Feat v0.9.8 conditional routing SDK primitive

Promote workflow branch-rule evaluation to a generic Starlark
routing.evaluate(rules, data) module available to all extensions.
10 operators, first-match-wins, no permission gate. 8 new tests.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,27 @@
 
 All notable changes to Armature are documented here.
 
+## v0.9.8 — Conditional Routing → SDK Primitive
+
+Promotes the workflow branch-rule engine to a generic Starlark SDK
+module available to all extensions — no permission required.
+
+**New Starlark module: `routing`**
+
+- `routing.evaluate(rules, data)` — evaluates an ordered list of
+  condition rules against a data dict; returns the first matching
+  rule's `target` string, or `None` if no rule matches
+- 10 operators: `exists`, `not_exists`, `eq`, `neq`, `gt`, `lt`,
+  `gte`, `lte`, `in`, `contains`
+- First-match-wins semantics
+- Domain-agnostic: uses `target` (not `target_stage`) so any
+  extension can use it for feature flags, content routing, approval
+  logic, etc.
+- Always available — pure computation, no I/O, no permission gate
+
+**Tests:** 8 new unit tests covering all operators, type coercion,
+first-match-wins, empty/missing/bad input
+
 ## v0.9.7 — Full Read/Write Workflow Starlark Module
 
 Extensions with `workflow.access` permission can now start, advance,

ROADMAP.md

@@ -137,10 +137,13 @@ circular import. Four write builtins added: `workflow.start()`,
 `instanceToDict` and `signoffToDict` helpers shared by read+write paths.
 6 new tests.
 
-**v0.9.8 — Conditional Routing → SDK Primitive**
+**v0.9.8 — Conditional Routing → SDK Primitive** *(completed)*
 
-Expose `routing.evaluate(rules, data)` as a Starlark SDK function.
+`routing.evaluate(rules, data)` Starlark builtin — a generic decision
-Branch rules become a reusable decision engine for any extension.
+engine reusable by any extension. 10 operators (exists, not_exists, eq,
+neq, gt, lt, gte, lte, in, contains), first-match-wins, returns target
+string or None. Always available (pure computation, no permission).
+8 new tests.
 
 **v0.9.9 — Surface Access via Roles**
 

VERSION

@@ -1 +1 @@
-0.9.7
+0.9.8

docs/STARLARK-REFERENCE.md

@@ -84,6 +84,24 @@ Returns `True` if the user has the permission, `False` otherwise (including
 when the user is not found). Resolves the user's groups and merges granted
 permissions — works for both kernel and extension-declared permissions.
 
+### routing
+
+Generic rule-based decision engine. Evaluates an ordered list of conditions
+against a data dict, returning the first matching rule's target string.
+
+```python
+result = routing.evaluate([
+    {"field": "priority", "op": "eq",  "value": "critical", "target": "escalation"},
+    {"field": "amount",   "op": "gt",  "value": 10000,      "target": "manager_review"},
+    {"field": "region",   "op": "in",  "value": ["EU", "UK"], "target": "gdpr_flow"},
+], stage_data)
+# Returns "escalation", "manager_review", "gdpr_flow", or None
+```
+
+Each rule is a dict with `field`, `op`, `value`, and `target`. Operators:
+`exists`, `not_exists`, `eq`, `neq`, `gt`, `lt`, `gte`, `lte`, `in`,
+`contains`. First-match-wins; returns `None` if no rule matches.
+
 ## Permission-gated modules
 
