diff --git a/Cargo.lock b/Cargo.lock
index 84998d22ca..76795c8cfb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1971,6 +1971,37 @@ version = "4.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d211803b9b6b570f68772237e415a029d5a50c65d382910b879fb19d3271f94d"
 
+[[package]]
+name = "pacquet-catalogs-config"
+version = "0.0.1"
+dependencies = [
+ "derive_more",
+ "miette 7.6.0",
+ "pacquet-catalogs-types",
+ "pacquet-workspace",
+]
+
+[[package]]
+name = "pacquet-catalogs-protocol-parser"
+version = "0.0.1"
+dependencies = [
+ "pacquet-catalogs-types",
+]
+
+[[package]]
+name = "pacquet-catalogs-resolver"
+version = "0.0.1"
+dependencies = [
+ "derive_more",
+ "miette 7.6.0",
+ "pacquet-catalogs-protocol-parser",
+ "pacquet-catalogs-types",
+]
+
+[[package]]
+name = "pacquet-catalogs-types"
+version = "0.0.1"
+
 [[package]]
 name = "pacquet-cli"
 version = "0.0.1"
@@ -2366,6 +2397,8 @@ dependencies = [
  "insta",
  "miette 7.6.0",
  "node-semver",
+ "pacquet-catalogs-config",
+ "pacquet-catalogs-types",
  "pacquet-cmd-shim",
  "pacquet-config",
  "pacquet-crypto-hash",
@@ -2527,6 +2560,8 @@ dependencies = [
  "futures-util",
  "miette 7.6.0",
  "node-semver",
+ "pacquet-catalogs-resolver",
+ "pacquet-catalogs-types",
  "pacquet-deps-path",
  "pacquet-lockfile",
  "pacquet-package-manifest",
@@ -2719,6 +2754,7 @@ version = "0.0.1"
 dependencies = [
  "derive_more",
  "miette 7.6.0",
+ "pacquet-catalogs-types",
  "pacquet-package-manifest",
  "pretty_assertions",
  "serde",
diff --git a/Cargo.toml b/Cargo.toml
index 8257b6ca98..12bdc5d1eb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,6 +13,10 @@ repository  = "https://github.com/pnpm/pacquet"
 
 [workspace.dependencies]
 # Crates
+pacquet-catalogs-config                   = { path = "pacquet/crates/catalogs-config" }
+pacquet-catalogs-protocol-parser          = { path = "pacquet/crates/catalogs-protocol-parser" }
+pacquet-catalogs-resolver                 = { path = "pacquet/crates/catalogs-resolver" }
+pacquet-catalogs-types                    = { path = "pacquet/crates/catalogs-types" }
 pacquet-cli                               = { path = "pacquet/crates/cli" }
 pacquet-cmd-shim                          = { path = "pacquet/crates/cmd-shim" }
 pacquet-crypto-hash                       = { path = "pacquet/crates/crypto-hash" }
diff --git a/pacquet/crates/catalogs-config/Cargo.toml b/pacquet/crates/catalogs-config/Cargo.toml
new file mode 100644
index 0000000000..e38e971507
--- /dev/null
+++ b/pacquet/crates/catalogs-config/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name                  = "pacquet-catalogs-config"
+version               = "0.0.1"
+publish               = false
+authors.workspace     = true
+description.workspace = true
+edition.workspace     = true
+homepage.workspace    = true
+keywords.workspace    = true
+license.workspace     = true
+repository.workspace  = true
+
+[dependencies]
+pacquet-catalogs-types = { workspace = true }
+pacquet-workspace      = { workspace = true }
+
+derive_more = { workspace = true }
+miette      = { workspace = true }
+
+[lints]
+workspace = true
diff --git a/pacquet/crates/catalogs-config/src/lib.rs b/pacquet/crates/catalogs-config/src/lib.rs
new file mode 100644
index 0000000000..2c562bfddf
--- /dev/null
+++ b/pacquet/crates/catalogs-config/src/lib.rs
@@ -0,0 +1,81 @@
+//! Pacquet port of pnpm's
+//! [`@pnpm/catalogs.config`](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/config/src/getCatalogsFromWorkspaceManifest.ts).
+//!
+//! Normalizes the two surface forms `pnpm-workspace.yaml` supports for
+//! defining the default catalog — `catalog:` at the top level vs.
+//! `catalogs.default` nested under the named catalogs — into the
+//! single flat [`Catalogs`] map every resolver consumer expects.
+
+use derive_more::{Display, Error};
+use miette::Diagnostic;
+use pacquet_catalogs_types::{Catalogs, DEFAULT_CATALOG_NAME};
+use pacquet_workspace::WorkspaceManifest;
+
+/// Raised when the workspace manifest defines the default catalog
+/// twice — once via the top-level `catalog:` shorthand and once via
+/// the explicit `catalogs.default` key.
+///
+/// Mirrors upstream's `INVALID_CATALOGS_CONFIGURATION` `PnpmError`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/config/src/getCatalogsFromWorkspaceManifest.ts#L32-L37)).
+#[derive(Debug, Display, Error, Diagnostic, Clone, PartialEq, Eq)]
+#[non_exhaustive]
+pub enum InvalidCatalogsConfigurationError {
+    #[display(
+        "The 'default' catalog was defined multiple times. Use the 'catalog' field or 'catalogs.default', but not both."
+    )]
+    #[diagnostic(code(ERR_PNPM_INVALID_CATALOGS_CONFIGURATION))]
+    DefaultDefinedMultipleTimes,
+}
+
+/// Project the catalog-shaped fields from a parsed workspace manifest
+/// into a single flat [`Catalogs`] map.
