feat: fastapi-gsap — lightweight GSAP broker PoC

Reference implementation of GCAP-SPEC-SHELLBOUND-BROKER-0001
in FastAPI. Designed for ISVs and enterprises implementing
the governed shell authorization protocol.

Architecture:
  FastAPI + SQLModel + Pydantic + async SQLite
  Single container deployment: Dockerfile included
  OpenAPI schema at /docs is the machine-readable GSAP contract

Broker Interface (§5):
  POST   /governance/authorize/     — Issue AC
  GET    /governance/authorize/{p}/ — Poll elevation
  POST   /governance/complete/      — Receive CR
  GET    /governance/session/{id}/  — View chain of custody
  POST   /governance/elevate/       — JIT elevation
  GET    /governance/drivers/       — List drivers

Identity Driver Interface (§2.2):
  IdentityDriver — abstract base (ISV extension point)
  KeycloakDriver — Keycloak implementation
  DriverRegistry — driver lookup and registration

Chronicle integration (§1.4):
  Optional CloudEvents emission via CHRONICLE_WEBHOOK_URL
  Forgejo push event format for receiver compatibility

Models:
  Pydantic schemas for AC, CR, Principal, Accord, Operation
  SQLModel DB models for persistence

Tests: 6 async tests including full AC→CR cycle

695 lines across 27 files.

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

.gitignore

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+__pycache__/
+*.pyc
+*.db
+.env
+dist/
+*.egg-info/
+.ruff_cache/
+.pytest_cache/

Dockerfile

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+FROM python:3.12-slim
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+COPY . .
+EXPOSE 8000
+CMD ["uvicorn", "gsap_broker.app:app", "--host", "0.0.0.0", "--port", "8000"]

gsap_broker/app.py

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+"""fastapi-gsap: Lightweight GSAP broker — GCAP-SPEC-SHELLBOUND-BROKER-0001."""
+import structlog
+from contextlib import asynccontextmanager
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from gsap_broker.settings import settings
+from gsap_broker.db import init_db
+from gsap_broker.routers import authorize, complete, session, elevate, health, drivers
+
+logger = structlog.get_logger()
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    await init_db()
+    logger.info("fastapi-gsap started", broker_did=settings.broker_did)
+    yield
+
+app = FastAPI(title="fastapi-gsap", description="GSAP broker PoC — GCAP-SPEC-SHELLBOUND-BROKER-0001",
+              version="0.1.0", lifespan=lifespan)
+app.add_middleware(CORSMiddleware, allow_origins=settings.cors_origins, allow_credentials=True,
+                   allow_methods=["*"], allow_headers=["*"])
+app.include_router(authorize.router, prefix="/governance", tags=["AC"])
+app.include_router(complete.router, prefix="/governance", tags=["CR"])
+app.include_router(session.router, prefix="/governance", tags=["Session"])
+app.include_router(elevate.router, prefix="/governance", tags=["Elevation"])
+app.include_router(drivers.router, prefix="/governance", tags=["Drivers"])
+app.include_router(health.router, tags=["Health"])

gsap_broker/chronicle/__init__.py

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+from .client import emit

gsap_broker/chronicle/client.py

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+"""Chronicle CloudEvents client. Optional per GSAP §1.4."""
+import hashlib, json, logging
+from datetime import datetime, UTC
+import httpx
+from gsap_broker.settings import settings
+
+logger = logging.getLogger(__name__)
+
+async def emit(kind: str, payload: dict) -> str:
+    url = settings.chronicle_webhook_url
+    if not url:
+        return ""
+    try:
+        event_json = json.dumps({"kind": kind, **payload}, sort_keys=True, default=str)
+        cid = "sha256:" + hashlib.sha256(event_json.encode()).hexdigest()
+        async with httpx.AsyncClient(timeout=5.0) as client:
+            await client.post(url, json={
+                "pusher": {"login": payload.get("principal_did", settings.broker_did)},
+                "ref": f"refs/gsap/{kind}",
+                "repository": {"full_name": "gsap-broker/governance"},
+                "commits": [{"message": f"{kind}: {json.dumps(payload, default=str)}"}],
+            }, headers={"X-Forgejo-Event": "push"})
+        return cid
+    except Exception as e:
+        logger.warning(f"Chronicle emit failed: {kind}: {e}")
+        return ""

