feat: SpeckDL v0.2-DP spec with dark provenance primitives

New language members: provenance, review, derives, satisfies, author, source

- provenance block: declare intent sources (regulation, design_decision, parent_spec, external_doc)
- review directive: mark verification boundaries (manual, auto, hybrid)
- derives/satisfies: spec-to-spec and spec-to-requirement edges
- author/source: who wrote it and what drove it
- Provenance-aware event semantics: runtime events trace back to intent
- Updated EBNF grammar, semantics, examples, and JSON-LD mapping
- Three new examples: regulated medical device, auto-verified service, compliance audit trail
- All primitives optional — Specks without provenance still compile fine
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# SpeckDL Language Specification v0.2-DP
> The specification-first language for auditable software.
> **This version adds Dark Provenance primitives: `provenance`, `review`, `derives`, `satisfies`, `author`, `source`.**
> Part of the [Speckl](https://os.scoble.me/forgejo/sscoble/speckl) project. MIT License.
---
## 1. Introduction
SpeckDL is a domain-specific language for defining system behavior and interfaces. A SpeckDL specification (a **Speck**) describes *what* a system should do, not *how* it should do it. Specks compile through a deterministic pipeline — SpeckDL → Z3 → DST → WASM — producing verified artifacts with full dark provenance.
### Design Goals
- **Human-readable first.** A Speck should be understandable by a domain expert who doesn't write code.
- **Machine-verifiable.** Every constraint in a Speck compiles to Z3 (SMT solver) input. Verification is automatic.
- **Provenance-native.** The compilation pipeline records derivation edges automatically. Provenance is not bolted on — it's structural.
- **Composable.** Specks compose via interfaces. Large systems are built from small, verified Specks.
- **Deterministic.** Same input, same output. No LLMs in the compilation path.
---
## 2. Syntax
### 2.1 Top-Level Structure
A SpeckDL file consists of one or more Speck definitions:
```
speck <Name> {
<members>
}
```
Members are drawn from: `input`, `output`, `constraint`, `verify`, `interface`, `import`, `event`, and **Dark Provenance primitives**: `provenance`, `review`, `derives`, `satisfies`, `author`, `source`.
### 2.2 EBNF Grammar
```ebnf
file = { speck_def | import_stmt }
speck_def = "speck" IDENT "{" { member } "}"
member = input_def | output_def | constraint_def
| verify_def | interface_def | event_def
| provenance_def | review_def | derives_def
| satisfies_def | author_def | source_def
input_def = "input" ":" type_expr
output_def = "output" ":" type_expr
type_expr = primitive | compound | IDENT
primitive = "Nat" | "Int" | "Real" | "Bool" | "String" | "Bytes"
compound = "{" { IDENT ":" type_expr [","] } "}"
| "[" type_expr "]"
constraint_def = "constraint" ":" expr
verify_def = "verify" ":" temporal_expr
expr = literal | IDENT | expr op expr | expr "." IDENT
| func_call | "(" expr ")"
op = "==" | "!=" | "<=" | ">=" | "<" | ">"
| "+" | "-" | "*" | "/" | "mod"
| "and" | "or" | "not" | "implies"
func_call = IDENT "(" [expr { "," expr }] ")"
temporal_expr = "always" "(" expr ")"
| "eventually" "(" expr ")"
| "implies" "(" expr "," expr ")"
interface_def = "interface" IDENT "{" { method_sig } "}"
method_sig = IDENT "(" [ { IDENT ":" type_expr "," } ] ")" ":" type_expr
event_def = "event" IDENT "{" { IDENT ":" type_expr [","] } "}"
provenance_def = "provenance" "{" { provenance_clause } "}"
provenance_clause = "regulation" ":" STRING
| "design_decision" ":" STRING
| "parent_spec" ":" IDENT
| "external_doc" ":" STRING [ "at" STRING ]
review_def = "review" ":" review_kind
review_kind = "manual" | "auto" | "hybrid"
derives_def = "derives" "from" IDENT [ "via" STRING ]
satisfies_def = "satisfies" IDENT [ "clause" STRING ]
author_def = "author" ":" STRING [ "<" STRING ">" ]
source_def = "source" ":" source_kind [ "ref" STRING ]
source_kind = "conversation" | "meeting" | "document" | "regulation"
| "architecture_review" | "threat_model" | "compliance_audit"
import_stmt = "import" STRING ["as" IDENT]
literal = NAT_LIT | INT_LIT | REAL_LIT | BOOL_LIT | STRING_LIT
IDENT = letter { letter | digit | "_" }
```
### 2.3 Type System
| Type | Meaning | Z3 Mapping |
|------|---------|------------|
| `Nat` | Non-negative integer | `Int` with constraint `>= 0` |
| `Int` | Signed integer | `Int` |
| `Real` | Real number | `Real` |
| `Bool` | Boolean | `Bool` |
| `String` | UTF-8 string | Uninterpreted sort |
| `Bytes` | Byte sequence | Uninterpreted sort |
| `{ ... }` | Record/tuple | Datatype |
| `[T]` | List of T | Seq(T) |
---
## 3. Semantics
### 3.1 Speck Definitions
A Speck defines a behavioral unit with:
- **Inputs:** Typed parameters the Speck accepts.
