Schemas | Astropods | Documentation

The specification defines the protocol. These schemas define every frame and object on the wire. Where the specification and the JSON Schema disagree, the JSON Schema wins.

JSON Schema

Every frame validates against #/$defs/Frame. Objects such as Task validate against their own definition under $defs. The schema uses JSON Schema 2020-12.

amp.schema.json

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "urn:amp:schema:v0.1",
  "title": "Agent Mesh Protocol (AMP) v0.1",
  "description": "Normative schema for AMP frames and objects. A frame on the wire validates against #/$defs/Frame.",
  "$ref": "#/$defs/Frame",
  "$defs": {
    "Timestamp": { "type": "string", "format": "date-time" },
    "Name": { "type": "string", "pattern": "^[a-z0-9][a-z0-9._-]{0,127}$" },
    "Namespace": { "type": "string", "pattern": "^[a-z0-9][a-z0-9-]{0,62}$" },
    "Address": {
      "type": "string",
      "pattern": "^[a-z0-9][a-z0-9-]{0,62}/[a-z0-9][a-z0-9._-]{0,127}$"
    },
    "Target": {
      "type": "string",
      "pattern": "^(([a-z0-9][a-z0-9-]{0,62}/[a-z0-9][a-z0-9._-]{0,127})|((job|topic):([a-z0-9][a-z0-9-]{0,62}/)?[a-z0-9][a-z0-9._-]{0,127}))$"
    },
    "Metadata": { "type": "object" },
    "Scope": { "type": "string", "pattern": "^[a-z0-9][a-z0-9._-]{0,127}$" },
    "Grant": { "type": "string", "pattern": "^[A-Za-z0-9_-]+\\.[A-Za-z0-9_-]+\\.[A-Za-z0-9_-]+$" },
    "TaskState": {
      "enum": ["submitted", "working", "input-required", "completed", "failed", "canceled", "rejected"]
    },
    "TextPart": {
      "type": "object",
      "required": ["type", "text"],
      "properties": {
        "type": { "const": "text" },
        "text": { "type": "string" },
        "media_type": { "type": "string", "default": "text/plain" }
      }
    },
    "FilePart": {
      "type": "object",
      "required": ["type", "uri"],
      "properties": {
        "type": { "const": "file" },
        "uri": { "type": "string", "format": "uri" },
        "name": { "type": "string" },
        "media_type": { "type": "string" },
        "size_bytes": { "type": "integer", "minimum": 0 },
        "sha256": { "type": "string", "pattern": "^[a-f0-9]{64}$" }
      }
    },
    "DataPart": {
      "type": "object",
      "required": ["type", "data"],
      "properties": {
        "type": { "const": "data" },
        "data": { "type": "object" },
        "schema": { "type": "string", "format": "uri" }
      }
    },
    "Part": {
      "oneOf": [
        { "$ref": "#/$defs/TextPart" },
        { "$ref": "#/$defs/FilePart" },
        { "$ref": "#/$defs/DataPart" }
      ]
    },
    "Job": {
      "type": "object",
      "required": ["name"],
      "properties": {
        "name": { "$ref": "#/$defs/Name" },
        "description": { "type": "string" },
        "input_schema": { "type": "object" },
        "output_schema": { "type": "object" },
        "examples": { "type": "array", "items": { "type": "string" } }
      }
    },
    "Card": {
      "type": "object",
      "required": ["name", "kind"],
      "properties": {
        "name": { "type": "string", "minLength": 1 },
        "description": { "type": "string" },
        "kind": { "enum": ["agent", "human", "gateway"] },
        "jobs": { "type": "array", "items": { "$ref": "#/$defs/Job" } },
        "accepts": {
          "type": "array",
          "items": { "enum": ["text", "file", "data"] },
          "default": ["text"]
        },
        "max_concurrent": { "type": "integer", "minimum": 1, "default": 1 },
