Policy engine overview

The language a policy is written in. delta runs the compiler, so these pages are written for reading and reviewing a policy the policy-generation MCP produced, rather than for building one locally.

All four pages describe policy-engine v0.7.3, the compiler Orchestrator v0.10.0 runs — not the compiler’s newest tag. The version matters more here than the gap between them suggests: v0.7.4 re-encoded every policy and moved every policy id, so a policy written for one patch version is not interchangeable with the next.

Reading a policy The shape of a policy, its types, and how its constraints are evaluated. Start here.

Value encoding The tagged JSON an intent's attrs must carry. Not described by the API schema, which is why this page exists.

Worked policies Ten complete policies, from a single allowlist to carts with object and tree fields.

Policy language reference The full specification: syntax, static and runtime semantics, error model, bytecode and hashing.

Where these pages come from

Worked policies and the language reference are synced verbatim from {UPSTREAM_REPO} — docs/EXAMPLES.md and docs/LANGUAGE.md — by scripts/sync-policy-docs.sh. LANGUAGE.md is the same text the compiler embeds as LANGUAGE_REFERENCE and the MCP serves, so a hand-written copy here would be a third version of one document. Do not edit those two pages; regenerate them.

The sync reads v0.7.3 rather than whatever the upstream checkout has at HEAD, because a page describing a compiler newer than the one delta runs will show a policy that does not compile. src/policy-engine.mjs holds the tag and the commit it resolved to. npm run check:policy-pin asserts both against the Cargo.lock of Orchestrator v0.10.0, and npm run check:policy-docs asserts that these pages are that tag’s text.

Reading a policy and value encoding are written here, because neither has an upstream counterpart: the first is orientation for the managed model, and the second documents a wire format the API schema leaves untyped.

Nothing on these pages is ported from the older delta-mandate-docs. Its policy-engine pages describe a language that no longer exists — intent {} and evidence {} blocks with intent.<field> references, where the current grammar has one parameters block, no evidence block, and parameters.<field>. Those examples would not compile.