CEL OSS
CEL is the open context and trust data plane for AI agents.
CEL gives agent builders reusable contracts for four things every serious agent runtime needs:
- fuse many sources into one canonical context snapshot
- persist cross-turn memory locally or behind your own backend
- assemble governed model briefs with receipts
- inspect what the agent saw, remembered, sent to the model, and later claimed
The open project is intentionally not the full Cellar runtime. The live cortex engine, policy enforcement, monitoring, compliance workflows, hosted workers, and GUI surfaces are the commercial Cellar/Dilipod operating layer built on these contracts.
OSS Crates
Each crate is published on crates.io and maintained in a standalone repository. This workspace (cellar-oss) mirrors them for integrated examples and shared docs.
| Crate | Repository | Role | Start here | |---|---|---|---| | cel-context | crates.io | ContextElement / ContextSnapshot model and merge mechanics | docs/concepts/context.md | | cel-memory | crates.io | Memory trait, sessions, scopes, write hooks | docs/concepts/memory.md · BACKENDS.md | | cel-memory-sqlite | crates.io | Local SQLite + vector + FTS backend | docs/concepts/memory.md | | cel-brief | crates.io | Brief assembly, budgeting, governance, receipts | docs/concepts/brief.md | | cel-contracts | crates.io | Action, planning, and execution receipt schemas | docs/concepts/receipts.md | | cel-summarizer | crates.io | LLM summarizers for session rollups (Anthropic + Ollama) | docs/migration-0.2.md |
Current release line: 0.2.0 on crates.io. Upgrading from 0.1.x? See docs/migration-0.2.md.
See docs/crates.md for the full crate matrix.
Architecture
+------------------------------------------------------------+
| Agents LangGraph | Mastra | Claude Code | Cursor |
| Codex | GPT | Gemini | n8n | MCP clients |
+------------------------------------------------------------+
| Cellar live cortex runtime, policy, monitoring, |
| runtime compliance, hosted execution, GUI workflows |
+------------------------------------------------------------+
| CEL OSS context snapshots, memory, brief assembly, |
| contracts transport schemas, receipts |
+------------------------------------------------------------+
| Sources browser | desktop apps | logs | traces | APIs |
+------------------------------------------------------------+Quickstart
Use the OSS contracts without the full runtime. Clone a standalone crate repo, or run from this workspace:
# standalone repo (from repo root)
cargo run --example context_snapshot -- --json
cargo run --example basic
cargo run --example standalone
cargo run --features memory --example with_memory
# this workspace
cargo run -p cel-context --example context_snapshot -- --json
cargo run -p cel-memory --example basic
cargo run -p cel-memory-sqlite --example basic
cargo run -p cel-brief --example standalone
cargo run -p cel-brief --features memory --example with_memoryFor a guided path, read docs/quickstart.md.
Examples
The top-level examples are organized by job-to-be-done:
- examples/merge-context — emit or capture multiple sources into one
ContextSnapshot. - examples/memory-provider — store and retrieve memory through the
MemoryProvidertrait. - examples/build-brief — build a governed prompt bundle and inspect its receipt.
- examples/receipt-inspection — understand action and brief receipts.
- examples/context-to-brief — connect context, memory, and brief assembly end-to-end.
Commercial Boundary
Open CEL provides the contracts. Cellar/Dilipod operates those contracts in a live environment:
| Open CEL | Commercial Cellar/Dilipod | |---|---| | Context schema and merge contracts | Live cortex runtime | | Memory and SQLite backend | Policy enforcement and approvals | | Brief assembly and brief receipts | Monitoring, alerting, audit timeline | | Receipt and transport schemas | Compliance exports and hosted workers |
See docs/oss-boundary.md and docs/commercial-model.md.
License
Open CEL crates and docs are Apache-2.0 unless a subdirectory states otherwise.