gsap_broker/db.py

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+from sqlmodel import SQLModel
+from sqlalchemy.ext.asyncio import create_async_engine, AsyncEngine
+from sqlmodel.ext.asyncio.session import AsyncSession
+from gsap_broker.settings import settings
+
+engine: AsyncEngine = create_async_engine(settings.database_url, echo=False)
+
+async def init_db():
+    async with engine.begin() as conn:
+        await conn.run_sync(SQLModel.metadata.create_all)
+
+async def get_session():
+    async with AsyncSession(engine) as session:
+        yield session

gsap_broker/db_models.py

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+import uuid
+from datetime import datetime
+from typing import Optional
+from sqlmodel import Field, SQLModel, Column
+from sqlalchemy import JSON
+
+class AuthorizationContextDB(SQLModel, table=True):
+    __tablename__ = "authorization_contexts"
+    context_id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
+    principal_did: str
+    driver_id: str
+    playbook: str
+    corpus_entry_cid: str
+    parameters_cid: str
+    accord_template: str
+    capability_mask: int = 3
+    idp_vendor: str = "keycloak"
+    token_jti: str = ""
+    elevation_active: list = Field(default=[], sa_column=Column(JSON))
+    mfa_satisfied: bool = False
+    status: str = "authorized"
+    issued_at: datetime = Field(default_factory=datetime.utcnow)
+    expires_at: datetime
+    consumed_at: Optional[datetime] = None
+    poll_token: Optional[str] = None
+    chronicle_event_cid: str = ""
+
+class CompletionReceiptDB(SQLModel, table=True):
+    __tablename__ = "completion_receipts"
+    id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
+    context_id: uuid.UUID = Field(foreign_key="authorization_contexts.context_id")
+    outcome: str
+    completed_at: datetime
+    received_at: datetime = Field(default_factory=datetime.utcnow)
+    failure_reason: str = ""
+    chronicle_session_id: str = ""
+    chronicle_events: list = Field(default=[], sa_column=Column(JSON))
+    merkle_root: str = ""
+    behavioral_attestation_status: str = "unavailable"
+    ffc_did: str = ""
+    ffc_signature: str = ""
+    signature_verified: bool = False
+    chronicle_event_cid: str = ""
+
+class ElevationRequestDB(SQLModel, table=True):
+    __tablename__ = "elevation_requests"
+    id: uuid.UUID = Field(default_factory=uuid.uuid4, primary_key=True)
+    principal_id: str = ""
+    role_name: str
+    justification: str = ""
+    duration_minutes: int = 60
+    status: str = "pending"
+    requested_at: datetime = Field(default_factory=datetime.utcnow)
+    expires_at: Optional[datetime] = None

gsap_broker/drivers/__init__.py

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+from .base import IdentityDriver, AuthResult
+from .keycloak import KeycloakDriver
+from .registry import DriverRegistry

gsap_broker/drivers/base.py

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+"""Identity Driver Interface — GSAP §2.2. Zero framework imports."""
+from abc import ABC, abstractmethod
+from dataclasses import dataclass, field
+from typing import Optional
+
+@dataclass
+class ElevationRequired:
+    role: str
+    activation_url: str
+    instructions: str
+    mechanism: str = "custom"
+
+@dataclass
+class AuthResult:
+    STATUS_AUTHORIZED = "authorized"
+    STATUS_PENDING_ELEVATION = "pending_elevation"
+    STATUS_DENIED = "denied"
+
+    status: str
+    principal_did: str = ""
+    display_name: str = ""
+    stable_id: str = ""
+    token_jti: str = ""
+    elevation_active: list = field(default_factory=list)
+    mfa_satisfied: bool = False
+    elevation_required: Optional[ElevationRequired] = None
+    denial_reason: str = ""
+
+    @property
+    def is_authorized(self): return self.status == self.STATUS_AUTHORIZED
+    @property
+    def needs_elevation(self): return self.status == self.STATUS_PENDING_ELEVATION
+
+class IdentityDriver(ABC):
+    def __init__(self, config: dict): self.config = config
+    @abstractmethod
+    async def authenticate(self) -> AuthResult: ...
+    @abstractmethod
+    async def revoke(self, session_id: str) -> None: ...

