nullhack · nullhack · May 5, 2026 · May 5, 2026 · May 5, 2026
diff --git a/.gitignore b/.gitignore
@@ -175,3 +175,10 @@ cython_debug/
 .opencode/
 .templates/
 AGENTS.md
+
+# smith managed
+.flowr/
+.opencode/
+.templates/
+AGENTS.md
+# end smith managed
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,37 @@
 
 All notable changes to this project will be documented in this file.
 
+## [v0.5.0+20260505] - Fine Sift - 2026-05-05
+
+### Added
+
+- **Subflow exit resolution**: when a subflow exits, the exit name is resolved through the parent flow's transition map to determine the actual target state; previously the exit name was used directly as a state ID, causing sessions to land on invalid states
+- **Subflow chaining**: after exiting a subflow, if the resolved target state has a `flow:` field, the stack is pushed again to enter the next subflow atomically (e.g., discovery-flow → exit → architecture-flow)
+- **`session init` auto-enters subflow**: when the first state has a `flow:` field, `session init` pushes the stack and enters the subflow's initial state automatically
+- **`next` shows all transitions**: the `next` command now displays ALL transitions including blocked/guarded ones, with trigger→target mapping and status markers (`[blocked]` + condition hints)
+- **`next` JSON output uses `transitions` array**: replaces the old `next: [strings]` with `transitions: [{trigger, target, status, conditions}]` — a breaking change (pre-release)
+- **`states --session`**: lists states in the current (sub)flow resolved from the session
+- **`validate --session`**: validates the current (sub)flow resolved from the session
+- **`check --session <trigger>`**: correctly shows transition conditions for the given trigger (previously the argument was silently captured by argparse as `flow_file`)
+- **Session-aware dispatch refactor**: extracted `_dispatch_session_command()` to reduce cyclomatic complexity; unified session-aware routing for all commands
+- **Post-mortem**: `PM_20260505_subflow-mechanism-non-functional` documenting the two critical bugs and testing gap
+
+### Changed
+
+- **`flowr/domain/loader.py`**: `resolve_subflows()` now tries the `flow` field path as-is first, then appends `.yaml` if not found — making the `.yaml` extension optional in flow definitions
+- **`flowr/__main__.py`**: new helper functions `_find_flow_file()`, `_enter_subflow()`, `_resolve_subflow_exit()`, `_build_transition_list()`, `_format_transitions_text()`; `_apply_session_transition()` gains `flows_dir` parameter for parent flow resolution; `_cmd_next` and `_cmd_next_session` use rich transition output; argparse for `validate` and `states` now accept optional `flow_file` and `--session`
+- **`flowr/cli/session_cmd.py`**: `cmd_session_init` auto-enters initial subflow when first state has `flow:` field
+- **JSON is now default CLI output**: `--json` flag replaced with `--text` — JSON is the default for all commands; use `--text` for human-readable output
+- **ADR_20260426_subflow_resolution** amended: `.yaml` extension now optional with fallback-append
+
+### Fixed
+
+- **Subflow path resolution**: `resolve_subflows()` failed for flow references without `.yaml` extension (e.g., `flow: discovery-flow`) — now tries as-is first, then appends `.yaml`
+- **Subflow exit state resolution**: `pop_stack(target)` used exit name directly as state ID, producing invalid states — now resolves through parent transition map
+- **`check --session <target>` argparse capture**: target argument was silently consumed as `flow_file` positional — now correctly routed as target trigger name
+- **Test fixture gap**: added tests for flow references without `.yaml` extension and subflow exit resolution/chaining
+- **Stack frame state bug**: `_enter_subflow()` recorded the pre-transition state instead of the subflow wrapper state in the stack frame, causing exit resolution to look up the wrong parent `next` map — now records the target (subflow wrapper) state
+
 ## [v0.4.0+20260502] - Refined Semolina - 2026-05-02
 
 ### Added

diff --git a/README.md b/README.md
@@ -43,9 +43,10 @@ flowr defines a YAML format for non-deterministic state machines with per-state
 ```
 flowr validate deploy.yaml          →  valid: True
 flowr states deploy.yaml            →  prepare, execute, review
-flowr next deploy.yaml review       →  approve (guarded), reject
+flowr next deploy.yaml review       →  approve → deployed [blocked]  need: score=>=80
+                                     →  reject → failed
 flowr transition deploy.yaml review approve --evidence score=85
-                                    →  from: review, to: deployed
+                                     →  from: review, to: deployed
 flowr session init deploy-flow       →  session created at state: prepare
 flowr --session transition approve  →  from: prepare, to: review
 flowr mermaid deploy.yaml           →  stateDiagram-v2 ...