+///
+/// Returns an empty map when `workspace_manifest` is `None`, matching
+/// the upstream "no workspace manifest → no catalogs" branch.
+///
+/// Mirrors upstream's `getCatalogsFromWorkspaceManifest`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/config/src/getCatalogsFromWorkspaceManifest.ts#L5-L30)).
+pub fn get_catalogs_from_workspace_manifest(
+    workspace_manifest: Option<&WorkspaceManifest>,
+) -> Result<Catalogs, InvalidCatalogsConfigurationError> {
+    let Some(manifest) = workspace_manifest else {
+        return Ok(Catalogs::new());
+    };
+
+    check_default_catalog_is_defined_once(manifest)?;
+
+    // Upstream spreads `workspace.catalogs` after writing `default`, so
+    // an explicit `catalogs.default` overrides the (already-validated
+    // to be absent) `catalog` field. With `catalog`/`catalogs.default`
+    // mutually exclusive only one branch ever populates the key.
+    let mut catalogs = Catalogs::new();
+    if let Some(default) = &manifest.catalog {
+        catalogs.insert(DEFAULT_CATALOG_NAME.to_string(), default.clone());
+    }
+    if let Some(named) = &manifest.catalogs {
+        for (name, catalog) in named {
+            catalogs.insert(name.clone(), catalog.clone());
+        }
+    }
+
+    Ok(catalogs)
+}
+
+/// Validate that the default catalog is defined through at most one of
+/// the two surface forms.
+///
+/// Mirrors upstream's `checkDefaultCatalogIsDefinedOnce`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/config/src/getCatalogsFromWorkspaceManifest.ts#L32-L40)).
+pub fn check_default_catalog_is_defined_once(
+    manifest: &WorkspaceManifest,
+) -> Result<(), InvalidCatalogsConfigurationError> {
+    if manifest.catalog.is_some()
+        && manifest.catalogs.as_ref().is_some_and(|c| c.contains_key(DEFAULT_CATALOG_NAME))
+    {
+        return Err(InvalidCatalogsConfigurationError::DefaultDefinedMultipleTimes);
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests;
diff --git a/pacquet/crates/catalogs-config/src/tests.rs b/pacquet/crates/catalogs-config/src/tests.rs
new file mode 100644
index 0000000000..958c1e8d84
--- /dev/null
+++ b/pacquet/crates/catalogs-config/src/tests.rs
@@ -0,0 +1,68 @@
+//! Ports of `catalogs/config/test/getCatalogsFromWorkspaceManifest.test.ts`
+//! ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/config/test/getCatalogsFromWorkspaceManifest.test.ts)).
+
+use super::{InvalidCatalogsConfigurationError, get_catalogs_from_workspace_manifest};
+use pacquet_catalogs_types::{Catalog, Catalogs};
+use pacquet_workspace::WorkspaceManifest;
+
+fn catalog_from(entries: &[(&str, &str)]) -> Catalog {
+    entries.iter().map(|(k, v)| ((*k).to_string(), (*v).to_string())).collect()
+}
+
+#[test]
+fn combines_implicit_default_and_named_catalogs() {
+    let manifest = WorkspaceManifest {
+        catalog: Some(catalog_from(&[("foo", "^1.0.0")])),
+        catalogs: Some(Catalogs::from([("bar".to_string(), catalog_from(&[("baz", "^2.0.0")]))])),
+        ..WorkspaceManifest::default()
+    };
+
+    let expected = Catalogs::from([
+        ("default".to_string(), catalog_from(&[("foo", "^1.0.0")])),
+        ("bar".to_string(), catalog_from(&[("baz", "^2.0.0")])),
+    ]);
+    assert_eq!(get_catalogs_from_workspace_manifest(Some(&manifest)).unwrap(), expected);
+}
+
+#[test]
+fn combines_explicit_default_and_named_catalogs() {
+    let manifest = WorkspaceManifest {
+        catalog: None,
+        catalogs: Some(Catalogs::from([
+            ("default".to_string(), catalog_from(&[("foo", "^1.0.0")])),
+            ("bar".to_string(), catalog_from(&[("baz", "^2.0.0")])),
+        ])),
+        ..WorkspaceManifest::default()
+    };
+
+    let expected = Catalogs::from([
+        ("default".to_string(), catalog_from(&[("foo", "^1.0.0")])),
+        ("bar".to_string(), catalog_from(&[("baz", "^2.0.0")])),
+    ]);
+    assert_eq!(get_catalogs_from_workspace_manifest(Some(&manifest)).unwrap(), expected);
+}
+
+#[test]
+fn throws_if_default_catalog_is_defined_multiple_times() {
+    let manifest = WorkspaceManifest {
+        catalog: Some(catalog_from(&[("bar", "^2.0.0")])),
+        catalogs: Some(Catalogs::from([(
+            "default".to_string(),
+            catalog_from(&[("foo", "^1.0.0")]),
+        )])),
+        ..WorkspaceManifest::default()
+    };
+
+    let err = get_catalogs_from_workspace_manifest(Some(&manifest)).unwrap_err();
+    assert_eq!(err, InvalidCatalogsConfigurationError::DefaultDefinedMultipleTimes);
+    assert_eq!(
+        err.to_string(),
+        "The 'default' catalog was defined multiple times. \
+         Use the 'catalog' field or 'catalogs.default', but not both.",
+    );
+}
+
+#[test]
+fn returns_empty_map_for_missing_workspace_manifest() {
+    assert_eq!(get_catalogs_from_workspace_manifest(None).unwrap(), Catalogs::new());
+}
diff --git a/pacquet/crates/catalogs-protocol-parser/Cargo.toml b/pacquet/crates/catalogs-protocol-parser/Cargo.toml
new file mode 100644
index 0000000000..a519fdb248
--- /dev/null
+++ b/pacquet/crates/catalogs-protocol-parser/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name                  = "pacquet-catalogs-protocol-parser"
+version               = "0.0.1"
+publish               = false
+authors.workspace     = true
+description.workspace = true
+edition.workspace     = true
+homepage.workspace    = true
+keywords.workspace    = true
+license.workspace     = true
+repository.workspace  = true
+
+[dependencies]
+pacquet-catalogs-types = { workspace = true }
+
+[lints]
+workspace = true
diff --git a/pacquet/crates/catalogs-protocol-parser/src/lib.rs b/pacquet/crates/catalogs-protocol-parser/src/lib.rs
new file mode 100644
index 0000000000..84ccc690ba
--- /dev/null
+++ b/pacquet/crates/catalogs-protocol-parser/src/lib.rs
@@ -0,0 +1,27 @@
+//! Pacquet port of pnpm's
+//! [`@pnpm/catalogs.protocol-parser`](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/protocol-parser/src/parseCatalogProtocol.ts).