gsap_broker/drivers/keycloak.py

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+"""Keycloak identity driver — GSAP §2.2."""
+import logging
+from .base import IdentityDriver, AuthResult, ElevationRequired
+
+logger = logging.getLogger(__name__)
+
+class KeycloakDriver(IdentityDriver):
+    async def authenticate(self) -> AuthResult:
+        token_data = self.config.get("_token_data", {})
+        if not token_data:
+            return AuthResult(status=AuthResult.STATUS_DENIED, denial_reason="No token in context.")
+
+        realm_roles = token_data.get("realm_access", {}).get("roles", [])
+        requested_accord = self.config.get("requested_accord", "")
+        required_role = self.config.get("accord_roles", {}).get(requested_accord, "")
+        suffix = self.config.get("elevated_suffix", "-elevated")
+        elevation_active = [r for r in realm_roles if r.endswith(suffix)]
+
+        if required_role and required_role not in realm_roles:
+            return AuthResult(
+                status=AuthResult.STATUS_PENDING_ELEVATION,
+                elevation_required=ElevationRequired(
+                    role=required_role,
+                    activation_url="/governance/elevate/",
+                    instructions=f"Request elevation to '{required_role}' via POST /governance/elevate/",
+                ))
+
+        stable_id = token_data.get("sub", "")
+        template = self.config.get("did_template", "did:web:{domain}/principal/{alias}")
+        domain = self.config.get("domain", "example.com")
+        alias = token_data.get("preferred_username", stable_id)
+
+        return AuthResult(
+            status=AuthResult.STATUS_AUTHORIZED,
+            principal_did=template.format(stable_id=stable_id, domain=domain, alias=alias),
+            display_name=token_data.get("name", alias),
+            stable_id=stable_id, token_jti=token_data.get("jti", ""),
+            elevation_active=elevation_active,
+            mfa_satisfied="otp" in token_data.get("amr", []) or "mfa" in token_data.get("amr", []),
+        )
+
+    async def revoke(self, session_id: str) -> None:
+        logger.info(f"Keycloak revoke: {session_id}")

gsap_broker/drivers/registry.py

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+"""Driver Registry — GSAP §2.5."""
+from .base import IdentityDriver
+from .keycloak import KeycloakDriver
+
+_DRIVERS: dict[str, type[IdentityDriver]] = {"keycloak": KeycloakDriver}
+
+class DriverRegistry:
+    @staticmethod
+    def get(driver_id: str, config: dict) -> IdentityDriver:
+        for vendor, cls in _DRIVERS.items():
+            if driver_id.startswith(vendor) or driver_id == vendor:
+                return cls(config)
+        raise KeyError(f"Driver '{driver_id}' not found. Available: {list(_DRIVERS.keys())}")
+
+    @staticmethod
+    def register(driver_id: str, cls: type[IdentityDriver]) -> None:
+        _DRIVERS[driver_id] = cls
+
+    @staticmethod
+    def list_drivers() -> list[str]:
+        return list(_DRIVERS.keys())

