctx).await.unwrap();
        let ev = rx.try_recv().unwrap();
        match ev {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "associate");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    #[tokio::test]
    async fn run_aggregate_emits_aggregate_slug() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRAggregateStep {
            node_type: "aggregate",
            source_line: 0,
            source_column: 0,
            target: "events".into(),
            group_by: vec!["region".into()],
            alias: "by_region".into(),
        };
        run_aggregate(&node, &mut ctx).await.unwrap();
        let ev = rx.try_recv().unwrap();
        match ev {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "aggregate");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    #[tokio::test]
    async fn run_explore_emits_explore_slug() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRExploreStep {
            node_type: "explore",
            source_line: 0,
            source_column: 0,
            target: "hypothesis_space".into(),
            limit: Some(5),
        };
        run_explore(&node, &mut ctx).await.unwrap();
        let ev = rx.try_recv().unwrap();
        match ev {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "explore");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    #[tokio::test]
    async fn run_ingest_emits_ingest_slug() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRIngestStep {
            node_type: "ingest",
            source_line: 0,
            source_column: 0,
            source: "external_api".into(),
            target: "raw".into(),
        };
        run_ingest(&node, &mut ctx).await.unwrap();
        let ev = rx.try_recv().unwrap();
        match ev {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "ingest");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    #[tokio::test]
    async fn run_navigate_emits_navigate_slug() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRNavigateStep {
            node_type: "navigate",
            source_line: 0,
            source_column: 0,
            pix_ref: "main_pix".into(),
            corpus_ref: "law_corpus".into(),
            query: "interpret_clause".into(),
            trail_enabled: true,
            output_name: "nav_result".into(),
        };
        run_navigate(&node, &mut ctx).await.unwrap();
        let ev = rx.try_recv().unwrap();
        match ev {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "navigate");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    #[tokio::test]
    async fn run_corroborate_emits_corroborate_slug() {
        let (mut ctx, mut rx) = fresh_ctx();
        let node = IRCorroborateStep {
            node_type: "corroborate",
            source_line: 0,
            source_column: 0,
            navigate_ref: "nav_result".into(),
            output_name: "validated".into(),
        };
        run_corroborate(&node, &mut ctx).await.unwrap();
        let ev = rx.try_recv().unwrap();
        match ev {
            FlowExecutionEvent::StepStart { step_type, .. } => {
                assert_eq!(step_type, "corroborate");
            }
            e => panic!("expected StepStart, got {e:?}"),
        }
    }

    // ── Cancel guards ────────────────────────────────────────────────

    #[tokio::test]
    async fn every_cognitive_handler_short_circuits_on_cancel() {
        let cancel = CancellationFlag::new();
        cancel.cancel();
        let (tx, _rx) = mpsc::unbounded_channel();
        let mut ctx = DispatchCtx::new("F", "stub", "", cancel, tx);

        // Remember
        let r = IRRememberStep {
            node_type: "remember",
            source_line: 0,
            source_column: 0,
            expression: "x".into(),
            memory_target: "y".into(),
        };
        assert!(matches!(
            run_remember(&r, &mut ctx).await,
            Err(DispatchError::UpstreamCancelled)
        ));

        // Recall
        let r = IRRecallStep {
            node_type: "recall",
            source_line: 0,
            source_column: 0,
            query: "q".into(),
            memory_source: "k".into(),
        };
        assert!(matches!(
            run_recall(&r, &mut ctx).await,
            Err(DispatchError::UpstreamCancelled)
        ));

        // Forge
        assert!(matches!(
            run_forge(
                &IRForgeBlock {
                    node_type: "forge",
                    source_line: 0,
                    source_column: 0,
                },
                &mut ctx,
            )
            .await,
            Err(DispatchError::UpstreamCancelled)
        ));

        // Cognitive-framing handlers — all go through run_pure_shape
        // which has its own cancel guard.
        assert!(matches!(
            run_focus(
                &IRFocusStep {
                    node_type: "focus",
                    source_line: 0,
                    source_column: 0,
                    expression: "x".into(),
                },
                &mut ctx,
            )
            .await,
            Err(DispatchError::UpstreamCancelled)
        ));
    }
}