treeship_core/statements/
mod.rs

1/// Returns the canonical MIME payloadType for a statement type suffix.
2///
3/// ```
4/// use treeship_core::statements::payload_type;
5/// assert_eq!(
6///     payload_type("action"),
7///     "application/vnd.treeship.action.v1+json"
8/// );
9/// ```
10pub fn payload_type(suffix: &str) -> String {
11    format!("application/vnd.treeship.{}.v1+json", suffix)
12}
13
14pub const TYPE_ACTION:      &str = "treeship/action/v1";
15pub const TYPE_APPROVAL:    &str = "treeship/approval/v1";
16pub const TYPE_HANDOFF:     &str = "treeship/handoff/v1";
17pub const TYPE_ENDORSEMENT: &str = "treeship/endorsement/v1";
18pub const TYPE_RECEIPT:     &str = "treeship/receipt/v1";
19pub const TYPE_BUNDLE:      &str = "treeship/bundle/v1";
20pub const TYPE_DECISION:    &str = "treeship/decision/v1";
21
22use serde::{Deserialize, Serialize};
23
24/// A reference to content being attested, approved, or receipted.
25/// At least one field should be set.
26#[derive(Debug, Clone, Default, Serialize, Deserialize)]
27pub struct SubjectRef {
28    /// Content hash: "sha256:<hex>" or "sha3:<hex>"
29    #[serde(skip_serializing_if = "Option::is_none")]
30    pub digest: Option<String>,
31
32    /// External URI to the content
33    #[serde(skip_serializing_if = "Option::is_none")]
34    pub uri: Option<String>,
35
36    /// ID of another Treeship artifact
37    #[serde(rename = "artifactId", skip_serializing_if = "Option::is_none")]
38    pub artifact_id: Option<String>,
39}
40
41/// Scope constraints on an approval — what it permits and for how long.
42#[derive(Debug, Clone, Default, Serialize, Deserialize)]
43pub struct ApprovalScope {
44    /// Maximum number of actions this approval authorises.
45    #[serde(rename = "maxActions", skip_serializing_if = "Option::is_none")]
46    pub max_actions: Option<u32>,
47
48    /// ISO 8601 timestamp after which the approval is no longer valid.
49    #[serde(rename = "validUntil", skip_serializing_if = "Option::is_none")]
50    pub valid_until: Option<String>,
51
52    /// If set, only these action labels are permitted.
53    #[serde(rename = "allowedActions", skip_serializing_if = "Vec::is_empty", default)]
54    pub allowed_actions: Vec<String>,
55
56    /// Arbitrary additional constraints (e.g. max payment amount).
57    #[serde(skip_serializing_if = "Option::is_none")]
58    pub extra: Option<serde_json::Value>,
59}
60
61/// Records that an actor performed an action.
62///
63/// This is the most common statement type — every tool call, API request,
64/// file write, or agent operation produces one.
65#[derive(Debug, Clone, Serialize, Deserialize)]
66pub struct ActionStatement {
67    /// Always `TYPE_ACTION`
68    #[serde(rename = "type")]
69    pub type_: String,
70
71    /// RFC 3339 timestamp, set at sign time.
72    pub timestamp: String,
73
74    /// DID-style actor URI. e.g. "agent://researcher", "human://alice"
75    pub actor: String,
76
77    /// Dot-namespaced action label. e.g. "tool.call", "stripe.charge.create"
78    pub action: String,
79
80    #[serde(default, skip_serializing_if = "is_empty_subject")]
81    pub subject: SubjectRef,
82
83    /// Links this artifact to its parent in the chain.
84    #[serde(rename = "parentId", skip_serializing_if = "Option::is_none")]
85    pub parent_id: Option<String>,
86
87    /// Must match the `nonce` field of the approval authorising this action.
88    /// Provides cryptographic one-to-one binding between approval and action,
89    /// preventing approval reuse across multiple actions.
90    #[serde(rename = "approvalNonce", skip_serializing_if = "Option::is_none")]
91    pub approval_nonce: Option<String>,
92
93    #[serde(rename = "policyRef", skip_serializing_if = "Option::is_none")]
94    pub policy_ref: Option<String>,
95
96    #[serde(skip_serializing_if = "Option::is_none")]
97    pub meta: Option<serde_json::Value>,
98}
99
100/// Records that an approver authorised an intent or action.