        "subscriptions": { "type": "array", "items": { "type": "string" } },
        "metadata": { "$ref": "#/$defs/Metadata" }
      }
    },
    "ArtifactRef": {
      "type": "object",
      "required": ["artifact_id"],
      "properties": {
        "artifact_id": { "type": "string" },
        "name": { "type": "string" },
        "final": { "type": "boolean", "default": true }
      }
    },
    "Trace": {
      "type": "object",
      "required": ["traceparent"],
      "properties": {
        "traceparent": { "type": "string" },
        "tracestate": { "type": "string" }
      }
    },
    "Envelope": {
      "type": "object",
      "required": ["id", "to", "kind"],
      "properties": {
        "id": { "type": "string", "minLength": 1, "maxLength": 128 },
        "from": { "$ref": "#/$defs/Address" },
        "to": { "$ref": "#/$defs/Target" },
        "kind": { "enum": ["message", "task", "status", "event"] },
        "task_id": { "type": "string" },
        "reply_to": { "type": "string" },
        "state": { "$ref": "#/$defs/TaskState" },
        "artifact": { "$ref": "#/$defs/ArtifactRef" },
        "ttl_s": { "type": "integer", "minimum": 1, "maximum": 604800, "default": 3600 },
        "sent_at": { "$ref": "#/$defs/Timestamp" },
        "parts": { "type": "array", "items": { "$ref": "#/$defs/Part" } },
        "trace": { "$ref": "#/$defs/Trace" },
        "scope": { "$ref": "#/$defs/Scope" },
        "metadata": { "$ref": "#/$defs/Metadata" }
      },
      "allOf": [
        {
          "if": { "properties": { "kind": { "const": "status" } } },
          "then": { "required": ["task_id", "state"] },
          "else": { "required": ["parts"], "properties": { "parts": { "minItems": 1 } } }
        },
        {
          "if": { "properties": { "kind": { "const": "event" } } },
          "then": { "properties": { "to": { "pattern": "^topic:" } } }
        }
      ]
    },
    "Status": {
      "type": "object",
      "required": ["state", "at"],
      "properties": {
        "state": { "$ref": "#/$defs/TaskState" },
        "at": { "$ref": "#/$defs/Timestamp" },
        "by": { "$ref": "#/$defs/Address" },
        "message": { "type": "array", "items": { "$ref": "#/$defs/Part" } }
      }
    },
    "Artifact": {
      "type": "object",
      "required": ["artifact_id", "parts"],
      "properties": {
        "artifact_id": { "type": "string" },
        "name": { "type": "string" },
        "parts": { "type": "array", "items": { "$ref": "#/$defs/Part" } },
        "final": { "type": "boolean" }
      }
    },
    "Task": {
      "type": "object",
      "required": ["task_id", "namespace", "requester", "target", "state", "attempt", "max_attempts", "created_at", "updated_at", "expires_at", "history", "artifacts"],
      "properties": {
        "task_id": { "type": "string" },
        "namespace": { "$ref": "#/$defs/Namespace" },
        "requester": { "$ref": "#/$defs/Address" },
        "target": { "$ref": "#/$defs/Target" },
        "scope": { "$ref": "#/$defs/Scope" },
        "assignee": { "oneOf": [{ "$ref": "#/$defs/Address" }, { "type": "null" }] },
        "state": { "$ref": "#/$defs/TaskState" },
        "attempt": { "type": "integer", "minimum": 0 },
        "max_attempts": { "type": "integer", "minimum": 1, "default": 3 },
        "created_at": { "$ref": "#/$defs/Timestamp" },
        "updated_at": { "$ref": "#/$defs/Timestamp" },
        "expires_at": { "$ref": "#/$defs/Timestamp" },
        "history": { "type": "array", "items": { "$ref": "#/$defs/Status" } },
