What is Agency Receipts, in one sentence?+
The portable, per-action receipt format an agent emits when it acts for a human: a signed, one-sentence-readable record (Ed25519 + JCS) that it happened, optionally hash-chained and linked to the authority it relied on.
What fields does a receipt carry?+
Required: version, receipt_id, issuer_did, principal_did, issued_at, action (category/human_summary/outcome), and signature. Optional: authority_chain, evidence, previous_receipt_hash, jurisdiction, accessibility, and namespace-prefixed extensions. See What is Agency Receipts.
What is the relationship to Agent Envelope (sm-aae)?+
Complementary, not competing. ARP is the human-facing receipt — one-sentence summary, authority chain, per-issuer forward hash chain. AAE is the substrate evidence record — an eight-field, hash-chained pre-action authorization verdict. An ARP receipt's evidence may reference the AAE envelope(s) that substantiate the action. See agentenvelope.ai →.
What is the relationship to sm-dat?+
sm-dat (Delegated Authority Token) is the draft, not-yet-normative companion spec for the principal-signed grant an ARP receipt's authority_chain references. In v0.1, authority_chain is descriptive — a verifier notes it but does not evaluate the grant. DAT normalizes that evaluation in v0.2.
What is the relationship to MCP and A2A?+
ARP sits above both. MCP integrates an agent with tools; A2A moves messages between agents. Neither produces a record the represented human can read, hold, and dispute. ARP records, for the human, the outcome the agent produced through them — it is plumbing-agnostic by design.
Does a receipt prove the action was authorized?+
No. A receipt proves the issuing agent's signed statement that it took an action — not that the principal authorized it, that the authority covered this action, or that the action actually happened at the counterparty. That gap is the explicit subject of the threat model's adversary A1; closing it is the job of the DAT companion spec and, for the authorization verdict itself, of Agent Envelope.
Is Agency Receipts a competitor to Agent Envelope?+
No — complementary. ARP is the human-facing occurrence record; Agent Envelope (sm-aae) is the substrate authorization record. Neither does the other's job: a receipt does not evaluate authorization, and an envelope does not carry a human-readable summary or an authority chain.
What is the conformance badge?+
ARP owns its receipt vectors and conformance criteria; it does not own the signed-badge mechanism itself. That is a generic, protocol-neutral substrate defined by sm-conformance, which ARP imports rather than reimplementing. A conformant runtime ships the badge at .nanda/conformance.json or /.well-known/conformance.json.
Is this open source?+
Yes. sm-arp is MIT-licensed and published-spec-first: the repository at github.com/Sharathvc23 is the canonical source of truth, developed in the open with no external standards-body submission planned for v0.1.