 These modules are only available if the package has the corresponding

server/sandbox/routing_module.go

@@ -0,0 +1,190 @@
+package sandbox
+
+// routing_module.go
+//
+// Starlark routing module — a generic rule-based decision engine.
+// Always available (pure computation, no I/O).
+//
+// Starlark API:
+//   result = routing.evaluate(rules, data)
+//   # result → "target_string" or None
+
+import (
+	"fmt"
+	"strings"
+
+	"go.starlark.net/starlark"
+	"go.starlark.net/starlarkstruct"
+)
+
+// BuildRoutingModule creates the "routing" Starlark module.
+// No permission required — pure computation.
+func BuildRoutingModule() *starlarkstruct.Module {
+	return MakeModule("routing", starlark.StringDict{
+		"evaluate": starlark.NewBuiltin("routing.evaluate", routingEvaluateBuiltin()),
+	})
+}
+
+// routingRule is the generic equivalent of workflow.Condition.
+// Uses "target" instead of "target_stage" to be domain-agnostic.
+type routingRule struct {
+	Field  string
+	Op     string
+	Value  any
+	Target string
+}
+
+func routingEvaluateBuiltin() func(*starlark.Thread, *starlark.Builtin, starlark.Tuple, []starlark.Tuple) (starlark.Value, error) {
+	return func(_ *starlark.Thread, b *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+		var rulesVal, dataVal starlark.Value
+		if err := starlark.UnpackPositionalArgs(b.Name(), args, kwargs, 2, &rulesVal, &dataVal); err != nil {
+			return nil, err
+		}
+
+		// Convert rules list → []routingRule
+		rulesList, ok := rulesVal.(*starlark.List)
+		if !ok {
+			return nil, fmt.Errorf("routing.evaluate: rules must be a list, got %s", rulesVal.Type())
+		}
+
+		rules := make([]routingRule, rulesList.Len())
+		for i := 0; i < rulesList.Len(); i++ {
+			ruleDict, ok := rulesList.Index(i).(*starlark.Dict)
+			if !ok {
+				return nil, fmt.Errorf("routing.evaluate: rules[%d] must be a dict, got %s", i, rulesList.Index(i).Type())
+			}
+			m := DictToMap(ruleDict)
+
+			field, _ := m["field"].(string)
+			op, _ := m["op"].(string)
+			target, _ := m["target"].(string)
+			if field == "" || op == "" || target == "" {
+				return nil, fmt.Errorf("routing.evaluate: rules[%d] must have field, op, and target", i)
+			}
+			rules[i] = routingRule{
+				Field:  field,
+				Op:     op,
+				Value:  m["value"],
+				Target: target,
+			}
+		}
+
+		// Convert data dict → Go map
+		dataDict, ok := dataVal.(*starlark.Dict)
+		if !ok {
+			return nil, fmt.Errorf("routing.evaluate: data must be a dict, got %s", dataVal.Type())
+		}
+		data := DictToMap(dataDict)
+
+		// Evaluate rules — first match wins
+		for _, rule := range rules {
+			if evaluateRoutingCondition(rule, data) {
+				return starlark.String(rule.Target), nil
+			}
+		}
+
+		return starlark.None, nil
+	}
+}
+
+// ── Evaluation helpers (mirrored from workflow/routing.go) ─────────
+//
+// These are pure functions copied from the workflow package to avoid
+// a sandbox → workflow import cycle. The workflow package continues
+// using its own copy for ResolveNextStage.
+
+// evaluateRoutingCondition checks if a single rule matches against data.
+func evaluateRoutingCondition(rule routingRule, data map[string]any) bool {
+	val, exists := data[rule.Field]
+
+	switch rule.Op {
+	case "exists":
+		return exists
+	case "not_exists":
+		return !exists
+	}
+
+	if !exists {
+		return false
+	}
+
+	switch rule.Op {
+	case "eq":
+		return routingCompareEq(val, rule.Value)
+	case "neq":
+		return !routingCompareEq(val, rule.Value)
+	case "gt":
+		return routingCompareNum(val, rule.Value) > 0
+	case "lt":
+		return routingCompareNum(val, rule.Value) < 0
+	case "gte":
+		return routingCompareNum(val, rule.Value) >= 0
+	case "lte":
+		return routingCompareNum(val, rule.Value) <= 0
+	case "in":
+		return routingCompareIn(val, rule.Value)
+	case "contains":
+		return routingCompareContains(val, rule.Value)
+	default:
+		return false
+	}
+}
+
+func routingCompareEq(a, b any) bool {
+	return fmt.Sprintf("%v", a) == fmt.Sprintf("%v", b)
+}
+
+func routingCompareNum(a, b any) int {
+	af := routingToFloat(a)
+	bf := routingToFloat(b)
+	if af == nil || bf == nil {
+		return 0
+	}
+	switch {
+	case *af < *bf:
+		return -1
+	case *af > *bf:
+		return 1
+	default:
+		return 0
+	}
+}
+
+func routingToFloat(v any) *float64 {
+	switch n := v.(type) {
+	case float64:
+		return &n
+	case int:
+		f := float64(n)
+		return &f
+	case int64:
+		f := float64(n)
+		return &f
+	case string:
+		var f float64
+		if _, err := fmt.Sscanf(n, "%f", &f); err == nil {
+			return &f
+		}
+	}
+	return nil
+}
+
+func routingCompareIn(val, list any) bool {
+	arr, ok := list.([]any)
+	if !ok {
+		return false
+	}
+	vs := fmt.Sprintf("%v", val)
+	for _, item := range arr {
+		if fmt.Sprintf("%v", item) == vs {
+			return true
+		}
+	}
+	return false
+}
+
+func routingCompareContains(val, target any) bool {
+	s := fmt.Sprintf("%v", val)
+	t := fmt.Sprintf("%v", target)
+	return strings.Contains(s, t)
+}