+//!
+//! Splits the `catalog:` protocol prefix off a manifest bare specifier
+//! and returns the requested catalog name. Used by the resolver chain
+//! to decide whether a wanted dependency should be looked up in a
+//! catalog before falling through to the npm / git / tarball resolvers.
+
+use pacquet_catalogs_types::DEFAULT_CATALOG_NAME;
+
+const CATALOG_PROTOCOL: &str = "catalog:";
+
+/// Parse a package.json dependency specifier using the `catalog:`
+/// protocol.
+///
+/// Returns `None` if the specifier does not start with `catalog:`.
+/// An empty `catalog:` is shorthand for [`DEFAULT_CATALOG_NAME`].
+///
+/// Mirrors upstream's `parseCatalogProtocol`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/protocol-parser/src/parseCatalogProtocol.ts#L3-L16)).
+pub fn parse_catalog_protocol(bare_specifier: &str) -> Option<&str> {
+    let raw = bare_specifier.strip_prefix(CATALOG_PROTOCOL)?.trim();
+    Some(if raw.is_empty() { DEFAULT_CATALOG_NAME } else { raw })
+}
+
+#[cfg(test)]
+mod tests;
diff --git a/pacquet/crates/catalogs-protocol-parser/src/tests.rs b/pacquet/crates/catalogs-protocol-parser/src/tests.rs
new file mode 100644
index 0000000000..2121f25912
--- /dev/null
+++ b/pacquet/crates/catalogs-protocol-parser/src/tests.rs
@@ -0,0 +1,25 @@
+//! Ports of `catalogs/protocol-parser/test/parseCatalogProtocol.test.ts`
+//! ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/protocol-parser/test/parseCatalogProtocol.test.ts)).
+
+use super::parse_catalog_protocol;
+
+#[test]
+fn parses_named_catalog() {
+    assert_eq!(parse_catalog_protocol("catalog:foo"), Some("foo"));
+    assert_eq!(parse_catalog_protocol("catalog:bar"), Some("bar"));
+}
+
+#[test]
+fn returns_none_for_specifier_not_using_catalog_protocol() {
+    assert_eq!(parse_catalog_protocol("^1.0.0"), None);
+}
+
+#[test]
+fn parses_explicit_default_catalog() {
+    assert_eq!(parse_catalog_protocol("catalog:default"), Some("default"));
+}
+
+#[test]
+fn parses_implicit_default_catalog() {
+    assert_eq!(parse_catalog_protocol("catalog:"), Some("default"));
+}
diff --git a/pacquet/crates/catalogs-resolver/Cargo.toml b/pacquet/crates/catalogs-resolver/Cargo.toml
new file mode 100644
index 0000000000..b7466c473d
--- /dev/null
+++ b/pacquet/crates/catalogs-resolver/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name                  = "pacquet-catalogs-resolver"
+version               = "0.0.1"
+publish               = false
+authors.workspace     = true
+description.workspace = true
+edition.workspace     = true
+homepage.workspace    = true
+keywords.workspace    = true
+license.workspace     = true
+repository.workspace  = true
+
+[dependencies]
+pacquet-catalogs-protocol-parser = { workspace = true }
+pacquet-catalogs-types           = { workspace = true }
+
+derive_more = { workspace = true }
+miette      = { workspace = true }
+
+[lints]
+workspace = true
diff --git a/pacquet/crates/catalogs-resolver/src/lib.rs b/pacquet/crates/catalogs-resolver/src/lib.rs
new file mode 100644
index 0000000000..e34e5462d2
--- /dev/null
+++ b/pacquet/crates/catalogs-resolver/src/lib.rs
@@ -0,0 +1,184 @@
+//! Pacquet port of pnpm's
+//! [`@pnpm/catalogs.resolver`](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts).
+//!
+//! Dereferences a `catalog:` bare specifier against a parsed
+//! [`Catalogs`] map and returns either the configured version or one of
+//! the upstream misconfiguration errors. The npm-resolver chain calls
+//! [`resolve_from_catalog`] before its own protocol dispatch so a
+//! resolved [`CatalogResolutionFound::resolution`] feeds back in as a
+//! plain bare specifier.
+
+use derive_more::{Display, Error};
+use miette::Diagnostic;
+use pacquet_catalogs_protocol_parser::parse_catalog_protocol;
+use pacquet_catalogs_types::Catalogs;
+
+/// Subset of `pacquet-resolving-resolver-base`'s `WantedDependency`
+/// that catalog resolution needs. Modeled as its own type so this
+/// crate doesn't depend on the resolver-base crate; the conversion
+/// is a trivial field copy at the call site.