101///
102/// The `nonce` field is the cornerstone of approval security: the consuming
103/// `ActionStatement` must echo the same nonce in its `approval_nonce` field.
104/// This cryptographically binds each approval to exactly one action (or
105/// `max_actions` actions when set), preventing approval reuse.
106#[derive(Debug, Clone, Serialize, Deserialize)]
107pub struct ApprovalStatement {
108    #[serde(rename = "type")]
109    pub type_: String,
110    pub timestamp: String,
111
112    /// DID-style approver URI. e.g. "human://alice"
113    pub approver: String,
114
115    #[serde(default, skip_serializing_if = "is_empty_subject")]
116    pub subject: SubjectRef,
117
118    #[serde(skip_serializing_if = "Option::is_none")]
119    pub description: Option<String>,
120
121    /// ISO 8601 expiry timestamp. None means no expiry.
122    #[serde(rename = "expiresAt", skip_serializing_if = "Option::is_none")]
123    pub expires_at: Option<String>,
124
125    /// Whether the receiving actor may re-delegate this approval.
126    pub delegatable: bool,
127
128    /// Random token. The consuming ActionStatement must set its
129    /// `approval_nonce` field to this value. Generated by the SDK if
130    /// not provided by the caller.
131    pub nonce: String,
132
133    #[serde(skip_serializing_if = "Option::is_none")]
134    pub scope: Option<ApprovalScope>,
135
136    #[serde(rename = "policyRef", skip_serializing_if = "Option::is_none")]
137    pub policy_ref: Option<String>,
138
139    #[serde(skip_serializing_if = "Option::is_none")]
140    pub meta: Option<serde_json::Value>,
141}
142
143/// Records that work moved from one actor/domain to another.
144///
145/// This is the core of Treeship's multi-agent trust story. A handoff
146/// artifact proves custody transfer and carries inherited approvals.
147#[derive(Debug, Clone, Serialize, Deserialize)]
148pub struct HandoffStatement {
149    #[serde(rename = "type")]
150    pub type_: String,
151    pub timestamp: String,
152
153    /// Source actor URI
154    pub from: String,
155    /// Destination actor URI
156    pub to: String,
157
158    /// IDs of artifacts being transferred
159    pub artifacts: Vec<String>,
160
161    /// Approval artifact IDs the receiving actor inherits
162    #[serde(rename = "approvalIds", default, skip_serializing_if = "Vec::is_empty")]
163    pub approval_ids: Vec<String>,
164
165    /// Constraints the receiving actor must satisfy
166    #[serde(default, skip_serializing_if = "Vec::is_empty")]
167    pub obligations: Vec<String>,
168
169    pub delegatable: bool,
170
171    #[serde(rename = "taskRef", skip_serializing_if = "Option::is_none")]
172    pub task_ref: Option<String>,
173
174    #[serde(rename = "policyRef", skip_serializing_if = "Option::is_none")]
175    pub policy_ref: Option<String>,
176
177    #[serde(skip_serializing_if = "Option::is_none")]
178    pub meta: Option<serde_json::Value>,
179}
180
181/// Records that a signer asserts confidence about an existing artifact.
182///
183/// Used for post-hoc validation, compliance sign-off, countersignatures.
184#[derive(Debug, Clone, Serialize, Deserialize)]
185pub struct EndorsementStatement {
186    #[serde(rename = "type")]
187    pub type_: String,
188    pub timestamp: String,
189
190    /// DID-style endorser URI
191    pub endorser: String,
192    pub subject: SubjectRef,
193
194    /// Endorsement category: "validation", "compliance", "countersignature",
195    /// "review", or any custom string.
196    pub kind: String,
197
198    #[serde(skip_serializing_if = "Option::is_none")]
199    pub rationale: Option<String>,
200
201    #[serde(rename = "expiresAt", skip_serializing_if = "Option::is_none")]
202    pub expires_at: Option<String>,
203
204    #[serde(rename = "policyRef", skip_serializing_if = "Option::is_none")]
205    pub policy_ref: Option<String>,
206
207    #[serde(skip_serializing_if = "Option::is_none")]
208    pub meta: Option<serde_json::Value>,
209}
210
211/// Records that an external system observed or confirmed an event.