- **Outputs:** Typed results the Speck produces.
- **Constraints:** Invariants that must hold for all valid inputs and outputs.
- **Verification conditions:** Temporal properties that the Z3 solver must prove.
A Speck is *well-formed* if:
1. All referenced identifiers are in scope.
2. No two constraints are contradictory (Z3 must report SAT for the conjunction of all constraints).
3. All verification conditions are provable from the constraints.
### 3.2 Constraint Semantics
A `constraint` defines an invariant that must hold across all valid executions of the Speck. Constraints are compiled to Z3 assertions:
```
constraint: maxRetries <= 5
```
becomes:
```smt2
(assert (<= maxRetries 5))
```
Constraints are **universally quantified** over all inputs unless explicitly scoped.
### 3.3 Verification Semantics
A `verify` clause defines a property that must be provable from the Speck's constraints:
```
verify: always(implies(attempt > 1, delay > 0))
```
becomes:
```smt2
(assert (=> (> attempt 1) (> delay 0)))
(check-sat)
```
If Z3 returns `UNSAT` when asked to negate a verification condition, the condition is proven. If Z3 returns `SAT`, the Speck contains a counterexample — it can be violated.
### 3.4 Interface Semantics
An interface defines a contract between Specks. A Speck that provides an interface must satisfy all constraints of that interface:
```
interface PaymentProcessor {
charge(amount: Real, currency: String): Result
refund(transactionId: Nat): Result
}
speck StripeProcessor {
interface: PaymentProcessor
input: { apiKey: String }
output: Result
constraint: amount > 0
constraint: currency in ["USD", "EUR", "GBP"]
}
```
### 3.5 Event Semantics
Events define state transitions that the provenance graph records:
```
event RetryAttempted {
attemptNumber: Nat
delay: Real
remainingRetries: Nat
}
```
Events are emitted during execution and recorded as nodes in the provenance graph. They do not affect the verification pipeline — they exist for observability.
---
## 3.6 Dark Provenance Semantics (NEW)
Dark Provenance primitives make intent sources and verification boundaries explicit in the specification language. They compile to JSON-LD provenance graph nodes and edges.
### 3.6.1 `provenance` Block Semantics
The `provenance` block declares where a Speck's intent originates:
| Clause | Meaning | JSON-LD Output |
|--------|---------|----------------|
| `regulation: "DO-178C"` | Compliance requirement | `prov:wasInformedBy` → Regulation node |
| `design_decision: "ADR-0017"` | Architecture decision record | `prov:wasDerivedFrom` → Decision node |
| `parent_spec: ParentSpeck` | Decomposition from another Speck | `prov:wasDerivedFrom` → Parent Speck node |
| `external_doc: "RFC 8446" at "https://..."` | External reference | `prov:wasInformedBy` → Document node |
Multiple clauses may appear; each creates a separate provenance edge.
