# CONTRACT-API-GOVERNANCE-BASELINE-012: Aggregate OpenAPI Spec & SDK Generation

> **Status:** Published
> **Version:** 1.0.0
> **Published:** 2025-12-05
> **Owners:** API Governance Guild, SDK Generator Guild
> **Unblocks:** SDKGEN-63-001, SDKGEN-63-002, SDKGEN-63-003, SDKGEN-63-004, SDKGEN-64-001, SDKGEN-64-002

## Overview

This contract defines the aggregate OpenAPI specification freeze process, versioning rules, and SHA256 commitment mechanism that enables deterministic SDK generation across TypeScript, Python, Go, and Java targets.

## Aggregate Specification

### Source Location

```
src/Api/StellaOps.Api.OpenApi/stella.yaml
```

### Composition Process

The aggregate spec is generated by `compose.mjs` from per-service specs:

| Service | Source Spec | Tag Prefix |
|---------|-------------|------------|
| Authority | `authority/openapi.yaml` | `authority.*` |
| Export Center | `export-center/openapi.yaml` | `export.*` |
| Graph | `graph/openapi.yaml` | `graph.*` |
| Orchestrator | `orchestrator/openapi.yaml` | `orchestrator.*` |
| Policy | `policy/openapi.yaml` | `policy.*` |
| Scheduler | `scheduler/openapi.yaml` | `scheduler.*` |

### Current Version

```yaml
openapi: 3.1.0
info:
  title: StellaOps Aggregate API
  version: 0.0.1
```

---

## Freeze Process

### 1. Version Tagging

When freezing for SDK generation:

```bash
# Compute SHA256 of aggregate spec
sha256sum src/Api/StellaOps.Api.OpenApi/stella.yaml > stella.yaml.sha256

# Tag the commit
git tag -a api/v0.1.0-alpha -m "API freeze for SDK Wave B generation"
```

### 2. SHA256 Commitment

SDK generators must validate the spec hash before generation:

```bash
# Environment variable for hash guard
export STELLA_OAS_EXPECTED_SHA256="<sha256-hash>"

# Generator validates before running
if [ "$(sha256sum stella.yaml | cut -d' ' -f1)" != "$STELLA_OAS_EXPECTED_SHA256" ]; then
  echo "ERROR: Spec hash mismatch - regenerate after spec freeze"
  exit 1
fi
```

### 3. Published Artifacts

On freeze, publish:

| Artifact | Location | Purpose |
|----------|----------|---------|
| Tagged spec | `api/v{version}` git tag | Version reference |
| SHA256 file | `stella.yaml.sha256` | Hash verification |
| Changelog | `CHANGELOG-api.md` | Breaking changes |

---

## SDK Generation Contract

### Generator Configuration

| Language | Config | Output |
|----------|--------|--------|
| TypeScript | `ts/config.yaml` | ESM/CJS with typed errors |
| Python | `python/config.yaml` | sync/async clients, type hints |
| Go | `go/config.yaml` | context-first API |
| Java | `java/config.yaml` | builder pattern, OkHttp |

### Toolchain Lock

```yaml
# toolchain.lock.yaml
openapi-generator-cli: 7.4.0
jdk: 21.0.1
node: 22.x
python: 3.11+
go: 1.21+
```

### Hash Guard Implementation

Each generator emits `.oas.sha256` for provenance:

```bash
# Example: TypeScript generation
echo "$STELLA_OAS_EXPECTED_SHA256  stella.yaml" > dist/.oas.sha256
```

---

## Versioning Rules

### Semantic Versioning

```
MAJOR.MINOR.PATCH[-PRERELEASE]

- MAJOR: Breaking API changes
- MINOR: New endpoints/fields (backwards compatible)
- PATCH: Bug fixes, documentation
- PRERELEASE: alpha, beta, rc
```

### Breaking Change Detection

```bash
# Run API compatibility check
npm run api:compat -- --old scripts/__fixtures__/api-compat/old.yaml \
                      --new src/Api/StellaOps.Api.OpenApi/stella.yaml
```

### Version Matrix

| API Version | SDK Versions | Status |
|-------------|--------------|--------|
| 0.0.1 | - | Current (unfrozen) |
| 0.1.0-alpha | TS/Py/Go/Java alpha | Target freeze |

