Poseidon (LCDSS)

Poseidon is a Windows desktop legal decision support system for private document ingestion, Arabic-aware OCR/embedding workflows, semantic search, evidence-constrained legal querying, local AI model operation, runtime diagnostics, and enterprise deployment.

The production entry point is the WPF desktop application installed through the official WiX/Burn pipeline. The API, Worker Service, Management API, and ProvisioningCheck tools support desktop operation, fleet diagnostics, and release validation.

Architecture

• src/Poseidon.Desktop: WPF desktop shell, first-launch provisioning, diagnostics, model health, ingestion UI, and runtime mode control.
• src/Poseidon.Api: JWT-secured ASP.NET Core API for legal queries, document workflows, and operational endpoints.
• src/Poseidon.WorkerService: Windows worker host for watched-folder ingestion.
• src/Poseidon.Management.Api: management plane for signed heartbeat and command workflows.
• src/Poseidon.ProvisioningCheck: installer/runtime validation executable.
• src/Poseidon.Domain, Application, Ingestion, Retrieval, Infrastructure, Security: shared layered business, model, storage, retrieval, and trust-boundary services.

Runtime Modes

• Full: required LLM and embedding providers are configured, reachable, and integrity-valid.
• Degraded: explicitly declared deployment mode where local LLM is omitted but embeddings and retrieval remain valid.
• Recovery: config, model, provider, secret, or integrity validation failed; diagnostics remain available and normal hosted services are prevented from consuming unsafe state.

Official Installer

The only authoritative production packaging path is WiX/Burn:

.\installer\build-installer.ps1 -Configuration Release -ModelsPath "C:\Poseidon\Models" -BuildProfile Production

Official artifacts:

• installer/output/Poseidon.Installer.msi
• installer/output/Poseidon.Bundle.exe

The installer publishes Desktop and ProvisioningCheck, installs models into [INSTALLDIR]\Models, generates [INSTALLDIR]\appsettings.user.json, writes a deterministic model manifest, validates SHA-256 hashes, and blocks install success when provisioning fails.

Production builds require signed artifacts and secure config. Non-production unsigned/test-model builds are allowed only through explicit flags.

Developer Bootstrap

setup.ps1 is a non-destructive readiness script. It validates the local SDK and repository layout; it does not scaffold, overwrite, or mutate the solution.

.\setup.ps1 -Restore -Build -Test -InstallerReadiness

Pinned SDK: see dotnet_version.txt and global.json.

Validation

Core local gates:

dotnet restore Poseidon.sln
dotnet build Poseidon.sln -c Release --no-restore
dotnet test tests/Poseidon.UnitTests/Poseidon.UnitTests.csproj -c Release --no-build
.\tests\scripts\Test-RepositoryHygiene.ps1
.\installer\build-installer.ps1 -ModelsPath ".artifacts\installer-models" -BuildProfile NonProduction -AllowTestModels -UnsignedDevelopmentBuild
.\installer\Validate-InstallerArtifacts.ps1 -BuildProfile NonProduction -AllowTestModels -AllowUnsigned

Security Model

Production security is fail-closed:

• JWT secrets must be strong, protected, and referenced through secure secret storage.
• Management and agent API keys must be protected and non-placeholder.
• DPAPI secret references are used for production machine/user secrets.
• User config cannot weaken trusted machine model paths, hashes, strict mode, provider security mode, or security policy.
• Local model manifests require exact SHA-256 hashes.
• Installer artifacts and provisioning tools must be signed in production.

See docs/security.md and docs/provisioning.md.

Documentation

• docs/deployment.md: enterprise install and operational deployment.
• docs/installer.md: WiX/Burn packaging contract.
• docs/provisioning.md: first-launch, machine config, model manifest, and recovery behavior.
• docs/security.md: authentication, DPAPI secret storage, signing, and management-plane security.
• deploy/qa/Launch-Issue-Runbook.md: launch diagnostics and support workflow.