### 3.6.2 `review` Directive Semantics
The `review` directive marks verification boundaries:
- `review: manual` — Requires human sign-off before deployment. Compiler emits a `ManualReviewRequired` node in the provenance graph.
- `review: auto` — Fully automated verification. No human gate required.
- `review: hybrid` — Automated verification with spot-check sampling. Compiler emits sampling parameters.
Review status is checked at compile time; `manual` Specks without sign-off block the pipeline.
### 3.6.3 `derives` / `satisfies` Semantics
These primitives create explicit edges in the provenance graph:
**`derives from SpecName via "rationale"`**
- Creates a `prov:wasDerivedFrom` edge from the current Speck to `SpecName`
- Optional `via` clause records the derivation rationale as `rdfs:comment`
- Used for: refactoring, decomposition, specialization
**`satisfies RequirementId clause "3.2.1"`**
- Creates a `speckl:satisfies` edge to a requirement node
- Optional `clause` specifies the exact subsection
- Used for: tracing to regulatory requirements, user stories, specs
### 3.6.4 `author` / `source` Metadata Semantics
These primitives capture "who" and "why":
**`author: "Name" <"email@example.com">`**
- Binds the Speck to an `prov:Agent` node
- Compiles to `prov:wasAttributedTo` edge
- Optional email used for agent deduplication in the provenance graph
**`source: kind ref "identifier"`**
- Records what drove the creation of this Speck
- `kind`: `conversation`, `meeting`, `document`, `regulation`, `architecture_review`, `threat_model`, `compliance_audit`
- `ref`: Optional identifier (meeting ID, document URL, ticket number)
- Compiles to `prov:wasInformedBy` → Source node with `prov:type`
### 3.6.5 Provenance-Aware Event Semantics
Events declared with the standard `event` syntax gain provenance edges automatically:
```
event DoseCalculated { volume: Real, safe: Bool }
```
When this event fires at runtime, the provenance graph records:
- The event instance node (`prov:Activity`)
- An edge to the declaring Speck (`prov:wasInformedBy`)
- An edge to the Speck's `provenance` sources (transitive intent tracing)
- An edge to the runtime WASM module that emitted it (`prov:wasGeneratedBy`)
This creates complete audit trails: Event → Speck → Intent Source → Regulatory Requirement.
## 4. Compilation Pipeline
### 4.1 Stage 1: SpeckDL → Z3
Each Speck is compiled to SMT-LIB2 format:
1. Type declarations become Z3 sort declarations.
2. Input/output declarations become Z3 constants.
3. Constraints become `assert` statements.
4. Verification conditions become `check-sat` queries.
The compiler checks for:
- **Contradictory constraints:** If the conjunction of all constraints is UNSAT, the Speck is impossible to implement.
- **Unsatisfiable verification conditions:** If a verify clause can be violated, the compiler reports the counterexample.
### 4.2 Stage 2: Z3 → DST (Decision Structures)
When Z3 reports SAT for a Speck, the model (assignment of values satisfying all constraints) is compiled into a **Decision Structure Tree**:
```
DSTNode {
condition: expr // branching predicate
if_true: DSTNode // subtree when condition holds
if_false: DSTNode // subtree when condition doesn't hold
result: value? // leaf value (if terminal)
}
```
A DST represents the complete behavioral space of a verified Speck. Every possible input maps to exactly one path through the DST, terminating at a leaf with the verified output.
### 4.3 Stage 3: DST → WASM
DSTs compile to WebAssembly via a direct translation:
- Each DST node becomes a `br_if` / `br` instruction pair.
- Leaf values become `i32.const`, `f64.const`, or structured return values.
- The resulting WASM module exports a single function matching the Speck's input/output signature.
This compilation is *semantics-preserving by construction*: the WASM module implements exactly the behaviors encoded in the DST, which represents exactly the satisfiable space of the Speck.
### 4.4 Provenance Graph Construction (UPDATED)
At each compilation stage, the pipeline records derivation edges. **Dark Provenance primitives** in the SpeckDL source generate explicit provenance nodes and edges:
```
Speck "RetryHandler"
├── compiled_to → Z3 assertion set (sha256:abc...)
