ri-agent-graph 0.2.4

Run 9 agents at once — graph-based agent orchestration for Rust with parallel fan-out (up to 16 nodes), fan-in joins, checkpointing, interrupt/resume, and event streaming
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139

use thiserror::Error;

/// The checkpoint-store operation that failed during a configured durable run.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum CheckpointStoreOperation {
    CreateRun,
    RecordAttempt,
    CompleteAttempt,
    FailAttempt,
    SaveStateSnapshot,
    CompleteRun,
    FailRun,
}

impl std::fmt::Display for CheckpointStoreOperation {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        let operation = match self {
            Self::CreateRun => "create run",
            Self::RecordAttempt => "record attempt",
            Self::CompleteAttempt => "complete attempt",
            Self::FailAttempt => "fail attempt",
            Self::SaveStateSnapshot => "save state snapshot",
            Self::CompleteRun => "complete run",
            Self::FailRun => "fail run",
        };
        f.write_str(operation)
    }
}

#[derive(Error, Debug)]
pub enum AgentGraphError {
    #[error("Node not found: {0}")]
    NodeNotFound(String),

    #[error("Routing error: {0}")]
    RoutingError(String),

    #[error("State error: {0}")]
    StateError(String),

    #[error("Max iterations exceeded: {current}/{max}")]
    MaxIterationsExceeded { current: usize, max: usize },

    #[error("Cycle detected: {path:?}")]
    CycleDetected { path: Vec<String> },

    #[error("Checkpoint error: {0}")]
    CheckpointError(String),

    /// A configured granular checkpoint store failed; durable execution cannot continue.
    #[error("Checkpoint store failed to {operation}: {message}")]
    CheckpointStore {
        operation: CheckpointStoreOperation,
        message: String,
    },

    #[error("Checkpoint graph mismatch: expected hash '{expected}', got '{actual}'")]
    CheckpointMismatch { expected: String, actual: String },

    #[error("run not found: {0}")]
    RunNotFound(String),
    #[error("attempt not found: {0}")]
    AttemptNotFound(String),
    #[error("attempt '{attempt_id}' belongs to run '{actual_run}', not '{expected_run}'")]
    AttemptRunMismatch {
        attempt_id: String,
        expected_run: String,
        actual_run: String,
    },
    #[error("invalid checkpoint transition: {0}")]
    InvalidTransition(String),
    #[error("terminal state conflict for run '{0}'")]
    TerminalStateConflict(String),

    #[error("Execution error: {0}")]
    ExecutionError(String),

    #[error("Interrupt at node '{node}'")]
    InterruptError {
        node: String,
        value: Option<serde_json::Value>,
    },

    #[error("Payload error: {0}")]
    PayloadError(String),

    #[error("Cancelled")]
    Cancelled,

    #[error("Serialization error: {0}")]
    SerializationError(#[from] serde_json::Error),

    #[cfg(feature = "checkpointing")]
    #[error("Database error: {0}")]
    DatabaseError(#[from] rusqlite::Error),

    #[error("{0}")]
    Other(String),
}

impl AgentGraphError {
    /// Stable string discriminant for structured logging (PRIMITIVES_CONTRACT §2).
    pub fn kind(&self) -> &'static str {
        match self {
            Self::NodeNotFound(_) => "node_not_found",
            Self::RoutingError(_) => "routing",
            Self::StateError(_) => "state",
            Self::MaxIterationsExceeded { .. } => "max_iterations",
            Self::CycleDetected { .. } => "cycle_detected",
            Self::CheckpointError(_) => "checkpoint",
            Self::CheckpointStore { .. } => "checkpoint_store",
            Self::CheckpointMismatch { .. } => "checkpoint_mismatch",
            Self::RunNotFound(_) => "run_not_found",
            Self::AttemptNotFound(_) => "attempt_not_found",
            Self::AttemptRunMismatch { .. } => "attempt_run_mismatch",
            Self::InvalidTransition(_) => "invalid_transition",
            Self::TerminalStateConflict(_) => "terminal_state_conflict",
            Self::ExecutionError(_) => "execution",
            Self::InterruptError { .. } => "interrupt",
            Self::PayloadError(_) => "payload",
            Self::Cancelled => "cancelled",
            Self::SerializationError(_) => "serialization",
            #[cfg(feature = "checkpointing")]
            Self::DatabaseError(_) => "database",
            Self::Other(_) => "other",
        }
    }
}

pub type Result<T> = std::result::Result<T, AgentGraphError>;

/// Create an interrupt error that can be returned from within a node.
/// This causes the graph executor to pause execution at the current node.
pub fn interrupt(node: impl Into<String>, value: Option<serde_json::Value>) -> AgentGraphError {
    AgentGraphError::InterruptError {
        node: node.into(),
        value,
    }
}