        "artifacts": { "type": "array", "items": { "$ref": "#/$defs/Artifact" } }
      }
    },
    "ErrorCode": {
      "enum": [
        "invalid_frame", "invalid_envelope", "unsupported_version", "unauthenticated", "forbidden",
        "unknown_target", "unsupported_part", "too_large", "rate_limited", "budget_exhausted",
        "task_not_found", "task_final", "lease_lost", "concurrency_limit", "unavailable"
      ]
    },
    "Error": {
      "type": "object",
      "required": ["code", "message", "retryable"],
      "properties": {
        "code": { "$ref": "#/$defs/ErrorCode" },
        "message": { "type": "string" },
        "retryable": { "type": "boolean" },
        "retry_after_s": { "type": "integer", "minimum": 0 }
      }
    },
    "Credential": {
      "type": "object",
      "required": ["kind"],
      "properties": {
        "kind": { "type": "string" },
        "token": { "type": "string" }
      },
      "if": { "properties": { "kind": { "const": "bearer" } } },
      "then": { "required": ["token"] }
    },
    "FrameBase": {
      "type": "object",
      "required": ["type", "seq"],
      "properties": {
        "type": { "type": "string" },
        "seq": { "type": "integer", "minimum": 1 },
        "re": { "type": "integer", "minimum": 1 }
      }
    },
    "Hello": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["versions", "credential", "card"],
      "properties": {
        "type": { "const": "hello" },
        "versions": { "type": "array", "minItems": 1, "items": { "type": "string", "pattern": "^[0-9]+\\.[0-9]+$" } },
        "credential": { "$ref": "#/$defs/Credential" },
        "card": { "$ref": "#/$defs/Card" }
      }
    },
    "Welcome": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["re", "version", "session_id", "address", "heartbeat_interval_s", "limits"],
      "properties": {
        "type": { "const": "welcome" },
        "version": { "type": "string" },
        "session_id": { "type": "string" },
        "address": { "$ref": "#/$defs/Address" },
        "scopes": { "type": "array", "items": { "$ref": "#/$defs/Scope" } },
        "heartbeat_interval_s": { "type": "integer", "minimum": 1 },
        "limits": {
          "type": "object",
          "properties": {
            "max_envelope_bytes": { "type": "integer", "minimum": 1 },
            "max_concurrent_leases": { "type": "integer", "minimum": 1 },
            "lease_s": { "type": "integer", "minimum": 1 },
            "ack_wait_s": { "type": "integer", "minimum": 1 },
            "grant_s": { "type": "integer", "minimum": 1 }
          }
        }
      }
    },
    "Send": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["envelope"],
      "properties": { "type": { "const": "send" }, "envelope": { "$ref": "#/$defs/Envelope" } }
    },
    "Accepted": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["re", "id"],
      "properties": { "type": { "const": "accepted" }, "id": { "type": "string" }, "task_id": { "type": "string" } }
    },
    "Deliver": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["delivery_id", "envelope"],
      "properties": {
        "type": { "const": "deliver" },
        "delivery_id": { "type": "string" },
        "envelope": { "$ref": "#/$defs/Envelope" },
        "offer": { "type": "boolean", "description": "True when the envelope is a task offered for claiming" },
        "grant": { "$ref": "#/$defs/Grant" }
      }
    },
    "Ack": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["delivery_id"],