+///
+/// Mirrors upstream's `WantedDependency` interface
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L5-L8)).
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct WantedDependency {
+    pub alias: String,
+    pub bare_specifier: String,
+}
+
+/// Outcome of [`resolve_from_catalog`].
+///
+/// Mirrors upstream's `CatalogResolutionResult` discriminated union
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L19)).
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum CatalogResolutionResult {
+    /// The catalog protocol resolved to a usable specifier.
+    Found(CatalogResolutionFound),
+    /// The catalog entry was missing or used a forbidden protocol.
+    Misconfiguration(CatalogResolutionMisconfiguration),
+    /// The wanted dependency does not use the catalog protocol.
+    Unused,
+}
+
+/// Successful catalog dereference.
+///
+/// Mirrors upstream's `CatalogResolutionFound`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L21-L24)).
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CatalogResolutionFound {
+    pub resolution: CatalogResolution,
+}
+
+/// Resolved (catalog name, specifier) pair.
+///
+/// Mirrors upstream's `CatalogResolution`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L26-L38)).
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CatalogResolution {
+    /// Catalog the entry was found in.
+    pub catalog_name: String,
+    /// Version specifier the catalog entry resolved to.
+    pub specifier: String,
+}
+
+/// A user-misconfigured catalog entry. Carries the error so the call
+/// site can rethrow or render it.
+///
+/// Mirrors upstream's `CatalogResolutionMisconfiguration`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L40-L52)).
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CatalogResolutionMisconfiguration {
+    pub catalog_name: String,
+    pub error: CatalogResolutionError,
+}
+
+/// The four ways a `catalog:` lookup can fail. Each variant maps
+/// byte-for-byte to the upstream `PnpmError` code.
+///
+/// Mirrors the four errors raised by upstream's `resolveFromCatalog`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L60-L120)).
+#[derive(Debug, Display, Error, Diagnostic, Clone, PartialEq, Eq)]
+#[non_exhaustive]
+pub enum CatalogResolutionError {
+    #[display("No catalog entry '{alias}' was found for catalog '{catalog_name}'.")]
+    #[diagnostic(code(ERR_PNPM_CATALOG_ENTRY_NOT_FOUND_FOR_SPEC))]
+    EntryNotFoundForSpec { alias: String, catalog_name: String },
+
+    #[display(
+        "Found invalid catalog entry using the catalog protocol recursively. The entry for '{alias}' in catalog '{catalog_name}' is invalid."
+    )]
+    #[diagnostic(code(ERR_PNPM_CATALOG_ENTRY_INVALID_RECURSIVE_DEFINITION))]
+    EntryInvalidRecursiveDefinition { alias: String, catalog_name: String },
+
+    #[display(
+        "The workspace protocol cannot be used as a catalog value. The entry for '{alias}' in catalog '{catalog_name}' is invalid."
+    )]
+    #[diagnostic(code(ERR_PNPM_CATALOG_ENTRY_INVALID_WORKSPACE_SPEC))]
+    EntryInvalidWorkspaceSpec { alias: String, catalog_name: String },
+
+    #[display(
+        "The entry for '{alias}' in catalog '{catalog_name}' declares a dependency using the '{protocol}' protocol. This is not yet supported, but may be in a future version of pnpm."
+    )]
+    #[diagnostic(code(ERR_PNPM_CATALOG_ENTRY_INVALID_SPEC))]
+    EntryInvalidSpec { alias: String, catalog_name: String, protocol: String },
+}
+
+/// Resolve a wanted dependency through the catalogs map.
+///
+/// - Non-`catalog:` specifiers return [`CatalogResolutionResult::Unused`]
+///   so the caller falls through to the next resolver.
+/// - Missing entries, recursive entries, and forbidden protocols
+///   (`workspace:`, `link:`, `file:`) return
+///   [`CatalogResolutionResult::Misconfiguration`].
+/// - A valid entry returns [`CatalogResolutionResult::Found`].
+///
+/// Mirrors upstream's `resolveFromCatalog`
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L60-L130)).
+pub fn resolve_from_catalog(
+    catalogs: &Catalogs,
+    wanted_dependency: &WantedDependency,
+) -> CatalogResolutionResult {
+    let Some(catalog_name) = parse_catalog_protocol(&wanted_dependency.bare_specifier) else {
+        return CatalogResolutionResult::Unused;
+    };
+
+    let catalog_lookup =
+        catalogs.get(catalog_name).and_then(|catalog| catalog.get(&wanted_dependency.alias));
+    let Some(catalog_lookup) = catalog_lookup else {
+        return CatalogResolutionResult::Misconfiguration(CatalogResolutionMisconfiguration {
+            catalog_name: catalog_name.to_string(),
+            error: CatalogResolutionError::EntryNotFoundForSpec {
+                alias: wanted_dependency.alias.clone(),
+                catalog_name: catalog_name.to_string(),
+            },
+        });
+    };
+
+    if parse_catalog_protocol(catalog_lookup).is_some() {
+        return CatalogResolutionResult::Misconfiguration(CatalogResolutionMisconfiguration {
+            catalog_name: catalog_name.to_string(),
+            error: CatalogResolutionError::EntryInvalidRecursiveDefinition {
+                alias: wanted_dependency.alias.clone(),
+                catalog_name: catalog_name.to_string(),
+            },
+        });
+    }
+
+    // Banning `workspace:` matches upstream's three-part justification
+    // ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/src/resolveFromCatalog.ts#L84-L100)):
+    // it's silly to indirect through a catalog when the workspace
+    // protocol resolves directly, and `link:` resolutions cannot be
+    // cached in `pnpm-lock.yaml` across importers the way semver
+    // selectors can.