212///
213/// Used for Stripe webhooks, RFC 3161 timestamps, inclusion proofs.
214#[derive(Debug, Clone, Serialize, Deserialize)]
215pub struct ReceiptStatement {
216    #[serde(rename = "type")]
217    pub type_: String,
218    pub timestamp: String,
219
220    /// URI of the system producing this receipt.
221    /// e.g. "system://stripe-webhook", "system://tsauthority"
222    pub system: String,
223
224    #[serde(skip_serializing_if = "Option::is_none")]
225    pub subject: Option<SubjectRef>,
226
227    /// Receipt category: "confirmation", "timestamp", "inclusion", "webhook"
228    pub kind: String,
229
230    #[serde(skip_serializing_if = "Option::is_none")]
231    pub payload: Option<serde_json::Value>,
232
233    #[serde(rename = "payloadDigest", skip_serializing_if = "Option::is_none")]
234    pub payload_digest: Option<String>,
235
236    #[serde(rename = "policyRef", skip_serializing_if = "Option::is_none")]
237    pub policy_ref: Option<String>,
238
239    #[serde(skip_serializing_if = "Option::is_none")]
240    pub meta: Option<serde_json::Value>,
241}
242
243/// A reference to one artifact within a bundle.
244#[derive(Debug, Clone, Serialize, Deserialize)]
245pub struct ArtifactRef {
246    pub id:     String,
247    pub digest: String,
248    #[serde(rename = "type")]
249    pub type_:  String,
250}
251
252/// Groups a set of artifacts into a named, signed bundle.
253#[derive(Debug, Clone, Serialize, Deserialize)]
254pub struct BundleStatement {
255    #[serde(rename = "type")]
256    pub type_: String,
257    pub timestamp: String,
258
259    #[serde(skip_serializing_if = "Option::is_none")]
260    pub tag: Option<String>,
261
262    #[serde(skip_serializing_if = "Option::is_none")]
263    pub description: Option<String>,
264
265    pub artifacts: Vec<ArtifactRef>,
266
267    #[serde(rename = "policyRef", skip_serializing_if = "Option::is_none")]
268    pub policy_ref: Option<String>,
269
270    #[serde(skip_serializing_if = "Option::is_none")]
271    pub meta: Option<serde_json::Value>,
272}
273
274/// Records an agent's reasoning and decision context.
275///
276/// This is the "why" layer -- agents provide this explicitly to explain
277/// inference decisions, model usage, and confidence levels.
278#[derive(Debug, Clone, Serialize, Deserialize)]
279pub struct DecisionStatement {
280    /// Always `TYPE_DECISION`
281    #[serde(rename = "type")]
282    pub type_: String,
283
284    /// RFC 3339 timestamp, set at sign time.
285    pub timestamp: String,
286
287    /// DID-style actor URI. e.g. "agent://analyst"
288    pub actor: String,
289
290    /// Links this artifact to its parent in the chain.
291    #[serde(rename = "parentId", skip_serializing_if = "Option::is_none")]
292    pub parent_id: Option<String>,
293
294    /// Model used for inference. e.g. "claude-opus-4"
295    #[serde(skip_serializing_if = "Option::is_none")]
296    pub model: Option<String>,
297
298    /// Model version if known.
299    #[serde(rename = "modelVersion", skip_serializing_if = "Option::is_none")]
300    pub model_version: Option<String>,
301
302    /// Number of input tokens consumed.
303    #[serde(rename = "tokensIn", skip_serializing_if = "Option::is_none")]
304    pub tokens_in: Option<u64>,
305
306    /// Number of output tokens produced.
307    #[serde(rename = "tokensOut", skip_serializing_if = "Option::is_none")]
308    pub tokens_out: Option<u64>,
309
310    /// SHA-256 digest of the full prompt (not the prompt itself).
311    #[serde(rename = "promptDigest", skip_serializing_if = "Option::is_none")]
312    pub prompt_digest: Option<String>,
313
314    /// Human-readable summary of the decision.