@@ -55,7 +56,7 @@ flowr mermaid deploy.yaml           →  stateDiagram-v2 ...
 
 **Query.** States, transitions, conditions, attributes — ask any question the flow can answer.
 
-**Sessions.** Init, show, set-state, transition, list. Subflow push/pop for nested workflows. One `--session` flag turns any command session-aware.
+**Sessions.** Init, show, set-state, transition, list. Subflow push/pop for nested workflows. Auto-enters initial subflow on `session init`. One `--session` flag turns any command session-aware (including `validate` and `states`).
 
 **Config.** `flowr config` shows where every value comes from — default, pyproject.toml, or CLI override.
 
@@ -111,8 +112,8 @@ review
 
 $ flowr next deploy.yaml review
 state: review
-next: approve (guarded)
-next: reject
+  approve → deployed [blocked]  need: score=>=80
+  reject → failed
 
 $ flowr transition deploy.yaml review approve --evidence score=85
 from: review
@@ -152,15 +153,15 @@ default_session = default  (default)
 | `flowr validate <flow>` | Validate a flow definition |
 | `flowr states <flow>` | List all state ids |
 | `flowr check <flow> <state> [<target>]` | Show state details or transition conditions |
-| `flowr next <flow> <state> [--evidence K=V]` | Show valid next transitions |
+| `flowr next <flow> <state> [--evidence K=V]` | Show all transitions with trigger→target and condition status |
 | `flowr transition <flow> <state> <trigger> [--evidence K=V]` | Compute next state |
 | `flowr mermaid <flow>` | Export as Mermaid state diagram |
-| `flowr session init <flow> [--name NAME]` | Create a new session at the flow's initial state |
+| `flowr session init <flow> [--name NAME]` | Create a new session (auto-enters initial subflow) |
 | `flowr session show [--name NAME] [--format FORMAT]` | Display current session state |
 | `flowr session set-state <state> [--name NAME]` | Update the session's current state |
 | `flowr session list [--format FORMAT]` | List all sessions |
 | `flowr config [--json]` | Show resolved configuration with sources |
-| `flowr --session <command>` | Run a command using session state |
+| `flowr --session <command>` | Run a command using session state (works with validate, states, check, next, transition) |
 
 `<flow>` accepts a file path or a short flow name (resolved from `.flowr/flows/`). Use `--flows-dir` to override the configured flows directory. All commands accept `--json` for machine-readable output. Evidence: `--evidence key=value` (repeatable) or `--evidence-json '{"key": "value"}'`.
 

diff --git a/docs/adr/ADR_20260426_subflow_resolution.md b/docs/adr/ADR_20260426_subflow_resolution.md
@@ -17,17 +17,19 @@ When a state references a subflow via its `flow` field, the CLI needs to locate
 
 ## Decision
 
-Subflow lookup resolves the `flow` field as a relative path from the root flow's directory, including file extension. Subflow entry is displayed as `<flow-name>/<first-state-id>`.
+Subflow lookup resolves the `flow` field as a relative path from the root flow's directory. The resolver tries the path as-is first; if the file does not exist, it appends `.yaml` and tries again. This makes the `.yaml` extension optional — flow authors can write `flow: discovery-flow` or `flow: discovery-flow.yaml`. Subflow entry is displayed as `<flow-name>/<first-state-id>`.
+
+**Amendment (2026-05-05):** The original decision required the `.yaml` extension explicitly. This was changed because real production flows omit the extension (e.g., `flow: discovery-flow`), and requiring it added friction. The fallback-append approach keeps explicit extensions working while also supporting bare names.
 
 ## Reason
 
-Convention-over-configuration with path flexibility; matches project layout; supports subdirectories; no extra CLI flags needed.
+Convention-over-configuration with path flexibility; matches project layout; supports subdirectories; no extra CLI flags needed. The extension-optional fallback reduces ceremony for the common case (same directory, `.yaml` files) while preserving support for explicit paths and subdirectories.