├── verified_by → Z3 result: SAT
├── compiled_to → DST (sha256:def...)
├── compiled_to → WASM module (sha256:789...)
├── **provenance: {**
│ **regulation: "ISO 26262-6"**
│ **design_decision: "ADR-0042"**
│ **parent_spec: "FaultHandler"**
│ **author: "scott"**
│ **source: conversation ref "slack://C123/456"**
│ **review: manual**
│ **derives_from: "FaultHandler"**
│ **satisfies: "ASIL-D-REQ-17"**
│ **}**
├── **attributed_to → Agent("scott")**
├── **wasDerivedFrom → Speck("FaultHandler")**
├── **satisfies → Requirement("ASIL-D-REQ-17")**
├── **wasInformedBy → Regulation("ISO 26262-6")**
├── **wasInformedBy → Decision("ADR-0042")**
└── **requiresReview → ManualReviewRequired**
```
The provenance graph is serialized as JSON-LD and stored alongside the compiled artifacts.
**Dark Provenance JSON-LD Output:**
```json
{
"@context": {
"prov": "http://www.w3.org/ns/prov#",
"speckl": "https://os.scoble.me/speckl/ns#",
"rdfs": "http://www.w3.org/2000/01/rdf-schema#"
},
"@id": "speck:RetryHandler",
"@type": "speckl:Speck",
"prov:wasAttributedTo": {
"@id": "agent:scott",
"@type": "prov:Agent",
"rdfs:label": "scott"
},
"prov:wasInformedBy": [
{ "@id": "reg:ISO-26262-6", "@type": "speckl:Regulation" },
{ "@id": "decision:ADR-0042", "@type": "speckl:DesignDecision" },
{ "@id": "conv:slack-C123-456", "@type": "speckl:Conversation" }
],
"prov:wasDerivedFrom": { "@id": "speck:FaultHandler" },
"speckl:satisfies": {
"@id": "req:ASIL-D-REQ-17",
"speckl:clause": "4.3.2"
},
"speckl:reviewRequired": {
"@type": "speckl:ManualReview",
"speckl:status": "pending"
}
}
```
---
## 5. Examples
### 5.1 Simple: API Rate Limiter
```
speck RateLimiter {
input: { requests: [Request], window: Nat, maxRequests: Nat }
output: { allowed: [Bool], remaining: Nat }
constraint: maxRequests > 0
constraint: window > 0
constraint: count(allowed, true) <= maxRequests
constraint: remaining == maxRequests - count(allowed, true)
verify: always(implies(remaining == 0, not(allowed[current])))
}
```
### 5.2 Medium: Data Pipeline with Constraints
```
speck ETLTransform {
input: { source: DataSource, schema: Schema, dedup: Bool }
output: { result: Dataset, rejected: Nat }
constraint: result.schema == schema
constraint: rejected >= 0
constraint: implies(dedup, count(result) <= count(source))
constraint: implies(not dedup, count(result) == count(source))
verify: always(implies(dedup, no_duplicates(result)))
}
```
### 5.3 Complex: Regulated Medical Device Function
```
speck DrugDosageCalculator {
input: {
patientWeight: Real,
drugConcentration: Real,
prescribedDose: Real,
minDose: Real,
maxDose: Real,
frequency: Nat
}
output: {
volume: Real,
safe: Bool
}
constraint: patientWeight > 0
constraint: drugConcentration > 0
constraint: minDose > 0
constraint: maxDose > minDose
constraint: frequency >= 1
constraint: frequency <= 6
constraint: implies(safe, volume >= minDose / drugConcentration)
constraint: implies(safe, volume <= maxDose / drugConcentration)
constraint: implies(not safe, volume == 0)
verify: always(implies(
prescribedDose >= minDose and prescribedDose <= maxDose,
safe
))
verify: always(implies(not safe, volume == 0))
event DoseCalculated { volume: Real, safe: Bool }
event DoseRejected { reason: String }
}
```
### 5.4 Edge: Self-Referential Spec
```
speck SpeckValidator {
input: { spec: SpeckDefinition, references: [SpeckDefinition] }
output: { valid: Bool, errors: [String] }
constraint: implies(valid, count(errors) == 0)
constraint: implies(not valid, count(errors) > 0)
constraint: forall(ref in references, ref.is_well_formed)
verify: always(implies(
spec.is_well_formed and forall(r in references, r.is_well_formed),
valid
))
}
```
### 5.5 Composed: Multi-Speck System
```
speck PaymentService {
import "rate-limiter.speck" as limiter
import "retry-handler.speck" as retry
input: { payment: Payment, apiKey: String }
output: Result
constraint: limiter.maxRequests == 100