315    #[serde(skip_serializing_if = "Option::is_none")]
316    pub summary: Option<String>,
317
318    /// Confidence level 0.0-1.0 if the agent provides it.
319    #[serde(skip_serializing_if = "Option::is_none")]
320    pub confidence: Option<f64>,
321
322    /// Other options the agent considered.
323    #[serde(skip_serializing_if = "Option::is_none")]
324    pub alternatives: Option<Vec<String>>,
325
326    /// Arbitrary additional metadata.
327    #[serde(skip_serializing_if = "Option::is_none")]
328    pub meta: Option<serde_json::Value>,
329}
330
331// Helpers for skip_serializing_if
332fn is_empty_subject(s: &SubjectRef) -> bool {
333    s.digest.is_none() && s.uri.is_none() && s.artifact_id.is_none()
334}
335
336// --- Constructors ---
337
338impl ActionStatement {
339    pub fn new(actor: impl Into<String>, action: impl Into<String>) -> Self {
340        Self {
341            type_: TYPE_ACTION.into(),
342            timestamp: now_rfc3339(),
343            actor: actor.into(),
344            action: action.into(),
345            subject: SubjectRef::default(),
346            parent_id: None,
347            approval_nonce: None,
348            policy_ref: None,
349            meta: None,
350        }
351    }
352}
353
354impl ApprovalStatement {
355    pub fn new(approver: impl Into<String>, nonce: impl Into<String>) -> Self {
356        Self {
357            type_: TYPE_APPROVAL.into(),
358            timestamp: now_rfc3339(),
359            approver: approver.into(),
360            subject: SubjectRef::default(),
361            description: None,
362            expires_at: None,
363            delegatable: false,
364            nonce: nonce.into(),
365            scope: None,
366            policy_ref: None,
367            meta: None,
368        }
369    }
370}
371
372impl HandoffStatement {
373    pub fn new(
374        from:      impl Into<String>,
375        to:        impl Into<String>,
376        artifacts: Vec<String>,
377    ) -> Self {
378        Self {
379            type_: TYPE_HANDOFF.into(),
380            timestamp: now_rfc3339(),
381            from: from.into(),
382            to: to.into(),
383            artifacts,
384            approval_ids: vec![],
385            obligations: vec![],
386            delegatable: false,
387            task_ref: None,
388            policy_ref: None,
389            meta: None,
390        }
391    }
392}
393
394impl ReceiptStatement {
395    pub fn new(system: impl Into<String>, kind: impl Into<String>) -> Self {
396        Self {
397            type_: TYPE_RECEIPT.into(),
398            timestamp: now_rfc3339(),
399            system: system.into(),
400            subject: None,
401            kind: kind.into(),
402            payload: None,
403            payload_digest: None,
404            policy_ref: None,
405            meta: None,
406        }
407    }
408}
409
410impl DecisionStatement {
411    pub fn new(actor: impl Into<String>) -> Self {
412        Self {
413            type_: TYPE_DECISION.into(),
414            timestamp: now_rfc3339(),
415            actor: actor.into(),
416            parent_id: None,
417            model: None,
418            model_version: None,
419            tokens_in: None,
420            tokens_out: None,
421            prompt_digest: None,
422            summary: None,
423            confidence: None,
424            alternatives: None,
425            meta: None,
426        }
427    }
428}
429
430fn now_rfc3339() -> String {
431    // std::time gives us duration since UNIX_EPOCH.
432    // Format as ISO 8601 / RFC 3339 without pulling in chrono.
433    use std::time::{SystemTime, UNIX_EPOCH};
434    let secs = SystemTime::now()
435        .duration_since(UNIX_EPOCH)
436        .unwrap_or_default()
437        .as_secs();
438    unix_to_rfc3339(secs)
439}
440
441pub fn unix_to_rfc3339(secs: u64) -> String {
442    // Minimal RFC 3339 formatter — no external deps.
443    // Accurate for dates 1970–2099.
