diff --git a/Cargo.lock b/Cargo.lock
index 3ecdc74..1e30f52 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -477,7 +477,6 @@ dependencies = [
  "cultnet-rs",
  "huginn-mind",
  "rmp-serde",
- "schemars",
  "serde",
  "serde_json",
  "sha2",
@@ -491,6 +490,7 @@ name = "huginn-mind"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "base64",
  "chrono",
  "cultcache-rs",
  "cultnet-rs",
diff --git a/crates/huginn-daemon/Cargo.toml b/crates/huginn-daemon/Cargo.toml
index 428588e..5890c67 100644
--- a/crates/huginn-daemon/Cargo.toml
+++ b/crates/huginn-daemon/Cargo.toml
@@ -24,7 +24,6 @@ chrono = "0.4.44"
 cultnet-rs = { git = "https://github.com/GameCult/CultLib.git", rev = "6251cbcd37c12ef3f0c1cc50063a03369225b7ac", package = "cultnet-rs" }
 huginn-mind = { path = "../huginn-mind" }
 rmp-serde = "1"
-schemars = "1"
 serde = { version = "1", features = ["derive"] }
 # The vector store's and the embedder's HTTP APIs are the xenos boundary, and
 # JSON exists in `index/ollama.rs` and `index/qdrant.rs` only. `ureq` 3 with
diff --git a/crates/huginn-daemon/src/lib.rs b/crates/huginn-daemon/src/lib.rs
index a9fbb9f..90ae5e8 100644
--- a/crates/huginn-daemon/src/lib.rs
+++ b/crates/huginn-daemon/src/lib.rs
@@ -1,14 +1,12 @@
 //! `huginn-daemon`: one process that serves one mind over CultNet.
 //!
-//! The crate owns five things and no rule. `startup` owns "may this process
+//! The crate owns four things and no rule. `startup` owns "may this process
 //! serve this mind", by delegating to `Mind::open` and refusing before
 //! anything listens. `index` owns when the mind's documents are embedded and
 //! written to the vector store, off the serving path. `Daemon::handle` owns "which `Mind` method answers this
 //! request": it dispatches, it asks `Mind::require_instance` for every read
-//! that names an instance, and it compares nothing itself. `envelope` owns "is
-//! this a request at all": a message it cannot decode is answered with a typed
-//! failure and touches no mind. `serve` owns "which session gets which reply"
-//! and whether an answer is delivered whole, deferred or refused; `bodies`
+//! that names an instance, and it compares nothing itself. `serve` owns "which
+//! session gets which reply" and whether an answer is delivered whole, deferred or refused; `bodies`
 //! owns how long and how much of a deferred answer is held.
 //!
 //! Every admission rule, the instance check, the receipt, the derived status
@@ -17,7 +15,6 @@
 
 pub mod bodies;
 pub mod daemon;
-pub mod envelope;
 pub mod index;
 pub mod serve;
 
@@ -25,5 +22,4 @@ pub mod serve;
 mod semantic_tests;
 
 pub use daemon::{Daemon, Handled, Hits, IndexSink, Search, SearchTicket, runtime_id};
-pub use envelope::{FAILURE_SCHEMA, OperationFailure};
 pub use serve::{Options, ServeOptions, parse_options, run, startup};
diff --git a/crates/huginn-daemon/src/semantic_tests.rs b/crates/huginn-daemon/src/semantic_tests.rs
index 513f0e9..f72c5b4 100644
--- a/crates/huginn-daemon/src/semantic_tests.rs
+++ b/crates/huginn-daemon/src/semantic_tests.rs
@@ -20,7 +20,7 @@ use tempfile::TempDir;
 
 use crate::daemon::Daemon;
 use crate::daemon::tests::{CAMPAIGN, INSTANCE, batch, campaign_seed, now, slug};
-use crate::envelope::{decode_response, encode_request};
+use huginn_mind::envelope::{decode_response, encode_request};
 use crate::index::fakes::{FakeEmbedder, FakeIndex, Gate};
 use crate::index::{Backoff, Described, Hit, WorkerSink, collection_name};
 use crate::serve::{ServeOptions, bind, run, schema_registry};
diff --git a/crates/huginn-daemon/src/serve.rs b/crates/huginn-daemon/src/serve.rs
index a5efc02..bfc54b8 100644
--- a/crates/huginn-daemon/src/serve.rs
+++ b/crates/huginn-daemon/src/serve.rs
@@ -79,7 +79,7 @@ use crate::bodies::{
     DEFERRED_BUDGET_BYTES, DEFERRED_CHUNK_BYTES, DeferredBodies, MAX_DEFERRED_BODY_BYTES,
 };
 use crate::daemon::{Daemon, Handled, IndexSink, Search, SearchTicket, runtime_id};
-use crate::envelope::{OperationFailure, decode_request, encode_failure, encode_response};
+use huginn_mind::envelope::{OperationFailure, decode_request, encode_failure, encode_response};
 use crate::index::{Backoff, Embedder, VectorIndex, WorkerSink};
 