      "properties": { "type": { "const": "ack" }, "delivery_id": { "type": "string" } }
    },
    "Nack": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["delivery_id"],
      "properties": {
        "type": { "const": "nack" },
        "delivery_id": { "type": "string" },
        "delay_s": { "type": "integer", "minimum": 0 }
      }
    },
    "Claim": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["task_id"],
      "properties": { "type": { "const": "claim" }, "task_id": { "type": "string" } }
    },
    "Granted": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["task_id", "lease_id", "expires_at"],
      "properties": {
        "type": { "const": "granted" },
        "task_id": { "type": "string" },
        "lease_id": { "type": "string" },
        "expires_at": { "$ref": "#/$defs/Timestamp" },
        "grant": { "$ref": "#/$defs/Grant" }
      }
    },
    "Heartbeat": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "properties": { "type": { "const": "heartbeat" } }
    },
    "Release": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["task_id"],
      "properties": { "type": { "const": "release" }, "task_id": { "type": "string" } }
    },
    "Subscribe": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["topic"],
      "properties": {
        "type": { "const": "subscribe" },
        "topic": { "$ref": "#/$defs/Target" },
        "from": { "type": "string", "description": "Replay start: a timestamp or a stream sequence" }
      }
    },
    "Unsubscribe": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["topic"],
      "properties": { "type": { "const": "unsubscribe" }, "topic": { "$ref": "#/$defs/Target" } }
    },
    "Query": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "properties": {
        "type": { "const": "query" },
        "task": { "type": "string" },
        "job": { "$ref": "#/$defs/Name" },
        "participant": { "$ref": "#/$defs/Address" }
      },
      "oneOf": [{ "required": ["task"] }, { "required": ["job"] }, { "required": ["participant"] }]
    },
    "Result": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["re"],
      "properties": {
        "type": { "const": "result" },
        "task": { "$ref": "#/$defs/Task" },
        "participants": {
          "type": "array",
          "items": {
            "type": "object",
            "required": ["address", "card"],
            "properties": { "address": { "$ref": "#/$defs/Address" }, "card": { "$ref": "#/$defs/Card" } }
          }
        }
      }
    },
    "ErrorFrame": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "required": ["error"],
      "properties": { "type": { "const": "error" }, "error": { "$ref": "#/$defs/Error" } }
    },
    "Goodbye": {
      "allOf": [{ "$ref": "#/$defs/FrameBase" }],
      "properties": { "type": { "const": "goodbye" }, "reason": { "type": "string" } }
    },
    "Frame": {
      "oneOf": [
        { "$ref": "#/$defs/Hello" }, { "$ref": "#/$defs/Welcome" }, { "$ref": "#/$defs/Send" },
        { "$ref": "#/$defs/Accepted" }, { "$ref": "#/$defs/Deliver" }, { "$ref": "#/$defs/Ack" },
        { "$ref": "#/$defs/Nack" }, { "$ref": "#/$defs/Claim" }, { "$ref": "#/$defs/Granted" },
        { "$ref": "#/$defs/Heartbeat" }, { "$ref": "#/$defs/Release" }, { "$ref": "#/$defs/Subscribe" },
        { "$ref": "#/$defs/Unsubscribe" }, { "$ref": "#/$defs/Query" }, { "$ref": "#/$defs/Result" },
        { "$ref": "#/$defs/ErrorFrame" }, { "$ref": "#/$defs/Goodbye" }
      ]
    }
  }
}