444    let s = secs;
445    let (y, mo, d, h, mi, sec) = seconds_to_ymd_hms(s);
446    format!("{:04}-{:02}-{:02}T{:02}:{:02}:{:02}Z", y, mo, d, h, mi, sec)
447}
448
449fn seconds_to_ymd_hms(s: u64) -> (u64, u64, u64, u64, u64, u64) {
450    let sec  = s % 60;
451    let mins = s / 60;
452    let min  = mins % 60;
453    let hrs  = mins / 60;
454    let hour = hrs % 24;
455    let days = hrs / 24;
456
457    // Gregorian calendar calculation from day count
458    let (y, m, d) = days_to_ymd(days);
459    (y, m, d, hour, min, sec)
460}
461
462fn days_to_ymd(days: u64) -> (u64, u64, u64) {
463    // Days since 1970-01-01
464    let mut d = days;
465    let mut year = 1970u64;
466    loop {
467        let dy = if is_leap(year) { 366 } else { 365 };
468        if d < dy { break; }
469        d -= dy;
470        year += 1;
471    }
472    let months = if is_leap(year) {
473        [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
474    } else {
475        [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
476    };
477    let mut month = 1u64;
478    for dm in months {
479        if d < dm { break; }
480        d -= dm;
481        month += 1;
482    }
483    (year, month, d + 1)
484}
485
486fn is_leap(y: u64) -> bool {
487    (y % 4 == 0 && y % 100 != 0) || (y % 400 == 0)
488}
489
490#[cfg(test)]
491mod tests {
492    use super::*;
493    use crate::attestation::{sign, Ed25519Signer, Verifier};
494
495    #[test]
496    fn payload_type_format() {
497        assert_eq!(
498            payload_type("action"),
499            "application/vnd.treeship.action.v1+json"
500        );
501        assert_eq!(
502            payload_type("approval"),
503            "application/vnd.treeship.approval.v1+json"
504        );
505    }
506
507    #[test]
508    fn action_statement_sign_verify() {
509        let signer   = Ed25519Signer::generate("key_test").unwrap();
510        let verifier = Verifier::from_signer(&signer);
511
512        let mut stmt = ActionStatement::new("agent://researcher", "tool.call");
513        stmt.parent_id = Some("art_aabbccdd11223344aabbccdd11223344".into());
514
515        let pt     = payload_type("action");
516        let result = sign(&pt, &stmt, &signer).unwrap();
517
518        assert!(result.artifact_id.starts_with("art_"));
519
520        let vr = verifier.verify(&result.envelope).unwrap();
521        assert_eq!(vr.artifact_id, result.artifact_id);
522
523        // Decode and check the payload survived serialization
524        let decoded: ActionStatement = result.envelope.unmarshal_statement().unwrap();
525        assert_eq!(decoded.actor, "agent://researcher");
526        assert_eq!(decoded.action, "tool.call");
527        assert_eq!(decoded.type_, TYPE_ACTION);
528    }
529
530    #[test]
531    fn approval_statement_with_nonce() {
532        let signer = Ed25519Signer::generate("key_human").unwrap();
533
534        let mut approval = ApprovalStatement::new("human://alice", "nonce_abc123");
535        approval.description = Some("approve laptop purchase < $1500".into());
536        approval.scope = Some(ApprovalScope {
537            max_actions: Some(1),
538            allowed_actions: vec!["stripe.payment_intent.create".into()],
539            ..Default::default()
540        });
541
542        let pt     = payload_type("approval");
543        let result = sign(&pt, &approval, &signer).unwrap();
544        assert!(result.artifact_id.starts_with("art_"));
545
546        let decoded: ApprovalStatement = result.envelope.unmarshal_statement().unwrap();
547        assert_eq!(decoded.nonce, "nonce_abc123");
548        assert_eq!(decoded.scope.unwrap().max_actions, Some(1));
549    }
550
551    #[test]
552    fn handoff_statement() {
553        let signer = Ed25519Signer::generate("key_agent").unwrap();
554
555        let handoff = HandoffStatement::new(
556            "agent://researcher",
557            "agent://checkout",
558            vec!["art_aabbccdd11223344aabbccdd11223344".into()],
559        );
560
561        let pt     = payload_type("handoff");
562        let result = sign(&pt, &handoff, &signer).unwrap();
563        let decoded: HandoffStatement = result.envelope.unmarshal_statement().unwrap();
564
565        assert_eq!(decoded.from, "agent://researcher");
566        assert_eq!(decoded.to,   "agent://checkout");
567        assert_eq!(decoded.artifacts.len(), 1);
568    }
569
570    #[test]
571    fn receipt_statement() {
572        let signer = Ed25519Signer::generate("key_system").unwrap();
573
574        let mut receipt = ReceiptStatement::new("system://stripe-webhook", "confirmation");
575        receipt.payload = Some(serde_json::json!({
576            "eventId": "evt_abc123",
577            "status": "succeeded"
578        }));
579
580        let pt     = payload_type("receipt");
581        let result = sign(&pt, &receipt, &signer).unwrap();
582        let decoded: ReceiptStatement = result.envelope.unmarshal_statement().unwrap();
583
584        assert_eq!(decoded.system, "system://stripe-webhook");
585        assert_eq!(decoded.kind,   "confirmation");
586    }
587
588    #[test]
589    fn nonce_binding_survives_serialization() {
590        let signer   = Ed25519Signer::generate("key_test").unwrap();
591
592        // The nonce in the approval must survive a sign→verify→decode round-trip.