---

## Freeze Checklist

Before SDK generation can proceed:

- [ ] All per-service specs pass `npm run api:lint`
- [ ] Aggregate composition succeeds (`node compose.mjs`)
- [ ] Breaking change review completed
- [ ] SHA256 computed and committed
- [ ] Git tag created (`api/v{version}`)
- [ ] Changelog entry added
- [ ] SDK generator configs updated with hash

---

## Current Freeze Status

### Pending Actions

| Action | Owner | Due | Status |
|--------|-------|-----|--------|
| Compute SHA256 for stella.yaml | API Governance Guild | 2025-12-06 | TODO |
| Create api/v0.1.0-alpha tag | API Governance Guild | 2025-12-06 | TODO |
| Update SDKGEN configs with hash | SDK Generator Guild | 2025-12-06 | TODO |

### Immediate Unblock Path

To immediately unblock SDK generation:

```bash
# 1. Compute current spec hash
cd src/Api/StellaOps.Api.OpenApi
SHA=$(sha256sum stella.yaml | cut -d' ' -f1)
echo "Current SHA256: $SHA"

# 2. Create hash file
echo "$SHA  stella.yaml" > stella.yaml.sha256

# 3. Tag for SDK generation
git add stella.yaml.sha256
git commit -m "chore(api): freeze aggregate spec for SDK Wave B"
git tag -a api/v0.1.0-alpha -m "API freeze for SDK generation"

# 4. Set environment for generators
export STELLA_OAS_EXPECTED_SHA256="$SHA"
```

---

## SDK Generation Commands

Once freeze is complete:

```bash
# TypeScript
cd src/Sdk/StellaOps.Sdk.Generator/ts
./generate-ts.sh

# Python
cd ../python
./generate-python.sh

# Go
cd ../go
./generate-go.sh

# Java
cd ../java
./generate-java.sh

# Run all smoke tests
npm run sdk:smoke
```

---

## Governance

### Change Process

1. **Propose:** Open PR with spec changes
2. **Review:** API Governance Guild reviews for breaking changes
3. **Test:** Run `api:lint` and `api:compat`
4. **Merge:** Merge to main
5. **Freeze:** Tag and compute SHA256 when ready for SDK

### Stakeholders

- **API Governance Guild:** Spec ownership, breaking change review
- **SDK Generator Guild:** Generation toolchain, language packs
- **Platform Security:** Signing key provisioning (SDKREL-63-001)

---

## Signing Keys

### Development Key (Available Now)

A development signing key is available for staging/testing:

| File | Purpose |
|------|---------|
| `tools/cosign/cosign.dev.key` | Private key (password: `stellaops-dev`) |
| `tools/cosign/cosign.dev.pub` | Public key for verification |

**Usage for SDK staging:**
```bash
# Set environment for SDK signing
export COSIGN_KEY_FILE=tools/cosign/cosign.dev.key
export COSIGN_PASSWORD=stellaops-dev
export COSIGN_ALLOW_DEV_KEY=1

# Or use CI workflow with allow_dev_key=1
```

### Production Keys (Pending)

Production signing requires:
- Sovereign crypto key provisioning (Action #7)
- `COSIGN_PRIVATE_KEY_B64` CI secret
- Optional `COSIGN_PASSWORD` for encrypted keys

### Key Resolution Order

1. `COSIGN_KEY_FILE` environment variable
2. `COSIGN_PRIVATE_KEY_B64` (decoded to temp file)
3. `tools/cosign/cosign.key` (production drop-in)
4. `tools/cosign/cosign.dev.key` (only if `COSIGN_ALLOW_DEV_KEY=1`)

---

## Reference

- Aggregate spec: `src/Api/StellaOps.Api.OpenApi/stella.yaml`
- Composition script: `src/Api/StellaOps.Api.OpenApi/compose.mjs`
- Toolchain lock: `src/Sdk/StellaOps.Sdk.Generator/TOOLCHAIN.md`
- SDK generators: `src/Sdk/StellaOps.Sdk.Generator/{ts,python,go,java}/`

---

## Changelog

| Version | Date | Author | Changes |
|---------|------|--------|---------|
| 1.0.0 | 2025-12-05 | API Governance Guild | Initial contract |