+    let protocol_of_lookup = catalog_lookup.split(':').next().unwrap_or("");
+    if protocol_of_lookup == "workspace" {
+        return CatalogResolutionResult::Misconfiguration(CatalogResolutionMisconfiguration {
+            catalog_name: catalog_name.to_string(),
+            error: CatalogResolutionError::EntryInvalidWorkspaceSpec {
+                alias: wanted_dependency.alias.clone(),
+                catalog_name: catalog_name.to_string(),
+            },
+        });
+    }
+
+    if matches!(protocol_of_lookup, "link" | "file") {
+        return CatalogResolutionResult::Misconfiguration(CatalogResolutionMisconfiguration {
+            catalog_name: catalog_name.to_string(),
+            error: CatalogResolutionError::EntryInvalidSpec {
+                alias: wanted_dependency.alias.clone(),
+                catalog_name: catalog_name.to_string(),
+                protocol: protocol_of_lookup.to_string(),
+            },
+        });
+    }
+
+    CatalogResolutionResult::Found(CatalogResolutionFound {
+        resolution: CatalogResolution {
+            catalog_name: catalog_name.to_string(),
+            specifier: catalog_lookup.clone(),
+        },
+    })
+}
+
+#[cfg(test)]
+mod tests;
diff --git a/pacquet/crates/catalogs-resolver/src/tests.rs b/pacquet/crates/catalogs-resolver/src/tests.rs
new file mode 100644
index 0000000000..f480f9c681
--- /dev/null
+++ b/pacquet/crates/catalogs-resolver/src/tests.rs
@@ -0,0 +1,187 @@
+//! Ports of `catalogs/resolver/test/resolveFromCatalog.test.ts`
+//! ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/resolver/test/resolveFromCatalog.test.ts)).
+
+use super::{
+    CatalogResolution, CatalogResolutionError, CatalogResolutionFound, CatalogResolutionResult,
+    WantedDependency, resolve_from_catalog,
+};
+use pacquet_catalogs_types::{Catalog, Catalogs};
+
+fn catalogs_from(entries: &[(&str, &[(&str, &str)])]) -> Catalogs {
+    entries
+        .iter()
+        .map(|(name, items)| {
+            let catalog: Catalog =
+                items.iter().map(|(k, v)| ((*k).to_string(), (*v).to_string())).collect();
+            ((*name).to_string(), catalog)
+        })
+        .collect()
+}
+
+fn wanted(alias: &str, bare_specifier: &str) -> WantedDependency {
+    WantedDependency { alias: alias.to_string(), bare_specifier: bare_specifier.to_string() }
+}
+
+#[test]
+fn default_catalog_resolves_using_implicit_name() {
+    let catalogs = catalogs_from(&[("default", &[("foo", "1.0.0")])]);
+    assert_eq!(
+        resolve_from_catalog(&catalogs, &wanted("foo", "catalog:")),
+        CatalogResolutionResult::Found(CatalogResolutionFound {
+            resolution: CatalogResolution {
+                catalog_name: "default".to_string(),
+                specifier: "1.0.0".to_string(),
+            },
+        }),
+    );
+}
+
+#[test]
+fn default_catalog_resolves_using_explicit_name() {
+    let catalogs = catalogs_from(&[("default", &[("foo", "1.0.0")])]);
+    assert_eq!(
+        resolve_from_catalog(&catalogs, &wanted("foo", "catalog:default")),
+        CatalogResolutionResult::Found(CatalogResolutionFound {
+            resolution: CatalogResolution {
+                catalog_name: "default".to_string(),
+                specifier: "1.0.0".to_string(),
+            },
+        }),
+    );
+}
+
+#[test]
+fn resolves_named_catalog() {
+    let catalogs = catalogs_from(&[("foo", &[("bar", "1.0.0")])]);
+    assert_eq!(
+        resolve_from_catalog(&catalogs, &wanted("bar", "catalog:foo")),
+        CatalogResolutionResult::Found(CatalogResolutionFound {
+            resolution: CatalogResolution {
+                catalog_name: "foo".to_string(),
+                specifier: "1.0.0".to_string(),
+            },
+        }),
+    );
+}
+
+#[test]
+fn returns_unused_for_specifier_not_using_catalog_protocol() {
+    let catalogs = catalogs_from(&[("foo", &[("bar", "1.0.0")])]);
+    assert_eq!(
+        resolve_from_catalog(&catalogs, &wanted("bar", "^2.0.0")),
+        CatalogResolutionResult::Unused,
+    );
+}
+
+#[test]
+fn returns_error_for_missing_unresolved_catalog() {
+    let catalogs = catalogs_from(&[("foo", &[("bar", "1.0.0")])]);
+    for (alias, bare, expected_catalog) in [
+        ("bar", "catalog:", "default"),
+        ("bar", "catalog:baz", "baz"),
+        ("foo", "catalog:foo", "foo"),
+    ] {
+        let result = resolve_from_catalog(&catalogs, &wanted(alias, bare));
+        let CatalogResolutionResult::Misconfiguration(misconfig) = &result else {
+            panic!("expected misconfiguration for ({alias}, {bare}), got {result:?}");
+        };
+        assert_eq!(misconfig.catalog_name, expected_catalog);
+        assert_eq!(
+            misconfig.error,
+            CatalogResolutionError::EntryNotFoundForSpec {
+                alias: alias.to_string(),
+                catalog_name: expected_catalog.to_string(),
+            },
+        );
+        assert_eq!(
+            misconfig.error.to_string(),
+            format!("No catalog entry '{alias}' was found for catalog '{expected_catalog}'."),
+        );
+    }
+}
+
+#[test]
+fn returns_error_for_recursive_catalog() {
+    let catalogs = catalogs_from(&[("foo", &[("bar", "catalog:foo")])]);