Protocol Buffers

The gRPC binding uses one bidirectional stream, amp.v1alpha1.BrokerService/Session. Each stream message wraps one frame.

amp.proto

syntax = "proto3";
package amp.v1alpha1;
import "google/protobuf/struct.proto";
import "google/protobuf/timestamp.proto";
option go_package = "ampv1alpha1";
service BrokerService {
  rpc Session(stream SessionRequest) returns (stream SessionResponse);
}
message SessionRequest {
  Frame frame = 1;
}
message SessionResponse {
  Frame frame = 1;
}
message Frame {
  uint64 seq = 1;
  uint64 re = 2;
  oneof body {
    Hello hello = 10;
    Welcome welcome = 11;
    Send send = 12;
    Accepted accepted = 13;
    Deliver deliver = 14;
    Ack ack = 15;
    Nack nack = 16;
    Claim claim = 17;
    Granted granted = 18;
    Heartbeat heartbeat = 19;
    Release release = 20;
    Subscribe subscribe = 21;
    Unsubscribe unsubscribe = 22;
    Query query = 23;
    Result result = 24;
    Error error = 25;
    Goodbye goodbye = 26;
  }
}
message Hello {
  repeated string versions = 1;
  Credential credential = 2;
  Card card = 3;
}
message Credential {
  string kind = 1;
  string token = 2;
}
message Welcome {
  string version = 1;
  string session_id = 2;
  string address = 3;
  uint32 heartbeat_interval_s = 4;
  Limits limits = 5;
}
message Limits {
  uint64 max_envelope_bytes = 1;
  uint32 max_concurrent_leases = 2;
  uint32 lease_s = 3;
  uint32 ack_wait_s = 4;
}
message Send {
  Envelope envelope = 1;
}
message Accepted {
  string id = 1;
  string task_id = 2;
}
message Deliver {
  string delivery_id = 1;
  Envelope envelope = 2;
  bool offer = 3;
}
message Ack {
  string delivery_id = 1;
}
message Nack {
  string delivery_id = 1;
  uint32 delay_s = 2;
}
message Claim {
  string task_id = 1;
}
message Granted {
  string task_id = 1;
  string lease_id = 2;
  google.protobuf.Timestamp expires_at = 3;
}
message Heartbeat {}
message Release {
  string task_id = 1;
}
message Subscribe {
  string topic = 1;
  string from = 2;
}
message Unsubscribe {
  string topic = 1;
}
message Query {
  oneof target {
    string task = 1;
    string job = 2;
    string participant = 3;
  }
}
message Result {
  Task task = 1;
  repeated Registration participants = 2;
}
message Registration {
  string address = 1;
  Card card = 2;
}
message Goodbye {
  string reason = 1;
}
enum Kind {
  KIND_UNSPECIFIED = 0;
  KIND_MESSAGE = 1;
  KIND_TASK = 2;
  KIND_STATUS = 3;
  KIND_EVENT = 4;
}
enum TaskState {
  TASK_STATE_UNSPECIFIED = 0;
  TASK_STATE_SUBMITTED = 1;
  TASK_STATE_WORKING = 2;
  TASK_STATE_INPUT_REQUIRED = 3;
  TASK_STATE_COMPLETED = 4;
  TASK_STATE_FAILED = 5;
  TASK_STATE_CANCELED = 6;
  TASK_STATE_REJECTED = 7;
}
message Envelope {
  string id = 1;
  string from = 2;
  string to = 3;
  Kind kind = 4;
  string task_id = 5;
  string reply_to = 6;
  TaskState state = 7;
  ArtifactRef artifact = 8;
  uint32 ttl_s = 9;
  google.protobuf.Timestamp sent_at = 10;
  repeated Part parts = 11;
  Trace trace = 12;
  google.protobuf.Struct metadata = 13;
}
message ArtifactRef {
  string artifact_id = 1;
  string name = 2;
  bool final = 3;
}
message Trace {
  string traceparent = 1;
  string tracestate = 2;
}
message Part {
  oneof part {
    TextPart text = 1;
    FilePart file = 2;
    DataPart data = 3;
  }
}
message TextPart {
  string text = 1;
  string media_type = 2;
}
message FilePart {
  string uri = 1;
  string name = 2;
  string media_type = 3;
  uint64 size_bytes = 4;
  string sha256 = 5;
}
message DataPart {
  google.protobuf.Struct data = 1;
  string schema = 2;
}
message Card {
  string name = 1;
  string description = 2;
  string kind = 3;
  repeated Job jobs = 4;
  repeated string accepts = 5;
  uint32 max_concurrent = 6;
  repeated string subscriptions = 7;
  google.protobuf.Struct metadata = 8;
}
message Job {
  string name = 1;
  string description = 2;
  google.protobuf.Struct input_schema = 3;
  google.protobuf.Struct output_schema = 4;
  repeated string examples = 5;
}
message Status {
  TaskState state = 1;
  google.protobuf.Timestamp at = 2;
  string by = 3;
  repeated Part message = 4;
}
message Artifact {
  string artifact_id = 1;
  string name = 2;
  repeated Part parts = 3;
  bool final = 4;
}
message Task {
  string task_id = 1;
  string namespace = 2;
  string requester = 3;
  string target = 4;
  string assignee = 5;
  TaskState state = 6;
  uint32 attempt = 7;
  uint32 max_attempts = 8;
  google.protobuf.Timestamp created_at = 9;
  google.protobuf.Timestamp updated_at = 10;
  google.protobuf.Timestamp expires_at = 11;
  repeated Status history = 12;
  repeated Artifact artifacts = 13;
}
message Error {
  string code = 1;
  string message = 2;
  bool retryable = 3;
  uint32 retry_after_s = 4;
}