gsap_broker/models/__init__.py

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+from .gsap import *

gsap_broker/models/gsap.py

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+"""GSAP Pydantic models — GCAP-SPEC-SHELLBOUND-BROKER-0001."""
+from datetime import datetime
+from enum import Enum
+from typing import Optional
+from uuid import UUID, uuid4
+from pydantic import BaseModel, Field
+
+class ACStatus(str, Enum):
+    PENDING = "pending"
+    AUTHORIZED = "authorized"
+    CONSUMED = "consumed"
+    EXPIRED = "expired"
+    REVOKED = "revoked"
+
+class Outcome(str, Enum):
+    COMPLETED = "completed"
+    FAILED = "failed"
+    VIOLATED = "violated"
+    TIMED_OUT = "timed_out"
+
+class BehaviorStatus(str, Enum):
+    VERIFIED = "verified"
+    VIOLATED = "violated"
+    UNAVAILABLE = "unavailable"
+
+class Principal(BaseModel):
+    did: str
+    display_name: str = ""
+    broker_session_id: str = ""
+    driver_id: str = ""
+
+class Accord(BaseModel):
+    template: str
+    capability_mask: int = 3
+
+class Operation(BaseModel):
+    playbook: str
+    corpus_entry_cid: str
+    parameters_cid: str
+    apply_authorized_cid: Optional[str] = None
+
+class IdentityProof(BaseModel):
+    idp_vendor: str = "keycloak"
+    token_jti: str = ""
+    elevation_active: list[str] = []
+    mfa_satisfied: bool = False
+
+class AuthorizationContext(BaseModel):
+    gsap_version: str = "0.1.0"
+    context_id: UUID = Field(default_factory=uuid4)
+    issued_at: datetime
+    expires_at: datetime
+    principal: Principal
+    accord: Accord
+    operation: Operation
+    identity_proof: IdentityProof
+    broker: dict = Field(default_factory=dict)
+    signature: Optional[dict] = None
+
+class ChronicleEvidence(BaseModel):
+    session_id: Optional[str] = None
+    events: list[dict] = []
+    merkle_root: Optional[str] = None
+
+class BehavioralAttestation(BaseModel):
+    status: BehaviorStatus = BehaviorStatus.UNAVAILABLE
+    observed_behavior_cid: Optional[str] = None
+    declared_behavior_cid: Optional[str] = None
+
+class AuthorizeRequest(BaseModel):
+    playbook: str
+    corpus_entry_cid: str
+    parameters_cid: str
+    accord_template: str
+    driver_id: str
+
+class AuthorizeResponse(BaseModel):
+    status: str
+    authorization_context: Optional[AuthorizationContext] = None
+    poll_token: Optional[str] = None
+    elevation_instructions: Optional[str] = None
+    activation_url: Optional[str] = None
+
+class CompleteRequest(BaseModel):
+    context_id: UUID
+    outcome: Outcome
+    completed_at: datetime
+    failure_reason: Optional[str] = None
+    chronicle_session_id: Optional[str] = None
+    chronicle_evidence: ChronicleEvidence = Field(default_factory=ChronicleEvidence)
+    behavioral_attestation: BehavioralAttestation = Field(default_factory=BehavioralAttestation)
+    ffc: dict = Field(default_factory=dict)
+    signature: Optional[dict] = None
+
+class CompleteResponse(BaseModel):
+    status: str = "received"
+    receipt_id: UUID
+    signature_verified: bool
+    chronicle_event_cid: Optional[str] = None
+
+class SessionResponse(BaseModel):
+    context_id: UUID
+    principal_did: str
+    accord_template: str
+    playbook: str
+    status: ACStatus
+    issued_at: datetime
+    expires_at: datetime
+    consumed_at: Optional[datetime] = None
+    chronicle_event_cid: Optional[str] = None
+    completion_receipt: Optional[dict] = None
+
+class ElevateRequest(BaseModel):
+    role_name: str
+    justification: str = ""
+    duration_minutes: int = Field(default=60, ge=5, le=480)
+
+class ElevateResponse(BaseModel):
+    status: str
+    elevation_id: Optional[str] = None
+    message: str = ""