+    let result = resolve_from_catalog(&catalogs, &wanted("bar", "catalog:foo"));
+    let CatalogResolutionResult::Misconfiguration(misconfig) = &result else {
+        panic!("expected misconfiguration, got {result:?}");
+    };
+    assert_eq!(
+        misconfig.error,
+        CatalogResolutionError::EntryInvalidRecursiveDefinition {
+            alias: "bar".to_string(),
+            catalog_name: "foo".to_string(),
+        },
+    );
+    assert_eq!(
+        misconfig.error.to_string(),
+        "Found invalid catalog entry using the catalog protocol recursively. \
+         The entry for 'bar' in catalog 'foo' is invalid.",
+    );
+}
+
+#[test]
+fn returns_error_for_workspace_protocol_in_catalog() {
+    let catalogs = catalogs_from(&[("foo", &[("bar", "workspace:*")])]);
+    let result = resolve_from_catalog(&catalogs, &wanted("bar", "catalog:foo"));
+    let CatalogResolutionResult::Misconfiguration(misconfig) = &result else {
+        panic!("expected misconfiguration, got {result:?}");
+    };
+    assert_eq!(
+        misconfig.error,
+        CatalogResolutionError::EntryInvalidWorkspaceSpec {
+            alias: "bar".to_string(),
+            catalog_name: "foo".to_string(),
+        },
+    );
+    assert_eq!(
+        misconfig.error.to_string(),
+        "The workspace protocol cannot be used as a catalog value. \
+         The entry for 'bar' in catalog 'foo' is invalid.",
+    );
+}
+
+#[test]
+fn returns_error_for_file_protocol_in_catalog() {
+    let catalogs = catalogs_from(&[("foo", &[("bar", "file:./bar.tgz")])]);
+    let result = resolve_from_catalog(&catalogs, &wanted("bar", "catalog:foo"));
+    let CatalogResolutionResult::Misconfiguration(misconfig) = &result else {
+        panic!("expected misconfiguration, got {result:?}");
+    };
+    assert_eq!(
+        misconfig.error,
+        CatalogResolutionError::EntryInvalidSpec {
+            alias: "bar".to_string(),
+            catalog_name: "foo".to_string(),
+            protocol: "file".to_string(),
+        },
+    );
+    assert_eq!(
+        misconfig.error.to_string(),
+        "The entry for 'bar' in catalog 'foo' declares a dependency using the 'file' protocol. \
+         This is not yet supported, but may be in a future version of pnpm.",
+    );
+}
+
+#[test]
+fn returns_error_for_link_protocol_in_catalog() {
+    let catalogs = catalogs_from(&[("foo", &[("bar", "link:./bar")])]);
+    let result = resolve_from_catalog(&catalogs, &wanted("bar", "catalog:foo"));
+    let CatalogResolutionResult::Misconfiguration(misconfig) = &result else {
+        panic!("expected misconfiguration, got {result:?}");
+    };
+    assert_eq!(
+        misconfig.error,
+        CatalogResolutionError::EntryInvalidSpec {
+            alias: "bar".to_string(),
+            catalog_name: "foo".to_string(),
+            protocol: "link".to_string(),
+        },
+    );
+    assert_eq!(
+        misconfig.error.to_string(),
+        "The entry for 'bar' in catalog 'foo' declares a dependency using the 'link' protocol. \
+         This is not yet supported, but may be in a future version of pnpm.",
+    );
+}
diff --git a/pacquet/crates/catalogs-types/Cargo.toml b/pacquet/crates/catalogs-types/Cargo.toml
new file mode 100644
index 0000000000..e15f1a229f
--- /dev/null
+++ b/pacquet/crates/catalogs-types/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name                  = "pacquet-catalogs-types"
+version               = "0.0.1"
+publish               = false
+authors.workspace     = true
+description.workspace = true
+edition.workspace     = true
+homepage.workspace    = true
+keywords.workspace    = true
+license.workspace     = true
+repository.workspace  = true
+
+[dependencies]
+
+[lints]
+workspace = true
diff --git a/pacquet/crates/catalogs-types/src/lib.rs b/pacquet/crates/catalogs-types/src/lib.rs
new file mode 100644
index 0000000000..95216d7772
--- /dev/null
+++ b/pacquet/crates/catalogs-types/src/lib.rs
@@ -0,0 +1,30 @@
+//! Pacquet port of pnpm's
+//! [`@pnpm/catalogs.types`](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/types/src/index.ts).
+//!
+//! Defines [`Catalog`] and [`Catalogs`], the normalized in-memory shape
+//! every other catalogs crate consumes. Both are plain typed maps in
+//! upstream — `interface Catalog { [name: string]: string | undefined }`
+//! and `interface Catalogs { default?: Catalog; [name: string]: Catalog
+//! | undefined }` — so pacquet exposes them as `BTreeMap` aliases. The
+//! `"default"` catalog is just the well-known key inside [`Catalogs`];
+//! no separate field is needed.
+
+use std::collections::BTreeMap;
+
+/// The well-known name of the default catalog. Matches the literal pnpm
+/// uses everywhere a catalog name is implicit.
+pub const DEFAULT_CATALOG_NAME: &str = "default";
+
+/// One catalog: a map of dependency name to version specifier.
+///
+/// Mirrors upstream's `Catalog` interface
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/types/src/index.ts#L27-L29)).
+pub type Catalog = BTreeMap<String, String>;
+
+/// The full set of catalogs parsed from `pnpm-workspace.yaml`. The
+/// default catalog lives at the [`DEFAULT_CATALOG_NAME`] key; any other
+/// key is a user-defined named catalog.