Examples

Each example validates against the JSON Schema.

hello.json

{
  "type": "hello",
  "seq": 1,
  "versions": ["0.1"],
  "credential": { "kind": "bearer", "token": "eyJhbGciOi..." },
  "card": {
    "name": "Writer",
    "kind": "agent",
    "description": "Writes summaries and briefs",
    "jobs": [
      {
        "name": "summarize",
        "description": "Summarize documents into a short brief",
        "input_schema": { "type": "object", "properties": { "max_words": { "type": "integer" } } }
      }
    ],
    "accepts": ["text", "file", "data"],
    "max_concurrent": 2,
    "subscriptions": ["topic:documents"]
  }
}

welcome.json

{
  "type": "welcome",
  "seq": 1,
  "re": 1,
  "version": "0.1",
  "session_id": "s_7h2k",
  "address": "acme/writer",
  "heartbeat_interval_s": 10,
  "limits": { "max_envelope_bytes": 1048576, "max_concurrent_leases": 2, "lease_s": 60, "ack_wait_s": 30 }
}

send-task.json

{
  "type": "send",
  "seq": 2,
  "envelope": {
    "id": "01J9Z6QK3X8M2V4N5P6R7S8T9U",
    "to": "job:summarize",
    "kind": "task",
    "ttl_s": 3600,
    "parts": [
      { "type": "text", "text": "Summarize the Q3 customer interviews for the board" },
      { "type": "file", "uri": "https://files.example.com/q3-interviews.pdf", "name": "q3-interviews.pdf", "media_type": "application/pdf" },
      { "type": "data", "data": { "max_words": 300 } }
    ],
    "trace": { "traceparent": "00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01" }
  }
}

deliver-offer.json

{
  "type": "deliver",
  "seq": 5,
  "delivery_id": "d_19",
  "offer": true,
  "envelope": {
    "id": "01J9Z6QK3X8M2V4N5P6R7S8T9U",
    "from": "acme/analyst",
    "to": "job:summarize",
    "kind": "task",
    "task_id": "t_41",
    "sent_at": "2026-10-02T10:00:00Z",
    "parts": [{ "type": "text", "text": "Summarize the Q3 customer interviews for the board" }]
  }
}

status-completed.json

{
  "type": "send",
  "seq": 9,
  "envelope": {
    "id": "01J9Z6S2B5C7D9F1G3H5J7K9L1",
    "to": "acme/analyst",
    "kind": "status",
    "task_id": "t_41",
    "state": "completed",
    "artifact": { "artifact_id": "a_1", "name": "board-brief.md", "final": true },
    "parts": [{ "type": "text", "text": "## Q3 interviews\n\nCustomers asked for...", "media_type": "text/markdown" }]
  }
}

error-rate-limited.json

{
  "type": "error",
  "seq": 4,
  "re": 3,
  "error": { "code": "rate_limited", "message": "60 tasks per minute exceeded", "retryable": true, "retry_after_s": 12 }
}

task.json

{
  "task_id": "t_41",
  "namespace": "acme",
  "requester": "acme/analyst",
  "target": "job:summarize",
  "assignee": "acme/writer",
  "state": "completed",
  "attempt": 1,
  "max_attempts": 3,
  "created_at": "2026-10-02T10:00:00Z",
  "updated_at": "2026-10-02T10:02:10Z",
  "expires_at": "2026-10-02T11:00:00Z",
  "history": [
    { "state": "submitted", "at": "2026-10-02T10:00:00Z", "by": "acme/analyst" },
    { "state": "working", "at": "2026-10-02T10:00:01Z", "by": "acme/writer" },
    { "state": "completed", "at": "2026-10-02T10:02:10Z", "by": "acme/writer" }
  ],
  "artifacts": [
    { "artifact_id": "a_1", "name": "board-brief.md", "final": true, "parts": [{ "type": "text", "text": "## Q3 interviews", "media_type": "text/markdown" }] }
  ]
}