constraint: limiter.window == 60
constraint: retry.maxRetries == 3
constraint: implies(not limiter.allowed, output == RateLimited)
constraint: implies(limiter.allowed, output in [Success, Failed, RetryExhausted])
verify: always(implies(
limiter.remaining == 0,
output == RateLimited
))
}
```
### 5.6 Dark Provenance: Regulated Medical Device (NEW)
This example demonstrates all Dark Provenance primitives in a safety-critical context:
```
speck InfusionPumpController {
// Intent sources
provenance {
regulation: "FDA 21 CFR 820.30"
regulation: "IEC 62304 Class C"
design_decision: "ADR-0023 Infusion Safety Architecture"
external_doc: "AAMI TIR32" at "https://www.aami.org/tir32"
}
// Traceability to system requirements
satisfies SYS-REQ-042
satisfies SYS-REQ-043 clause "5.2.1"
// Authorship and origin
author: "Dr. Sarah Chen" <"s.chen@meddevice.example">
source: architecture_review ref "AR-2024-0315"
// Verification boundary
review: manual
// Parent spec relationship
derives from SafetyCriticalController via "decomposition of dosing logic"
input: {
prescribedRate: Real,
vtbi: Real, // Volume to be infused
drugLibraryEntry: DrugProfile,
patientWeight: Real,
airInLineSensor: Bool
}
output: {
motorSpeed: Real,
occlusionAlarm: Bool,
airInLineAlarm: Bool,
complete: Bool
}
// Safety constraints
constraint: prescribedRate > 0
constraint: prescribedRate <= drugLibraryEntry.maxRate
constraint: vtbi > 0
constraint: patientWeight > 0
constraint: implies(airInLineSensor, motorSpeed == 0)
constraint: implies(occlusionAlarm, motorSpeed == 0)
// Therapeutic constraint: dose must match prescription
constraint: motorSpeed == prescribedRate * drugLibraryEntry.conversionFactor
verify: always(implies(
airInLineSensor or occlusionAlarm,
motorSpeed == 0
))
verify: always(implies(
complete,
vtbi == 0
))
event DoseStarted {
rate: Real
remainingVolume: Real
timestamp: Nat
}
event AlarmTriggered {
alarmType: String
severity: Nat
automaticResponse: String
}
event InfusionComplete {
totalVolumeDelivered: Real
duration: Real
}
}
```
### 5.7 Dark Provenance: Auto-Verified Service (NEW)
This example shows `review: auto` for internal services with no manual gate:
```
speck InternalMetricsCollector {
provenance {
parent_spec: ObservabilityPlatform
design_decision: "ADR-0056 Unified Telemetry"
}
author: "Platform Team" <"platform@example.com">
source: meeting ref "zoom://2024-04-15/platform-sync"
satisfies PLATFORM-REQ-12
derives from ObservabilityPlatform via "metrics ingestion path"
review: auto
input: {
serviceName: String,
metricBatch: [Metric],
apiKey: String
}
output: { accepted: Nat, rejected: Nat, latencyMs: Nat }
constraint: count(metricBatch) <= 1000
constraint: accepted + rejected == count(metricBatch)
constraint: latencyMs <= 100
verify: always(implies(
count(metricBatch) > 0,
accepted + rejected == count(metricBatch)
))
}
```
### 5.8 Dark Provenance: Compliance Audit Trail (NEW)
This example demonstrates provenance for audit and compliance scenarios:
```
speck AuditLogValidator {
provenance {
regulation: "SOX Section 404"
regulation: "PCI-DSS v4.0 Requirement 10"
}
author: "Compliance Engineering"
source: compliance_audit ref "AUDIT-2024-Q1"
satisfies COMPLIANCE-REQ-08 clause "10.3"
review: hybrid
input: {
logEntry: LogEntry,
previousHash: String,
validatorKeys: [String]
}
output: { valid: Bool, tamperDetected: Bool, newHash: String }
constraint: implies(tamperDetected, not valid)
constraint: newHash == hash(logEntry, previousHash)
constraint: implies(valid, signatureValid(logEntry, validatorKeys))
verify: always(implies(
logEntry.hash != hash(logEntry.payload),
tamperDetected
))
event IntegrityCheckFailed {
logId: String
expectedHash: String
actualHash: String
severity: Nat
}
}
```
---
## 6. Tooling
### Reference Compiler
The reference compiler (`speckl-compile`) is a Node.js/TypeScript application that:
1. Parses SpeckDL files into an AST.
2. Type-checks the AST against the type system defined in §3.
3. Compiles constraints and verification conditions to SMT-LIB2.
4. Invokes Z3 and interprets results.
5. Compiles verified models to DSTs.
6. Compiles DSTs to WASM.
7. Emits provenance graph metadata (JSON-LD) at each stage.
### Planned Tooling
| Tool | Purpose | Status |
|------|---------|--------|
| `speckl-compile` | Reference compiler | Spec only |
| `speckl-lsp` | Language Server Protocol (IDE support) | Planned |
| `speckl-playground` | Browser-based spec editor + live verification | Planned |
| `speckl-fmt` | Formatter | Planned |
| `speckl-doc` | Documentation generator from Specks | Planned |
---
## Appendix A: Z3 Mapping Reference
| SpeckDL Construct | SMT-LIB2 |
|---|---|
| `Nat n` | `(declare-const n Int)` + `(assert (>= n 0))` |
| `Int n` | `(declare-const n Int)` |
| `Real r` | `(declare-const r Real)` |
| `Bool b` | `(declare-const b Bool)` |
| `constraint: e` | `(assert e)` |
| `verify: always(e)` | `(assert (not e))` + `(check-sat)` — expect UNSAT |
| `verify: eventually(e)` | Not directly expressible; requires bounded model checking |
| `a == b` | `(= a b)` |
| `a implies b` | `(=> a b)` |
| `a and b` | `(and a b)` |
| `forall(x in S, e)` | `(forall ((x T)) (=> (member x S) e))` |
## Appendix B: Dark Provenance JSON-LD Reference (NEW)
| SpeckDL Primitive | JSON-LD Output | PROV-O Mapping |
|---|---|---|
| `provenance { regulation: X }` | Node with `prov:wasInformedBy` → Regulation | `prov:Entity` → `prov:Activity` |
| `provenance { design_decision: X }` | Node with `prov:wasInformedBy` → Decision | `prov:Entity` → `prov:Activity` |
| `provenance { parent_spec: X }` | Node with `prov:wasDerivedFrom` → Speck | `prov:Entity` → `prov:Entity` |
| `provenance { external_doc: X at Y }` | Node with `prov:wasInformedBy` → Document | `prov:Entity` → `prov:Activity` |
| `author: Name <email>` | Agent node + `prov:wasAttributedTo` | `prov:Agent` |
| `source: kind ref X` | Source node + `prov:wasInformedBy` | `prov:Activity` with `prov:type` |
| `derives from X via Y` | `prov:wasDerivedFrom` edge | `prov:wasDerivedFrom` |
| `satisfies X clause Y` | `speckl:satisfies` edge + clause property | Extension property |
| `review: manual` | `speckl:ManualReview` requirement node | Extension |
| `review: auto` | No additional nodes (default path) | N/A |
| `review: hybrid` | `speckl:HybridReview` with sampling params | Extension |
---
*This is a v0.2-DP specification. Dark Provenance primitives are optional but recommended for safety-critical and regulated systems. Feedback welcome via the [Speckl repository](https://os.scoble.me/forgejo/sscoble/speckl).*