 
 ## Alternatives Considered
 
 - **Explicit --flows-dir flag**: over-engineered for v1; adds cognitive load
 - **Walk parent directories**: fragile; could find wrong files
-- **Auto-append .yaml extension**: adds magic; explicit extension is simpler
+- **Require .yaml extension always**: original decision; rejected after production flows showed authors prefer bare names
 - **Subflow output as just first state**: loses context about which subflow you're entering
 - **Subflow output as just flow name**: loses context about entry point
 
@@ -36,11 +38,19 @@ Convention-over-configuration with path flexibility; matches project layout; sup
 - (+) Zero configuration; works with existing flow file layout
 - (+) Supports subdirectories and relative paths
 - (+) Clear, unambiguous output showing subflow name + entry state
-- (-) Flow field must include `.yaml` extension — existing reference YAML files need updating
+- (+) `.yaml` extension is optional — bare flow names work (e.g., `flow: discovery-flow`)
 - (-) Flow field has dual meaning (lookup path vs canonical flow name from loaded YAML)
 
 ## Risk Assessment
 
 | Risk | Probability | Impact | Mitigation | Accepted? |
 |------|------------|--------|------------|-----------|
-| Flow field has dual meaning (lookup path vs canonical flow name) | Low | Medium | Ambiguity is mitigated by convention; loader extracts canonical name from loaded YAML | Yes |
+| Flow field has dual meaning (lookup path vs canonical flow name) | Low | Medium | Ambiguity is mitigated by convention; loader extracts canonical name from loaded YAML | Yes |
+| Bare name matches wrong file in subdirectory | Low | Low | Resolution is relative to root flow's directory; convention keeps flows flat | Yes |
+
+## Changes
+
+| Date | Change | Reason |
+|------|--------|--------|
+| 2026-04-26 | Initial decision: require `.yaml` extension | Original ADR |
+| 2026-05-05 | Made `.yaml` extension optional with fallback | Production flows use bare names; requiring extension was friction (PM_20260505_subflow-mechanism-non-functional) |
diff --git a/docs/features/backlog/subflow-transition-overhaul.feature b/docs/features/backlog/subflow-transition-overhaul.feature
@@ -0,0 +1,161 @@
+Feature: Subflow Transition Overhaul
+
+  The subflow mechanism (push/pop stack for nested flows) is completely
+  non-functional for real flows due to two critical bugs in path resolution
+  and exit handling. Additionally, the `next` command hides critical
+  navigation information — trigger names, guarded transitions, and evidence
+  requirements — making autonomous agent navigation impossible.
+
+  This feature fixes the subflow mechanism, enhances `next` to show the
+  complete navigation picture, and improves session command robustness.
+
+  Depends on: session-management (core), session-management-extended.
+
+  Status: ELICITING
+
+  Rules (Business):
+  - Flow references without `.yaml` extension are resolved by appending `.yaml` if the bare path doesn't exist
+  - Subflow exit resolves through the parent flow's transition map, not by using the exit name directly
+  - Subflow chaining: after exiting one subflow, if the resolved target enters another subflow, the stack is pushed again
+  - `session init` auto-enters the initial subflow if the first state has a `flow:` field
+  - `next` always shows ALL transitions including blocked/guarded ones, with status markers
+  - `next` output shows trigger→target mapping with inline condition requirements
+  - `next` JSON output uses `transitions` array of objects with `trigger`, `target`, `status`, `conditions`
+  - `check --session <target>` correctly shows transition conditions
+  - `states --session` and `validate --session` resolve the current flow from session
+
+  Constraints:
+  - Non-session commands remain backward compatible
+  - `next` JSON output is a breaking change: `next` array of strings replaced with `transitions` array of objects
+  - Domain layer (Session, SessionStackFrame) changes are minimal — fixes are in CLI/transition logic
+
+  ## Questions
+
+  | ID | Question | Status | Answer / Assumption |
+  |----|----------|--------|---------------------|
+  | Q1 | Should `next` show all transitions or require `--all` flag? | Resolved | Always show all — agents need the full picture |
+  | Q2 | Should `next` JSON preserve backward compatibility? | Resolved | No — clean break, replace `next` array with `transitions` objects |
+  | Q3 | Should `set-state` support crossing flow boundaries? | Open | Phase 3 — may add `--flow` flag for recovery scenarios |
+
+  ## Changes
+
+  | Session | Q-IDs | Change |
+  |---------|-------|--------|
+  | 2026-05-05 S1 | Q1-Q3 | Created: subflow resolution, exit handling, next overhaul, session robustness |
+
+  Rule: Subflow Path Resolution
+    As a flowr user
+    I want flow references without file extensions to resolve correctly
+    So that I can use clean flow names in YAML definitions
+
+    @id:sf-001
+    Example: Flow reference without .yaml extension resolves correctly
+      Given a flow YAML with `flow: discovery-flow` referencing a file `discovery-flow.yaml`