Scopes and grants

These frames come from a broker that partitions namespaces into scopes. Each grant is a placeholder: its signature is not valid.

welcome-scoped.json

{
  "type": "welcome",
  "seq": 1,
  "re": 1,
  "version": "0.1",
  "session_id": "s_9m3p",
  "address": "acme/analyst",
  "scopes": [
    "research",
    "sales"
  ],
  "heartbeat_interval_s": 10,
  "limits": {
    "max_envelope_bytes": 1048576,
    "max_concurrent_leases": 4,
    "lease_s": 60,
    "ack_wait_s": 30,
    "grant_s": 300
  }
}

send-task-scoped.json

{
  "type": "send",
  "seq": 3,
  "envelope": {
    "id": "01J9Z6R2B7C4D5E6F7G8H9J0KM",
    "to": "acme/writer",
    "kind": "task",
    "scope": "research",
    "parts": [
      {
        "type": "text",
        "text": "Draft the Q3 research summary"
      }
    ]
  }
}

granted-with-grant.json

{
  "type": "granted",
  "seq": 9,
  "re": 4,
  "task_id": "t_3f9a1c22b8d47e5a6b10",
  "lease_id": "l_7c1",
  "expires_at": "2026-10-05T10:01:00Z",
  "grant": "eyJhbGciOiJFZERTQSIsInR5cCI6ImFtcC1ncmFudCtqd3QiLCJraWQiOiJrMSJ9.eyJpc3MiOiJodHRwczovL21lc2guZXhhbXBsZS5jb20iLCJhdWQiOiJodHRwczovL2RvY3MuZXhhbXBsZS5jb20iLCJzdWIiOiJhY21lL3dyaXRlciIsInNjb3BlIjoicmVzZWFyY2giLCJpYXQiOjE3OTE1NDAwMDAsImV4cCI6MTc5MTU0MDMwMCwidGFza19pZCI6InRfM2Y5YTFjMjJiOGQ0N2U1YTZiMTAifQ.AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4vMDEyMzQ1Njc4OTo7PD0-Pw"
}

deliver-message-scoped.json

{
  "type": "deliver",
  "seq": 11,
  "delivery_id": "d_42",
  "envelope": {
    "id": "01J9Z6T7E2G3H4J5K6L7M8N9PQ",
    "from": "acme/analyst",
    "to": "acme/writer",
    "kind": "message",
    "scope": "research",
    "sent_at": "2026-10-05T10:00:05Z",
    "parts": [
      {
        "type": "text",
        "text": "Which interview had the pricing complaint?"
      }
    ]
  },
  "grant": "eyJhbGciOiJFZERTQSIsInR5cCI6ImFtcC1ncmFudCtqd3QiLCJraWQiOiJrMSJ9.eyJpc3MiOiJodHRwczovL21lc2guZXhhbXBsZS5jb20iLCJhdWQiOiJodHRwczovL2RvY3MuZXhhbXBsZS5jb20iLCJzdWIiOiJhY21lL3dyaXRlciIsInNjb3BlIjoicmVzZWFyY2giLCJpYXQiOjE3OTE1NDAwMDAsImV4cCI6MTc5MTU0MDMwMCwibWVzc2FnZV9pZCI6IjAxSjlaNlQ3RTJHM0g0SjVLNkw3TThOOVBRIn0.AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIjJCUmJygpKissLS4vMDEyMzQ1Njc4OTo7PD0-Pw"
}

Next steps

Specification: the rules these schemas encode
NATS JetStream binding: build a broker on NATS