server/sandbox/routing_module_test.go

@@ -0,0 +1,162 @@
+package sandbox
+
+import (
+	"testing"
+
+	"go.starlark.net/starlark"
+)
+
+func runRoutingScript(t *testing.T, script string) starlark.StringDict {
+	t.Helper()
+	mod := BuildRoutingModule()
+	predeclared := starlark.StringDict{"routing": mod}
+	globals, err := starlark.ExecFile(&starlark.Thread{Name: "test"}, "test.star", script, predeclared)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return globals
+}
+
+func runRoutingScriptErr(t *testing.T, script string) error {
+	t.Helper()
+	mod := BuildRoutingModule()
+	predeclared := starlark.StringDict{"routing": mod}
+	_, err := starlark.ExecFile(&starlark.Thread{Name: "test"}, "test.star", script, predeclared)
+	return err
+}
+
+func TestRoutingEvaluate_SingleMatch(t *testing.T) {
+	globals := runRoutingScript(t, `
+result = routing.evaluate([
+    {"field": "priority", "op": "eq", "value": "high", "target": "escalation"},
+], {"priority": "high"})
+`)
+	result := globals["result"]
+	if s, ok := result.(starlark.String); !ok || string(s) != "escalation" {
+		t.Fatalf("expected 'escalation', got %v", result)
+	}
+}
+
+func TestRoutingEvaluate_FirstMatchWins(t *testing.T) {
+	globals := runRoutingScript(t, `
+result = routing.evaluate([
+    {"field": "amount", "op": "gt", "value": 100, "target": "big"},
+    {"field": "amount", "op": "gt", "value": 50,  "target": "medium"},
+], {"amount": 200})
+`)
+	result := globals["result"]
+	if s, ok := result.(starlark.String); !ok || string(s) != "big" {
+		t.Fatalf("expected 'big', got %v", result)
+	}
+}
+
+func TestRoutingEvaluate_NoMatch(t *testing.T) {
+	globals := runRoutingScript(t, `
+result = routing.evaluate([
+    {"field": "status", "op": "eq", "value": "done", "target": "finish"},
+], {"status": "pending"})
+`)
+	if globals["result"] != starlark.None {
+		t.Fatalf("expected None, got %v", globals["result"])
+	}
+}
+
+func TestRoutingEvaluate_EmptyRules(t *testing.T) {
+	globals := runRoutingScript(t, `
+result = routing.evaluate([], {"x": 1})
+`)
+	if globals["result"] != starlark.None {
+		t.Fatalf("expected None, got %v", globals["result"])
+	}
+}
+
+func TestRoutingEvaluate_AllOperators(t *testing.T) {
+	globals := runRoutingScript(t, `
+# exists
+r1 = routing.evaluate([{"field": "x", "op": "exists", "value": "", "target": "yes"}], {"x": 1})
+# not_exists
+r2 = routing.evaluate([{"field": "x", "op": "not_exists", "value": "", "target": "yes"}], {"y": 1})
+# eq
+r3 = routing.evaluate([{"field": "s", "op": "eq", "value": "abc", "target": "yes"}], {"s": "abc"})
+# neq
+r4 = routing.evaluate([{"field": "s", "op": "neq", "value": "abc", "target": "yes"}], {"s": "xyz"})
+# gt
+r5 = routing.evaluate([{"field": "n", "op": "gt", "value": 10, "target": "yes"}], {"n": 20})
+# lt
+r6 = routing.evaluate([{"field": "n", "op": "lt", "value": 10, "target": "yes"}], {"n": 5})
+# gte
+r7 = routing.evaluate([{"field": "n", "op": "gte", "value": 10, "target": "yes"}], {"n": 10})