+      When the CLI resolves subflows
+      Then the subflow is loaded successfully
+
+    @id:sf-002
+    Example: Flow reference with .yaml extension still works
+      Given a flow YAML with `flow: child.yaml` referencing a file `child.yaml`
+      When the CLI resolves subflows
+      Then the subflow is loaded successfully
+
+  Rule: Subflow Exit Resolution
+    As a flowr user
+    I want subflow exits to correctly resolve through the parent flow's transitions
+    So that my session lands on the correct next state after completing a subflow
+
+    @id:sf-003
+    Example: Subflow exit resolves parent transition target
+      Given a session inside discovery-flow with stack frame pointing to main-flow/discovery
+      And discovery-flow exits with `complete`
+      And main-flow/discovery maps `complete → architecture`
+      When the user transitions with the exit trigger
+      Then the session pops the stack and lands at main-flow/architecture
+
+    @id:sf-004
+    Example: Subflow chaining enters next subflow after exit
+      Given a session exiting discovery-flow back to main-flow
+      And the resolved target `architecture` has `flow: architecture-flow`
+      When the subflow exit resolves to architecture
+      Then the session pushes a new stack frame and enters architecture-flow
+
+    @id:sf-005
+    Example: Subflow exit with invalid parent state produces error
+      Given a session inside a subflow with a corrupted stack frame
+      When the subflow exit cannot find the parent state
+      Then the CLI prints a clear error indicating the parent state is invalid
+
+  Rule: Session Init Enters Subflow
+    As a flowr user
+    I want session init to automatically enter the initial subflow
+    So that I can start working immediately without an extra transition step
+
+    @id:sf-006
+    Example: Session init auto-enters subflow when initial state has flow field
+      Given a flow whose initial state has `flow: discovery-flow`
+      When the user runs flowr session init main-flow
+      Then the session is created inside discovery-flow with a stack frame pointing to main-flow
+
+    @id:sf-007
+    Example: Session init without subflow works as before
+      Given a flow whose initial state has no `flow:` field
+      When the user runs flowr session init simple-flow
+      Then the session is created at the initial state with no stack
+
+  Rule: Next Shows Full Transition Map
+    As a flowr user
+    I want to see all transitions with trigger names, targets, and condition requirements
+    So that I can navigate without reading raw YAML files
+
+    @id:sf-008
+    Example: Next shows trigger→target mapping for all transitions
+      Given a session at a state with transitions `needs_full_discovery → event-storming`, `needs_scope_only → scope-boundary`
+      When the user runs flowr next --session
+      Then the output shows each trigger name alongside its target state
+
+    @id:sf-009
+    Example: Next shows blocked guarded transitions with condition hints
+      Given a session at a state with a guarded transition requiring `committed_to_main_locally=verified`
+      When the user runs flowr next --session without evidence
+      Then the blocked transition appears with a marker showing the required evidence
+
+    @id:sf-010
+    Example: Next shows passing guarded transitions
+      Given a session at a state with a guarded transition requiring `committed_to_main_locally=verified`
+      When the user runs flowr next --session --evidence committed_to_main_locally=verified
+      Then the transition appears as passing/open
+
+    @id:sf-011
+    Example: Next JSON output uses transitions array with full details
+      Given a session at a state with transitions
+      When the user runs flowr next --session --json
+      Then the output contains a `transitions` array where each entry has `trigger`, `target`, `status`, and `conditions`
+
+  Rule: Check Session Shows Conditions
+    As a flowr user
+    I want to check transition conditions from session mode
+    So that I know exactly what evidence to provide
+
+    @id:sf-012
+    Example: Check session with target shows transition conditions
+      Given a session at a state with a guarded transition
+      When the user runs flowr check --session <trigger-name>
+      Then the output shows the conditions required for that transition
+
+  Rule: Session-Aware States and Validate
+    As a flowr user
+    I want to list states and validate the current flow from session
+    So that I can inspect my current (sub)flow context without specifying the flow name
+
+    @id:sf-013
+    Example: States command with --session lists current flow's states
+      Given a session inside architecture-flow
+      When the user runs flowr states --session
+      Then the output lists all states in architecture-flow
+
+    @id:sf-014
+    Example: Validate command with --session validates current flow
+      Given a session inside architecture-flow
+      When the user runs flowr validate --session
+      Then the output validates architecture-flow