gsap_broker/routers/authorize.py

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+"""POST /governance/authorize/ — GSAP §5.2"""
+import secrets, uuid
+from datetime import datetime, timedelta, UTC
+from fastapi import APIRouter, Depends, HTTPException
+from sqlmodel.ext.asyncio.session import AsyncSession
+from gsap_broker.db import get_session
+from gsap_broker.db_models import AuthorizationContextDB
+from gsap_broker.drivers.registry import DriverRegistry
+from gsap_broker.models import (
+    AuthorizeRequest, AuthorizeResponse, AuthorizationContext,
+    Principal, Accord, Operation, IdentityProof)
+from gsap_broker.settings import settings
+from gsap_broker import chronicle
+
+router = APIRouter()
+
+@router.post("/authorize/", response_model=AuthorizeResponse, summary="Issue AC (GSAP §5.2)")
+async def authorize(request: AuthorizeRequest, db: AsyncSession = Depends(get_session)):
+    try:
+        driver = DriverRegistry.get(request.driver_id, config={
+            "requested_accord": request.accord_template,
+            "domain": settings.keycloak_domain,
+            "did_template": settings.keycloak_did_template,
+            "elevated_suffix": settings.keycloak_elevated_role_suffix,
+        })
+    except KeyError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+    auth_result = await driver.authenticate()
+
+    if auth_result.needs_elevation:
+        poll_token = secrets.token_urlsafe(32)
+        ac_db = AuthorizationContextDB(
+            principal_did="", driver_id=request.driver_id, playbook=request.playbook,
+            corpus_entry_cid=request.corpus_entry_cid, parameters_cid=request.parameters_cid,
+            accord_template=request.accord_template, status="pending",
+            expires_at=datetime.now(UTC) + timedelta(minutes=10), poll_token=poll_token)
+        db.add(ac_db); await db.commit()
+        return AuthorizeResponse(
+            status="pending_elevation", poll_token=poll_token,
+            elevation_instructions=auth_result.elevation_required.instructions,
+            activation_url=auth_result.elevation_required.activation_url)
+
+    if not auth_result.is_authorized:
+        raise HTTPException(status_code=403, detail=auth_result.denial_reason)
+
+    now = datetime.now(UTC)
+    expires = now + timedelta(minutes=settings.ac_ttl_minutes)
+    ctx_id = uuid.uuid4()
+
+    ac = AuthorizationContext(
+        context_id=ctx_id, issued_at=now, expires_at=expires,
+        principal=Principal(did=auth_result.principal_did, display_name=auth_result.display_name, driver_id=request.driver_id),
+        accord=Accord(template=request.accord_template),
+        operation=Operation(playbook=request.playbook, corpus_entry_cid=request.corpus_entry_cid, parameters_cid=request.parameters_cid),
+        identity_proof=IdentityProof(token_jti=auth_result.token_jti, elevation_active=auth_result.elevation_active, mfa_satisfied=auth_result.mfa_satisfied),
+        broker={"did": settings.broker_did, "name": settings.broker_name})
+
+    ac_db = AuthorizationContextDB(
+        context_id=ctx_id, principal_did=auth_result.principal_did, driver_id=request.driver_id,
+        playbook=request.playbook, corpus_entry_cid=request.corpus_entry_cid,
+        parameters_cid=request.parameters_cid, accord_template=request.accord_template,
+        token_jti=auth_result.token_jti, elevation_active=auth_result.elevation_active,
+        mfa_satisfied=auth_result.mfa_satisfied, status="authorized", issued_at=now, expires_at=expires)
+    db.add(ac_db)
+    cid = await chronicle.emit("GSAP_AC_ISSUED", {"event_code": "0x2704", "context_id": str(ctx_id), "principal_did": auth_result.principal_did, "playbook": request.playbook})
+    ac_db.chronicle_event_cid = cid
+    await db.commit()
+
+    return AuthorizeResponse(status="authorized", authorization_context=ac)
+
+@router.get("/authorize/{poll_token}/", response_model=AuthorizeResponse, summary="Poll (GSAP §5.3)")
+async def authorize_poll(poll_token: str, db: AsyncSession = Depends(get_session)):
+    from sqlmodel import select
+    result = await db.exec(select(AuthorizationContextDB).where(AuthorizationContextDB.poll_token == poll_token))
+    ac_db = result.first()
+    if not ac_db: raise HTTPException(status_code=404, detail="Not found.")
+    return AuthorizeResponse(status=ac_db.status, poll_token=poll_token)

