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Chassis documentation

Rendered at https://andreolli-davide.github.io/chassis/.

New here? Start with getting-started.md, then use the guides below for task-oriented detail.

Document Read it for
getting-started.md install, the smallest useful app, where to go next
why-generations.md the problem immutable generations solve, and what it costs
lifecycle.md ownership, scopes, plugin lifecycle, generations, safe unload, shutdown
scopes.md composition scopes: hierarchy, inheritance, narrow views, provenance, explain and diff
agent-composition.md AgentSpec, agent revisions, materialization, pinning, retirement, agent diagnostics
incremental-composition.md semantic identity, impact analysis, structural sharing, reachability, reuse diagnostics
plugin-author-guide.md writing, testing, and shipping a plugin
langgraph.md agent definitions, the run context, graph caching, tools, streaming, interrupts
recipes.md behind a web service, per-tenant composition, hot provider swap, budgets, durability
troubleshooting.md symptom → cause → fix, with the exact diagnostics output
observability.md tracing, snapshots, canonical hashing, redaction, evaluation
security.md trust model, policy, secrets, and what Chassis is not
replay.md record/replay boundaries and their explicit limitations
configuration.md declarative configuration, the catalog, reconciliation, drift
design.md guarantees, decisions, and deliberate absences
migration.md the 0.3 → 0.4, 0.2 → 0.3, and 0.1 → 0.2 changes and how to migrate

Examples

Example Shows
examples/quickstart.py the smallest useful app: a model capability, one LangGraph agent, generation attribution
examples/basic_agent.py a LangGraph agent: model capability, tools, checkpointer, streaming, tracing, interrupt/resume, snapshot
examples/reactive_cascade.py database → memory → agent extension, removed and restored
examples/safe_provider_replacement.py an active run keeping its generation across a provider swap
examples/scoped_composition.py hierarchical scopes: inheritance, sibling isolation, capability narrowing, provenance, diff, pinned runs
examples/agent_composition.py three versioned agents: materialization, narrowing, revision pinning, incremental reuse, retirement

All six execute their own assertions, so running them is the verification:

uv run python examples/quickstart.py
uv run python examples/basic_agent.py
uv run python examples/reactive_cascade.py
uv run python examples/safe_provider_replacement.py
uv run python examples/scoped_composition.py
uv run python examples/agent_composition.py

The core proposition

Chassis allows agent runtime composition to change over time while active runs retain a coherent environment, dependencies react correctly, resources have explicit ownership, and obsolete components are disposed only when they are no longer reachable.