Event schema

type Event struct {
    RunID     string             `cbor:"run_id"`     // ULID, per-run identifier
    Seq       uint64             `cbor:"seq"`        // monotonic per run, starts at 1
    PrevHash  []byte             `cbor:"prev_hash"`  // BLAKE3 of canonical CBOR of prev event
    Timestamp int64              `cbor:"ts"`         // unix nanoseconds (from step.Now)
    Kind      Kind               `cbor:"kind"`       // discriminator
    Payload   cborenc.RawMessage `cbor:"payload"`    // kind-specific struct, CBOR-encoded
}

type RunStarted struct {
    SchemaVersion    uint32
    Goal             string
    ProviderID       string
    ModelID          string
    APIVersion       string
    ParamsHash       []byte
    Params           cborenc.RawMessage
    SystemPromptHash []byte
    SystemPrompt     string
    ToolRegistryHash []byte
    ToolSchemas      []ToolSchemaRef
    Budget           *BudgetLimits
    StarlingVersion  string  // linked module version
    AppVersion       string  // caller-supplied
}

type TurnStarted struct {
    TurnID      string
    PromptHash  []byte
    InputTokens int64
}

type AssistantMessageCompleted struct {
    TurnID            string
    Text              string
    ToolUses          []PlannedToolUse
    StopReason        string
    InputTokens       int64
    OutputTokens      int64
    CacheReadTokens   int64
    CacheCreateTokens int64
    CostUSD           float64
    RawResponseHash   []byte  // BLAKE3 of canonicalized provider response
    ProviderRequestID string
}

type ReasoningEmitted struct {
    TurnID    string
    Content   string
    Sensitive bool
    Signature []byte  // Anthropic per-block integrity signature
    Redacted  bool    // true when Content is the opaque redacted_thinking payload
}

type ToolCallScheduled struct {
    CallID   string
    TurnID   string
    ToolName string
    Args     cborenc.RawMessage
    Attempt  uint32
    IdempKey string
}

type ToolCallCompleted struct {
    CallID     string
    Result     cborenc.RawMessage
    DurationMs int64
    Attempt    uint32
}

type ToolCallFailed struct {
    CallID     string
    Error      string
    ErrorType  string  // "timeout" | "panic" | "tool" | "cancelled"
    DurationMs int64
    Attempt    uint32
}

type SideEffectRecorded struct {
    Name  string
    Value cborenc.RawMessage
}

type BudgetExceeded struct {
    Limit         string  // "input_tokens" | "output_tokens" | "usd" | "wall_clock"
    Cap           float64
    Actual        float64
    Where         string  // "pre_call" | "mid_stream" | "post_call"
    TurnID        string
    CallID        string
    PartialText   string
    PartialTokens int64
}

type RunResumed struct {
    AtSeq        uint64  // last seq from the prior process
    ExtraMessage string
    ReissueTools bool
    PendingCalls int
}

seq=1  RunStarted                  prev=nil
seq=2  TurnStarted                 prev=H(seq1)  turn=T1
seq=3  AssistantMessageCompleted   prev=H(seq2)  turn=T1, tool_uses=[C1, C2]
seq=4  ToolCallScheduled           prev=H(seq3)  call=C1, attempt=1
seq=5  ToolCallScheduled           prev=H(seq4)  call=C2, attempt=1
seq=6  ToolCallCompleted           prev=H(seq5)  call=C2, attempt=1
seq=7  ToolCallCompleted           prev=H(seq6)  call=C1, attempt=1
seq=8  TurnStarted                 prev=H(seq7)  turn=T2
seq=9  AssistantMessageCompleted   prev=H(seq8)  turn=T2, no tool_uses
seq=10 RunCompleted                prev=H(seq9)  merkle_root=M(seq1..seq9)