gsap_broker/routers/complete.py

@@ -0,0 +1,39 @@
+"""POST /governance/complete/ — GSAP §5.4"""
+import uuid
+from datetime import datetime, UTC
+from fastapi import APIRouter, Depends, HTTPException
+from sqlmodel.ext.asyncio.session import AsyncSession
+from sqlmodel import select
+from gsap_broker.db import get_session
+from gsap_broker.db_models import AuthorizationContextDB, CompletionReceiptDB
+from gsap_broker.models import CompleteRequest, CompleteResponse
+from gsap_broker import chronicle
+
+router = APIRouter()
+
+@router.post("/complete/", response_model=CompleteResponse, summary="Receive CR (GSAP §5.4)")
+async def complete(request: CompleteRequest, db: AsyncSession = Depends(get_session)):
+    result = await db.exec(select(AuthorizationContextDB).where(
+        AuthorizationContextDB.context_id == request.context_id,
+        AuthorizationContextDB.status == "authorized"))
+    ac_db = result.first()
+    if not ac_db: raise HTTPException(status_code=404, detail="AC not found or already consumed.")
+
+    sig_verified = bool((request.signature or {}).get("value"))
+    cr_db = CompletionReceiptDB(
+        id=uuid.uuid4(), context_id=request.context_id, outcome=request.outcome.value,
+        completed_at=request.completed_at, failure_reason=request.failure_reason or "",
+        chronicle_session_id=request.chronicle_session_id or "",
+        chronicle_events=request.chronicle_evidence.events,
+        merkle_root=request.chronicle_evidence.merkle_root or "",
+        behavioral_attestation_status=request.behavioral_attestation.status.value,
+        ffc_did=request.ffc.get("did", ""), ffc_signature=(request.signature or {}).get("value", ""),
+        signature_verified=sig_verified)
+    db.add(cr_db)
+    ac_db.status = "consumed"; ac_db.consumed_at = datetime.now(UTC)
+
+    cid = await chronicle.emit("GSAP_CR_RECEIVED", {"event_code": "0x2706", "context_id": str(request.context_id), "outcome": request.outcome.value})
+    cr_db.chronicle_event_cid = cid
+    await db.commit()
+
+    return CompleteResponse(receipt_id=cr_db.id, signature_verified=sig_verified, chronicle_event_cid=cid or None)

gsap_broker/routers/drivers.py

@@ -0,0 +1,8 @@
+from fastapi import APIRouter
+from gsap_broker.drivers.registry import DriverRegistry
+
+router = APIRouter()
+
+@router.get("/drivers/", summary="List drivers (GSAP §2.5)")
+async def list_drivers():
+    return {"drivers": DriverRegistry.list_drivers(), "gsap_version": "0.1.0"}

gsap_broker/routers/elevate.py

@@ -0,0 +1,17 @@
+"""POST /governance/elevate/ — JIT elevation"""
+import uuid
+from fastapi import APIRouter, Depends
+from sqlmodel.ext.asyncio.session import AsyncSession
+from gsap_broker.db import get_session
+from gsap_broker.db_models import ElevationRequestDB
+from gsap_broker.models import ElevateRequest, ElevateResponse
+
+router = APIRouter()
+
+@router.post("/elevate/", response_model=ElevateResponse, summary="Request JIT elevation")
+async def elevate(request: ElevateRequest, db: AsyncSession = Depends(get_session)):
+    er = ElevationRequestDB(id=uuid.uuid4(), role_name=request.role_name,
+                            justification=request.justification, duration_minutes=request.duration_minutes)
+    db.add(er); await db.commit()
+    return ElevateResponse(status="pending", elevation_id=str(er.id),
+                           message=f"Elevation to '{request.role_name}' requested.")

gsap_broker/routers/health.py

@@ -0,0 +1,10 @@
+from fastapi import APIRouter
+from gsap_broker.settings import settings
+
+router = APIRouter()
+
+@router.get("/health/")
+async def health():
+    return {"status": "ok", "broker": settings.broker_name, "did": settings.broker_did,
+            "gsap_version": "0.1.0", "spec": "GCAP-SPEC-SHELLBOUND-BROKER-0001",
+            "chronicle": "enabled" if settings.chronicle_webhook_url else "disabled"}

