Event Structure¶

Module: KERI.Event

Generic KEL events¶

The KELEvent structure is parameterized over a payload type α, making it reusable across different KERI-based protocols:

structure KELEvent (α : Type) where
  sequenceNumber : Nat
  priorDigest : Option Digest
  payload : α
  signer : Key
  signature : Signature

A KEL α is simply List (KELEvent α), stored newest-first.

This structure was originally defined in kelgroups and is extracted here so any KERI-based project can import it.

KERI event payloads¶

graph TD
    EP[EventPayload]
    EP --> ICP["Icp
Inception"]
    EP --> ROT["Rot
Rotation"]
    EP --> IXN["Ixn
Interaction"]
    EP --> RCT["Rct
Receipt"]

    ICP -.- ICP_D["prefix, keys,
next-key commitments,
witnesses"]
    ROT -.- ROT_D["new keys,
new commitments,
witness changes"]
    IXN -.- IXN_D["data anchors
(digests)"]
    RCT -.- RCT_D["receipted
event digest"]

Inception¶

Creates a new KERI identifier. Fields:

• prefix — the SAID (self-addressing identifier), computed as the digest of the inception event itself
• signingThreshold — minimum signatures required (multi-sig)
• keys — current signing key set
• nextThreshold / nextKeys — pre-rotation commitments for the next key set
• witnessThreshold / witnesses — witness configuration

Rotation¶

Replaces the current key set with previously committed next-keys. Supports witness configuration changes.

Interaction¶

Anchors arbitrary data (as digests) to the KEL without changing keys. Used for binding external events to the identifier's timeline.

Receipt¶

A non-transferable witness receipt. Does not modify key state.

Invariants¶

• inception_type / rotation_type — eventType correctly classifies payloads
• prefix_consistent_icp / prefix_consistent_rot — eventPrefix extracts the prefix field from any payload variant