Public API reference for context_compiler.
This page documents the exported package surface and typical usage patterns. It does not redefine behavioral semantics.
Authoritative behavior documents:
For behavioral semantics, use the authoritative documents above. This page documents the supported public package surface without redefining directive or continuation behavior.
Core boundary:
- core consumes canonical directives
- canonical directive validation remains in core
- semantic validation and authoritative state transitions remain in core
- pending continuation, when supported, is created only by semantic evaluation of canonical directives
- human-facing normalization, malformed-input recovery, and intent drafting are outside the core contract
- core does not convert failed canonical operations into different directives
Create a new engine instance.
Typical use:
from context_compiler import create_engine
engine = create_engine()Parse one user turn and return a deterministic Decision.
Typical use:
decision = engine.step("set premise current project uses uv")Behavior for directive handling and error is defined by the Directive Grammar Specification.
Important grammar contract:
- one input may contain at most one canonical directive
- directive-shaped invalid input is outside the canonical language
erroris reserved for canonical directives that fail semantic evaluation- quote characters do not create protected literal regions inside recognized directive payloads
Canonical grammar helpers are available from the context_compiler.grammar
submodule.
Public grammar surface:
CanonicalDirectiveDirectiveKindValidatedDirectivedecompose_directive(text)validate_directive(text)is_canonical_directive(text)render_directive(kind, /, **operands)
Use this surface for exact canonical validation, canonical directive syntax decomposition, or canonical directive string construction only.
Boundary notes:
- decomposition exposes canonical syntax only
- operands are grammar-level text, not normalized semantic values
- validation returns
Nonefor any non-canonical input - decomposition returns
Nonefor any non-canonical input - rendering is syntax-only and performs no state interpretation
engine.step(...)remains the authority for error, state transitions, and mutation behaviorengine.step(...)is not a general natural-language repair surface; host code should send canonical directives when it wants deterministic mutation- failed replacement requests are not reinterpreted by core into different directives
use <new> instead of <old>with an absent<old>is not a pending or error-only runtime category; it follows the deterministic semantic rules defined in the specification
CanonicalDirective.operands preserves the grammar-recognized operand text.
Core does not lowercase operands, collapse internal operand whitespace, or
convert operand text into engine/domain identifiers at the grammar layer.
Read the current authoritative premise value from a live engine.
Read the current authoritative policy mapping from a live engine.
This property returns a caller-owned copy so callers cannot mutate live engine state through the returned mapping.
Each user message produces a Decision.
class DecisionKind(StrEnum):
NO_DIRECTIVE = "no_directive"
UPDATE = "update"
ERROR = "error"
class Decision(TypedDict):
kind: DecisionKind
message: str | Nonemessage is structurally present on every Decision, but only error
decisions populate it with meaningful content. no_directive and update
return message=None.
Decision kinds:
| kind | Intended host use |
|---|---|
no_directive |
no canonical directive recognized; no authoritative state change; host decides what to do next |
update |
authoritative state changed; host may apply downstream behavior using updated state |
error |
show message; do not continue normal downstream processing yet |
Helper functions:
is_no_directive(decision)is_update(decision)is_error(decision)get_error_message(decision)
get_error_message(decision) encodes the semantic convention above: it returns
the user-facing error text only for error, otherwise None.
Typical use:
from context_compiler import is_error, is_update
decision = engine.step(user_input)
if is_error(decision):
show_to_user(decision["message"])
elif is_update(decision):
apply_runtime_rules()Use engine.premise and engine.policies for live engine-owned reads.
Use engine.export_json() and engine.import_json() for persistence and
restoration.
Typical use:
blocked_tools = sorted(
item for item, value in engine.policies.items() if value == "prohibit"
)See the README’s State Model section for conceptual guidance on premise vs policy usage.
Export authoritative state as canonical JSON text.
Validate and restore authoritative state from exported JSON text.
Use these APIs for authoritative-state transport or persistence only.
Conceptual boundary:
export_json()/import_json()are the current persistence contract- pending continuation, when supported by the engine contract, is runtime state rather than a documented persistence feature
- imported policy keys are normalized during
import_json(...) - if a policy key normalizes to
"", the payload is invalid and is rejected
The public controller and audit surface was retired for the 0.9 line.
Retired APIs include:
- package-root
step(...) context_compiler.auditpreview(...)state_diff(...)- result-envelope and accessor helpers tied to those APIs
Current host integrations should call engine.step(...) directly, read live
state through engine.premise and engine.policies, and persist state
through engine.export_json() / engine.import_json().
Decision-kind constants:
DECISION_NO_DIRECTIVEDECISION_UPDATEDECISION_ERROR
Policy-value constants:
POLICY_USEPOLICY_PROHIBIT
Use these when you want explicit string comparisons without hard-coding literals in host code.
Public result and data object names exported at package root include:
DecisionEngine
These names are part of the public package surface. For the exact portable API export contract used by tests and ports, see tests/fixtures/conformance/api/public-api-v2.json.