+///
+/// Mirrors upstream's `Catalogs` interface
+/// ([source](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/types/src/index.ts#L1-L25)).
+pub type Catalogs = BTreeMap<String, Catalog>;
diff --git a/pacquet/crates/cli/tests/install.rs b/pacquet/crates/cli/tests/install.rs
index 1d77c457fd..39680bfeec 100644
--- a/pacquet/crates/cli/tests/install.rs
+++ b/pacquet/crates/cli/tests/install.rs
@@ -364,3 +364,84 @@ fn auto_install_peers_hoists_missing_peers_at_importer() {
 
     drop((root, mock_instance)); // cleanup
 }
+
+/// `catalog:` on a direct dep should be dereferenced through
+/// `pnpm-workspace.yaml`'s `catalog` section before the npm resolver
+/// sees it. The fetched virtual-store entry is the catalog's resolved
+/// version, not the literal `catalog:` string.
+///
+/// Mirrors the upstream end-to-end coverage in
+/// [`installing/deps-installer/test/catalogs.ts`](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/installing/deps-installer/test/catalogs.ts).
+#[test]
+fn install_resolves_catalog_protocol() {
+    let CommandTempCwd { pacquet, root, workspace, npmrc_info, .. } =
+        CommandTempCwd::init().add_mocked_registry();
+    let AddMockedRegistry { mock_instance, .. } = npmrc_info;
+
+    eprintln!("Appending catalog to pnpm-workspace.yaml...");
+    let workspace_yaml = workspace.join("pnpm-workspace.yaml");
+    let mut existing = fs::read_to_string(&workspace_yaml).expect("read pnpm-workspace.yaml");
+    existing.push_str("catalog:\n  '@pnpm.e2e/hello-world-js-bin-parent': '1.0.0'\n");
+    fs::write(&workspace_yaml, existing).expect("write pnpm-workspace.yaml");
+
+    eprintln!("Creating package.json that uses the catalog protocol...");
+    let manifest_path = workspace.join("package.json");
+    let package_json_content = serde_json::json!({
+        "dependencies": {
+            "@pnpm.e2e/hello-world-js-bin-parent": "catalog:",
+        },
+    });
+    fs::write(&manifest_path, package_json_content.to_string()).expect("write to package.json");
+
+    eprintln!("Executing command...");
+    pacquet.with_arg("install").assert().success();
+
+    eprintln!("Make sure the package is installed at the catalog's version");
+    let symlink_path = workspace.join("node_modules/@pnpm.e2e/hello-world-js-bin-parent");
+    assert!(is_symlink_or_junction(&symlink_path).unwrap());
+    let virtual_path =
+        workspace.join("node_modules/.pnpm/@pnpm.e2e+hello-world-js-bin-parent@1.0.0");
+    assert!(virtual_path.exists(), "expected virtual store entry at {virtual_path:?}");
+
+    drop((root, mock_instance)); // cleanup
+}
+
+/// A misconfigured catalog (specifier points at a missing entry) must
+/// fail the install with the upstream `ERR_PNPM_CATALOG_ENTRY_NOT_FOUND_FOR_SPEC`
+/// rather than the chain's `SPEC_NOT_SUPPORTED_BY_ANY_RESOLVER`.
+#[test]
+fn install_surfaces_catalog_misconfiguration() {
+    let CommandTempCwd { pacquet, root, workspace, npmrc_info, .. } =
+        CommandTempCwd::init().add_mocked_registry();
+    let AddMockedRegistry { mock_instance, .. } = npmrc_info;
+
+    eprintln!("Creating package.json with a catalog: dep but no matching catalog entry...");
+    let manifest_path = workspace.join("package.json");
+    let package_json_content = serde_json::json!({
+        "dependencies": {
+            "@pnpm.e2e/hello-world-js-bin-parent": "catalog:",
+        },
+    });
+    fs::write(&manifest_path, package_json_content.to_string()).expect("write to package.json");
+
+    eprintln!("Executing command...");
+    let output = pacquet.with_arg("install").assert().failure();
+    let stderr = String::from_utf8_lossy(&output.get_output().stderr);
+    eprintln!("stderr={stderr}");
+    // The miette report hard-wraps the message and inserts a leading
+    // `│` on the wrapped line. Strip all whitespace and box-drawing
+    // characters before substring-matching so wrap position can't
+    // make the assertion brittle.
+    let flattened: String = stderr
+        .chars()
+        .filter(|ch| !ch.is_whitespace() && !matches!(ch, '│' | '├' | '╰' | '─' | '▶' | '×'))
+        .collect();
+    assert!(
+        flattened.contains(
+            "Nocatalogentry'@pnpm.e2e/hello-world-js-bin-parent'wasfoundforcatalog'default'.",
+        ),
+        "stderr did not mention the missing-catalog-entry error: {stderr}",
+    );
+
+    drop((root, mock_instance)); // cleanup
+}
diff --git a/pacquet/crates/package-manager/Cargo.toml b/pacquet/crates/package-manager/Cargo.toml
index 3cdf883a43..5d33982af4 100644
--- a/pacquet/crates/package-manager/Cargo.toml
+++ b/pacquet/crates/package-manager/Cargo.toml
@@ -11,6 +11,8 @@ license.workspace     = true
 repository.workspace  = true
 
 [dependencies]
+pacquet-catalogs-config              = { workspace = true }
+pacquet-catalogs-types               = { workspace = true }
 pacquet-cmd-shim                     = { workspace = true }
 pacquet-crypto-hash                  = { workspace = true }
 pacquet-deps-path                    = { workspace = true }
diff --git a/pacquet/crates/package-manager/src/install.rs b/pacquet/crates/package-manager/src/install.rs
index 12e93da206..2a24529b1a 100644
--- a/pacquet/crates/package-manager/src/install.rs
+++ b/pacquet/crates/package-manager/src/install.rs
@@ -7,6 +7,9 @@ use crate::{
 };
 use derive_more::{Display, Error};
 use miette::Diagnostic;
+use pacquet_catalogs_config::{
+    InvalidCatalogsConfigurationError, get_catalogs_from_workspace_manifest,
+};
 use pacquet_config::{Config, NodeLinker};
 use pacquet_lockfile::{
     LoadLockfileError, Lockfile, SaveLockfileError, StalenessReason, satisfies_package_manifest,
@@ -166,6 +169,17 @@ pub enum InstallError {
     #[diagnostic(transparent)]
     FindWorkspaceDir(#[error(source)] pacquet_workspace::FindWorkspaceDirError),
 
+    /// Reading `pnpm-workspace.yaml` to extract its `catalog` /
+    /// `catalogs` sections failed.