+# lte
+r8 = routing.evaluate([{"field": "n", "op": "lte", "value": 10, "target": "yes"}], {"n": 10})
+# in
+r9 = routing.evaluate([{"field": "s", "op": "in", "value": ["a", "b", "c"], "target": "yes"}], {"s": "b"})
+# contains
+r10 = routing.evaluate([{"field": "s", "op": "contains", "value": "ell", "target": "yes"}], {"s": "hello"})
+`)
+	for _, name := range []string{"r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10"} {
+		v := globals[name]
+		if s, ok := v.(starlark.String); !ok || string(s) != "yes" {
+			t.Errorf("%s: expected 'yes', got %v", name, v)
+		}
+	}
+}
+
+func TestRoutingEvaluate_TypeCoercion(t *testing.T) {
+	globals := runRoutingScript(t, `
+# Numeric string vs int
+r1 = routing.evaluate([
+    {"field": "n", "op": "gt", "value": 10, "target": "yes"},
+], {"n": "20"})
+
+# Int equality via string normalization
+r2 = routing.evaluate([
+    {"field": "n", "op": "eq", "value": 42, "target": "yes"},
+], {"n": 42})
+`)
+	for _, name := range []string{"r1", "r2"} {
+		v := globals[name]
+		if s, ok := v.(starlark.String); !ok || string(s) != "yes" {
+			t.Errorf("%s: expected 'yes', got %v", name, v)
+		}
+	}
+}
+
+func TestRoutingEvaluate_BadInput(t *testing.T) {
+	// rules must be a list
+	err1 := runRoutingScriptErr(t, `routing.evaluate("bad", {})`)
+	if err1 == nil {
+		t.Fatal("expected error for non-list rules")
+	}
+
+	// data must be a dict
+	err2 := runRoutingScriptErr(t, `routing.evaluate([], "bad")`)
+	if err2 == nil {
+		t.Fatal("expected error for non-dict data")
+	}
+
+	// rule missing required fields
+	err3 := runRoutingScriptErr(t, `routing.evaluate([{"field": "x"}], {})`)
+	if err3 == nil {
+		t.Fatal("expected error for incomplete rule")
+	}
+}
+
+func TestRoutingEvaluate_MissingFields(t *testing.T) {
+	globals := runRoutingScript(t, `
+# Field not in data — eq should not match
+r1 = routing.evaluate([
+    {"field": "absent", "op": "eq", "value": "x", "target": "bad"},
+], {"other": "y"})
+
+# not_exists matches when field is absent
+r2 = routing.evaluate([
+    {"field": "absent", "op": "not_exists", "value": "", "target": "good"},
+], {"other": "y"})
+`)
+	if globals["r1"] != starlark.None {
+		t.Fatalf("r1: expected None for missing field, got %v", globals["r1"])
+	}
+	if s, ok := globals["r2"].(starlark.String); !ok || string(s) != "good" {
+		t.Fatalf("r2: expected 'good', got %v", globals["r2"])
+	}
+}

server/sandbox/runner.go

@@ -467,6 +467,9 @@ func (r *Runner) buildModulesWithLibCtx(ctx context.Context, packageID string, m
 	// Always available — read-only team role queries
 	modules["teams"] = BuildTeamsModule(ctx, r.stores)
 
+	// Always available — pure-computation routing decision engine
+	modules["routing"] = BuildRoutingModule()
+
 	// Allows any starlark package to load declared library dependencies.
 	if lc != nil {
 		modules["lib"] = BuildLibModule(ctx, r, packageID, rc, lc)