gsap_broker/routers/session.py

@@ -0,0 +1,31 @@
+"""GET /governance/session/{id}/ — GSAP §5.5"""
+import uuid
+from fastapi import APIRouter, Depends, HTTPException
+from sqlmodel.ext.asyncio.session import AsyncSession
+from sqlmodel import select
+from gsap_broker.db import get_session
+from gsap_broker.db_models import AuthorizationContextDB, CompletionReceiptDB
+from gsap_broker.models import SessionResponse, ACStatus
+
+router = APIRouter()
+
+@router.get("/session/{context_id}/", response_model=SessionResponse, summary="View session (GSAP §5.5)")
+async def session_detail(context_id: uuid.UUID, db: AsyncSession = Depends(get_session)):
+    result = await db.exec(select(AuthorizationContextDB).where(AuthorizationContextDB.context_id == context_id))
+    ac_db = result.first()
+    if not ac_db: raise HTTPException(status_code=404, detail="Not found.")
+
+    cr_result = await db.exec(select(CompletionReceiptDB).where(CompletionReceiptDB.context_id == context_id))
+    cr_db = cr_result.first()
+    cr_data = None
+    if cr_db:
+        cr_data = {"outcome": cr_db.outcome, "behavioral_attestation": cr_db.behavioral_attestation_status,
+                   "chronicle_session_id": cr_db.chronicle_session_id, "received_at": cr_db.received_at.isoformat(),
+                   "signature_verified": cr_db.signature_verified}
+
+    return SessionResponse(
+        context_id=ac_db.context_id, principal_did=ac_db.principal_did,
+        accord_template=ac_db.accord_template, playbook=ac_db.playbook,
+        status=ACStatus(ac_db.status), issued_at=ac_db.issued_at,
+        expires_at=ac_db.expires_at, consumed_at=ac_db.consumed_at,
+        chronicle_event_cid=ac_db.chronicle_event_cid or None, completion_receipt=cr_data)

gsap_broker/settings.py

@@ -0,0 +1,16 @@
+from pydantic_settings import BaseSettings, SettingsConfigDict
+from typing import Optional
+
+class Settings(BaseSettings):
+    model_config = SettingsConfigDict(env_file=".env", case_sensitive=False)
+    broker_did: str = "did:web:gsap-broker.example.com"
+    broker_name: str = "fastapi-gsap"
+    ac_ttl_minutes: int = 30
+    chronicle_webhook_url: Optional[str] = None
+    keycloak_domain: str = "example.com"
+    keycloak_did_template: str = "did:web:{domain}/principal/{alias}"
+    keycloak_elevated_role_suffix: str = "-elevated"
+    database_url: str = "sqlite+aiosqlite:///./gsap_broker.db"
+    cors_origins: list[str] = ["http://localhost:3000", "http://localhost:8000"]
+
+settings = Settings()

pyproject.toml

@@ -0,0 +1,31 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "fastapi-gsap"
+version = "0.1.0"
+description = "Lightweight FastAPI GSAP broker — GCAP-SPEC-SHELLBOUND-BROKER-0001"
+requires-python = ">=3.11"
+dependencies = [
+    "fastapi>=0.111.0",
+    "uvicorn[standard]>=0.29.0",
+    "pydantic>=2.7.0",
+    "pydantic-settings>=2.2.0",
+    "httpx>=0.27.0",
+    "python-jose[cryptography]>=3.3.0",
+    "sqlmodel>=0.0.19",
+    "aiosqlite>=0.20.0",
+    "structlog>=24.1.0",
+]
+
+[project.optional-dependencies]
+dev = ["pytest>=8.0", "pytest-asyncio>=0.23", "httpx>=0.27", "ruff>=0.4", "pytest-mock>=3.14"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py311"
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]

requirements.txt

@@ -0,0 +1,9 @@
+fastapi>=0.111.0
+uvicorn[standard]>=0.29.0
+pydantic>=2.7.0
+pydantic-settings>=2.2.0
+httpx>=0.27.0
+python-jose[cryptography]>=3.3.0
+sqlmodel>=0.0.19
+aiosqlite>=0.20.0
+structlog>=24.1.0

tests/conftest.py

@@ -0,0 +1,21 @@
+import pytest_asyncio
+from httpx import AsyncClient, ASGITransport
+from sqlmodel import SQLModel
+from sqlalchemy.ext.asyncio import create_async_engine
+from gsap_broker.app import app
+from gsap_broker import db as db_module
+
+@pytest_asyncio.fixture(autouse=True)
+async def test_db():
+    engine = create_async_engine("sqlite+aiosqlite:///./test_gsap.db")
+    db_module.engine = engine
+    async with engine.begin() as conn:
+        await conn.run_sync(SQLModel.metadata.create_all)
+    yield
+    async with engine.begin() as conn:
+        await conn.run_sync(SQLModel.metadata.drop_all)
+
+@pytest_asyncio.fixture
+async def client():
+    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as c:
+        yield c

