Module headers 

Constants

AGENT_ID

Header key: the producing agent’s id.

AGENT_VERSION

Header key: the agent envelope’s wire version (u32 typed value). Rides outside the CBOR body so projections, a viewer, and rolling-upgrade consumers pick the decoder (and filter per version) without decoding the body.

CAUSAL_PARENT

Header key: the message this one is a reply to.

CONTENT_TYPE

Header key: the wire codec tag (u8 code, see ContentType::code).

CONVERSATION_FIELD

The projected-column name a deployment materializes the CONVERSATION_ID header under, so every projection row is filterable by the conversation that produced it without a producer stamping an index header. The stable short field name the query surface’s conversation lens and the graph/KV conversation columns all agree on.

CONVERSATION_ID

Header key: conversation id (OTel gen_ai.conversation.id).

CORRELATION_ID

Header key for the generic request/reply correlation id. Short on purpose (it rides every request/reply pair) and independent of any agentic header so the generic substrate works without provenance.

COST_USD

Header key: LLM call cost in USD.

DEADLINE

Header key: drop-dead time (epoch micros).

DELEGATED_BY

Header key: reserved alias for an on-behalf-of subject. Signed delegation uses the envelope metadata key on_behalf_of.

FENCE

Header key: the strictly-monotonic per-task fence the producer held (u64). A consumer rejects a log-resident effect whose fence is below the highest it has accepted for the task, so a stale-holder replay cannot re-fire.

FIELD_MESSAGE_TYPE

Reserved indexed-field name for the event type.

FIELD_TS

Reserved indexed-field name for the timestamp (epoch micros).

HEADER_FRAMING_BYTES

Per-header wire overhead counted toward the soft cap (key length, value kind, value length), so the cap reflects on-wire size.

HEADER_SOFT_CAP

Soft cap on total header bytes per record.

HEADER_VALUE_MAX

Maximum bytes in a single header value (Iggy serializes the length as u8).

IDEMPOTENCY_KEY

Header key: dedup / reply-correlation key.

IDX_PREFIX

Prefix marking an indexed-field header (agdx.idx.<name>).

INLINE_PAYLOAD

Header key: per-record inline-payload override (bool typed value). Stamped so the projector keeps a copy of the opaque payload bytes inline with the materialized row. Absent means the index row carries only indexed scalars and metadata while Iggy keeps the original body in the log.

MEMORY_APP

Header key: the app scope layer. Unscoped recall widens across it.

MEMORY_NAMESPACE

Header key: the logical memory namespace the read view materializes under.

MEMORY_USER

Header key: the user scope layer. Unscoped recall widens across it.

PARENT_CONVERSATION_ID

Header key: the conversation this was spawned from.

PROJECTION_REF

Header key: which projection a record routes to. Opaque string by design (a name + version like "order.v1"), deliberately distinct from agdx.sid, which selects a codec’s writer schema rather than a materialization rule.

ROOT_CONVERSATION_ID

Header key: the root of the conversation tree.

SCHEMA_ID

Header key carrying the u32 writer-schema id (typed header value) for a schema-first codec (Avro, Protobuf). The LaserData Cloud resolves it against its schema registry to decode the body. A bridge that lives in LaserData Cloud until Iggy gains native schema dispatch.

TARGET_AGENT_ID

Header key: the agent this message is addressed to.

USAGE_INPUT_TOKENS

Header key: LLM input/prompt tokens.

USAGE_OUTPUT_TOKENS

Header key: LLM output/completion tokens.

VECTOR_FIELD

Default field/pointer for the embedding vector.

WINDOW_START

Result-row header key carrying a tumbling window’s lower edge (epoch micros) when an aggregate query sets a window. Byte-identical to the LaserData Cloud’s window_start column.