 /// What the loop does when nothing is waiting. A deferred body untouched for
@@ -345,7 +345,7 @@ fn encode_or_fail(
         Err(error) => encode_failure(
             message_id,
             operation,
-            &crate::envelope::OperationFailure {
+            &OperationFailure {
                 code: "response-not-encodable".into(),
                 message: format!("{error:#}"),
             },
@@ -548,7 +548,7 @@ mod tests {
         open_unindexed, seeded_wide, slug,
     };
     use huginn_mind::epiphany_pipeline::{PipelineKind, PipelineRef};
-    use crate::envelope::{FAILURE_SCHEMA, decode_response, encode_request};
+    use huginn_mind::envelope::{FAILURE_SCHEMA, decode_response, encode_request};
     use crate::index::Backoff;
     use base64::Engine;
     use base64::engine::general_purpose::STANDARD;
@@ -632,7 +632,7 @@ mod tests {
             assert_eq!(rejected(&reply).1, code);
         }
         // The sixth code, `not-an-operation-request`, is the codec's and is
-        // pinned in `envelope::tests`: `answer` never produces it, because a
+        // pinned in `huginn_mind::envelope::tests`: `answer` never produces it, because a
         // message of another family is answered with `Error` instead.
         let reply = answer(&mut daemon, &registry, &mut fresh_bodies(), CultNetMessage::Error { error: "hello".into(), code: None, details: None }, now()).reply();
         let CultNetMessage::Error { error, .. } = &reply else { panic!("expected an error, got {reply:?}") };
diff --git a/crates/huginn-mind/Cargo.toml b/crates/huginn-mind/Cargo.toml
index a2e60d4..ccf4e94 100644
--- a/crates/huginn-mind/Cargo.toml
+++ b/crates/huginn-mind/Cargo.toml
@@ -15,6 +15,7 @@ publish.workspace = true
 # daemon's (Cut 10, Cut 11).
 [dependencies]
 anyhow = "1"
+base64 = "0.22"
 chrono = "0.4.44"
 cultcache-rs = { git = "https://github.com/GameCult/CultLib.git", rev = "6251cbcd37c12ef3f0c1cc50063a03369225b7ac", package = "cultcache-rs" }
 cultnet-rs = { git = "https://github.com/GameCult/CultLib.git", rev = "6251cbcd37c12ef3f0c1cc50063a03369225b7ac", package = "cultnet-rs" }
diff --git a/crates/huginn-daemon/src/envelope.rs b/crates/huginn-mind/src/envelope.rs
similarity index 93%
rename from crates/huginn-daemon/src/envelope.rs
rename to crates/huginn-mind/src/envelope.rs
index fecbde2..8152a54 100644
--- a/crates/huginn-daemon/src/envelope.rs
+++ b/crates/huginn-mind/src/envelope.rs
@@ -14,7 +14,7 @@ use anyhow::Result;
 use base64::Engine;
 use base64::engine::general_purpose::STANDARD;
 use cultnet_rs::CultNetMessage;
-use huginn_mind::wire::{HuginnMindRequest, HuginnMindResponse, MIND_REQUEST_SCHEMA, MIND_RESPONSE_SCHEMA, MIND_SERVICE_ID};
+use crate::wire::{HuginnMindRequest, HuginnMindResponse, MIND_REQUEST_SCHEMA, MIND_RESPONSE_SCHEMA, MIND_SERVICE_ID};
 use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
@@ -151,9 +151,9 @@ pub fn decode_response(message: &CultNetMessage) -> Result<(String, Result<Hugin
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::daemon::tests::{INSTANCE, OTHER, batch, identity, slug};
-    use huginn_mind::wire::MindStatus;
-    use huginn_mind::{MindRefusal, PipelineAdmissionOutcome};
+    use crate::fixtures::{INSTANCE, OTHER_INSTANCE as OTHER, instance, provenance, slug};
+    use crate::wire::MindStatus;
+    use crate::{Faculty, MindRefusal, PipelineAdmissionBatch, PipelineAdmissionOutcome};
 
     fn refusal() -> MindRefusal {
         MindRefusal::ForeignInstance { declared: OTHER.into(), mind: INSTANCE.into() }
@@ -183,7 +183,7 @@ mod tests {
                     schema_epoch: "epiphany.pipeline.epoch.v2".into(),
                     documents: 0,
                     receipts: 0,
-                    index: huginn_mind::wire::IndexStatus::Current,
+                    index: crate::wire::IndexStatus::Current,
                 }),
                 "accepted",
             ),
@@ -214,7 +214,11 @@ mod tests {
     /// `Error` instead.
     #[test]
     fn a_request_round_trips_and_a_foreign_message_is_not_a_request() {
-        let request = HuginnMindRequest::Admit(batch(INSTANCE, vec![identity(INSTANCE)]));
+        let request = HuginnMindRequest::Admit(PipelineAdmissionBatch {
+            instance: slug(INSTANCE),
+            provenance: provenance(Faculty::Hands),
+            documents: vec![instance(INSTANCE)],
+        });
         let message = encode_request("m-3", &request, Some("eureka-state".into())).unwrap();
         assert_eq!(decode_request(&message).unwrap(), ("m-3".into(), request));
 
diff --git a/crates/huginn-mind/src/lib.rs b/crates/huginn-mind/src/lib.rs
index 0fd85e7..b791aac 100644
--- a/crates/huginn-mind/src/lib.rs
+++ b/crates/huginn-mind/src/lib.rs
@@ -14,7 +14,8 @@
 //! selection (CultNet's, over rows this crate supplies) through the same
 //! `docs` the rules use; nothing is stored for it.
 //!
-//! The wire vocabulary is here too, so the daemon and the client share one set
+//! The wire vocabulary and its operation envelope (`envelope`) are here too,
+//! so the daemon and the client share one set
 //! of types.
 //!
 //! Document shape, bounds, formats and keys are `epiphany-pipeline`'s; the
@@ -26,6 +27,7 @@
 
 pub mod admission;
 mod docs;
+pub mod envelope;
 pub mod index;
 pub mod mind;
 mod rows;