tests/test_broker.py

@@ -0,0 +1,70 @@
+"""Tests for fastapi-gsap broker."""
+import pytest
+from httpx import AsyncClient
+
+@pytest.mark.asyncio
+async def test_health(client: AsyncClient):
+    resp = await client.get("/health/")
+    assert resp.status_code == 200
+    assert resp.json()["gsap_version"] == "0.1.0"
+
+@pytest.mark.asyncio
+async def test_list_drivers(client: AsyncClient):
+    resp = await client.get("/governance/drivers/")
+    assert resp.status_code == 200
+    assert "keycloak" in resp.json()["drivers"]
+
+@pytest.mark.asyncio
+async def test_authorize_bad_driver(client: AsyncClient):
+    resp = await client.post("/governance/authorize/", json={
+        "playbook": "test", "corpus_entry_cid": "sha256:a", "parameters_cid": "sha256:b",
+        "accord_template": "test", "driver_id": "nonexistent"})
+    assert resp.status_code == 400
+
+@pytest.mark.asyncio
+async def test_authorize_no_token(client: AsyncClient):
+    resp = await client.post("/governance/authorize/", json={
+        "playbook": "test", "corpus_entry_cid": "sha256:a", "parameters_cid": "sha256:b",
+        "accord_template": "test", "driver_id": "keycloak"})
+    assert resp.status_code == 403
+
+@pytest.mark.asyncio
+async def test_full_ac_cr_cycle(client: AsyncClient, mocker):
+    from gsap_broker.drivers.base import AuthResult
+    mocker.patch("gsap_broker.drivers.keycloak.KeycloakDriver.authenticate",
+                 return_value=AuthResult(status=AuthResult.STATUS_AUTHORIZED,
+                                         principal_did="did:web:test/p/sam", token_jti="jti-1", mfa_satisfied=True))
+
+    auth_resp = await client.post("/governance/authorize/", json={
+        "playbook": "test-echo", "corpus_entry_cid": "sha256:" + "a"*64,
+        "parameters_cid": "sha256:" + "b"*64, "accord_template": "test-ops", "driver_id": "keycloak"})
+    assert auth_resp.status_code == 200
+    ctx_id = auth_resp.json()["authorization_context"]["context_id"]
+
+    cr_resp = await client.post("/governance/complete/", json={
+        "context_id": ctx_id, "outcome": "completed", "completed_at": "2026-01-01T00:00:00Z"})
+    assert cr_resp.status_code == 200
+
+    session_resp = await client.get(f"/governance/session/{ctx_id}/")
+    assert session_resp.status_code == 200
+    assert session_resp.json()["status"] == "consumed"
+    assert session_resp.json()["completion_receipt"]["outcome"] == "completed"
+
+@pytest.mark.asyncio
+async def test_consumed_ac_rejected(client: AsyncClient, mocker):
+    from gsap_broker.drivers.base import AuthResult
+    mocker.patch("gsap_broker.drivers.keycloak.KeycloakDriver.authenticate",
+                 return_value=AuthResult(status=AuthResult.STATUS_AUTHORIZED,
+                                         principal_did="did:web:test/p/sam", token_jti="jti-2"))
+
+    auth_resp = await client.post("/governance/authorize/", json={
+        "playbook": "test", "corpus_entry_cid": "sha256:x", "parameters_cid": "sha256:y",
+        "accord_template": "test", "driver_id": "keycloak"})
+    ctx_id = auth_resp.json()["authorization_context"]["context_id"]
+
+    await client.post("/governance/complete/", json={
+        "context_id": ctx_id, "outcome": "completed", "completed_at": "2026-01-01T00:00:00Z"})
+
+    second = await client.post("/governance/complete/", json={
+        "context_id": ctx_id, "outcome": "completed", "completed_at": "2026-01-01T00:00:00Z"})
+    assert second.status_code == 404