593        // The verifier checks that action.approval_nonce == approval.nonce.
594        let approval = ApprovalStatement::new("human://alice", "secure_nonce_xyz");
595        let pt       = payload_type("approval");
596        let signed   = sign(&pt, &approval, &signer).unwrap();
597
598        let decoded: ApprovalStatement = signed.envelope.unmarshal_statement().unwrap();
599        assert_eq!(decoded.nonce, "secure_nonce_xyz", "nonce must survive serialization");
600    }
601
602    #[test]
603    fn decision_statement_sign_verify() {
604        let signer = Ed25519Signer::generate("key_test").unwrap();
605        let verifier = Verifier::from_signer(&signer);
606
607        let mut stmt = DecisionStatement::new("agent://analyst");
608        stmt.model = Some("claude-opus-4".into());
609        stmt.tokens_in = Some(8432);
610        stmt.tokens_out = Some(1247);
611        stmt.summary = Some("Contract looks standard.".into());
612        stmt.confidence = Some(0.91);
613
614        let pt = payload_type("decision");
615        let result = sign(&pt, &stmt, &signer).unwrap();
616
617        assert!(result.artifact_id.starts_with("art_"));
618
619        let vr = verifier.verify(&result.envelope).unwrap();
620        assert_eq!(vr.artifact_id, result.artifact_id);
621
622        // Decode and check the payload survived serialization
623        let decoded: DecisionStatement = result.envelope.unmarshal_statement().unwrap();
624        assert_eq!(decoded.actor, "agent://analyst");
625        assert_eq!(decoded.model, Some("claude-opus-4".into()));
626        assert_eq!(decoded.tokens_in, Some(8432));
627        assert_eq!(decoded.tokens_out, Some(1247));
628        assert_eq!(decoded.summary, Some("Contract looks standard.".into()));
629        assert_eq!(decoded.confidence, Some(0.91));
630        assert_eq!(decoded.type_, TYPE_DECISION);
631    }
632
633    #[test]
634    fn different_statement_types_different_ids() {
635        // Action and approval with identical fields but different types
636        // must produce different artifact IDs — enforced by payloadType in PAE.
637        let signer = Ed25519Signer::generate("key_test").unwrap();
638
639        let action   = ActionStatement::new("agent://test", "do.thing");
640        let approval = ApprovalStatement::new("human://test", "nonce_123");
641
642        let r_action   = sign(&payload_type("action"),   &action,   &signer).unwrap();
643        let r_approval = sign(&payload_type("approval"), &approval, &signer).unwrap();
644
645        assert_ne!(r_action.artifact_id, r_approval.artifact_id);
646    }
647
648    #[test]
649    fn timestamp_format() {
650        let ts = unix_to_rfc3339(0);
651        assert_eq!(ts, "1970-01-01T00:00:00Z");
652
653        let ts2 = unix_to_rfc3339(1_000_000_000);
654        assert_eq!(ts2, "2001-09-09T01:46:40Z");
655    }
656}
treeship_core/statements/mod.rs

treeship_core/statements/
mod.rs