+    #[diagnostic(transparent)]
+    ReadWorkspaceManifest(#[error(source)] pacquet_workspace::ReadWorkspaceManifestError),
+
+    /// `pnpm-workspace.yaml` defined the `default` catalog twice
+    /// (once via the top-level `catalog:` field and once via
+    /// `catalogs.default`).
+    #[diagnostic(transparent)]
+    InvalidCatalogsConfiguration(#[error(source)] InvalidCatalogsConfigurationError),
+
     /// Building the verifier list from config rejected a
     /// `minimumReleaseAgeExclude` or `trustPolicyExclude` pattern.
     /// Mirrors upstream's `INVALID_MINIMUM_RELEASE_AGE_EXCLUDE` /
@@ -239,9 +253,24 @@ where
         //
         // [bunyan]: https://github.com/trentm/node-bunyan
         let manifest_dir = manifest.path().parent().expect("manifest path always has a parent dir");
-        let workspace_root = pacquet_workspace::find_workspace_dir(manifest_dir)
-            .map_err(InstallError::FindWorkspaceDir)?
-            .unwrap_or_else(|| manifest_dir.to_path_buf());
+        let workspace_dir_opt = pacquet_workspace::find_workspace_dir(manifest_dir)
+            .map_err(InstallError::FindWorkspaceDir)?;
+        let workspace_root =
+            workspace_dir_opt.clone().unwrap_or_else(|| manifest_dir.to_path_buf());
+
+        // Read `pnpm-workspace.yaml` for the catalog sections. Only
+        // consulted when a workspace manifest exists — single-project
+        // installs have no `catalog:` to honor. Mirrors upstream's
+        // `getCatalogsFromWorkspaceManifest(readWorkspaceManifest(...))`
+        // pipeline at
+        // <https://github.com/pnpm/pnpm/blob/a8a8cbce6d/catalogs/config/src/getCatalogsFromWorkspaceManifest.ts>.
+        let workspace_manifest = match workspace_dir_opt.as_deref() {
+            Some(dir) => pacquet_workspace::read_workspace_manifest(dir)
+                .map_err(InstallError::ReadWorkspaceManifest)?,
+            None => None,
+        };
+        let catalogs = get_catalogs_from_workspace_manifest(workspace_manifest.as_ref())
+            .map_err(InstallError::InvalidCatalogsConfiguration)?;
         // Use `to_string_lossy` rather than `to_str().expect(...)` so a
         // valid filesystem path with non-UTF-8 bytes (possible on Unix)
         // doesn't panic the installer. `prefix` is used only for
@@ -519,6 +548,7 @@ where
                 dependency_groups,
                 logged_methods: &logged_methods,
                 requester: &prefix,
+                catalogs,
             }
             .run::<Reporter>()
             .await
diff --git a/pacquet/crates/package-manager/src/install_without_lockfile.rs b/pacquet/crates/package-manager/src/install_without_lockfile.rs
index 4cc69eb782..412609ae86 100644
--- a/pacquet/crates/package-manager/src/install_without_lockfile.rs
+++ b/pacquet/crates/package-manager/src/install_without_lockfile.rs
@@ -7,6 +7,7 @@ use dashmap::{DashMap, mapref::entry::Entry};
 use derive_more::{Display, Error};
 use futures_util::future;
 use miette::Diagnostic;
+use pacquet_catalogs_types::Catalogs;
 use pacquet_cmd_shim::{Host, LinkBinsError, link_bins};
 use pacquet_config::Config;
 use pacquet_engine_runtime_bun_resolver::BunResolver;
@@ -85,6 +86,9 @@ pub struct InstallWithoutLockfile<'a, DependencyGroupList> {
     pub logged_methods: &'a AtomicU8,
     /// Install root, threaded into reporter `requester` fields.
     pub requester: &'a str,
+    /// Catalogs parsed from `pnpm-workspace.yaml`. Empty for projects
+    /// without a workspace manifest.
+    pub catalogs: Catalogs,
 }
 
 /// Error type of [`InstallWithoutLockfile`].
@@ -170,6 +174,7 @@ impl<'a, DependencyGroupList> InstallWithoutLockfile<'a, DependencyGroupList> {
             resolved_packages,
             logged_methods,
             requester,
+            catalogs,
         } = self;
 
         let store_dir: &'static _ = &config.store_dir;
@@ -314,6 +319,7 @@ impl<'a, DependencyGroupList> InstallWithoutLockfile<'a, DependencyGroupList> {
                 published_by_exclude,
                 ..ResolveOptions::default()
             },
+            catalogs,
         };
 
         let importer_result =
diff --git a/pacquet/crates/resolving-deps-resolver/Cargo.toml b/pacquet/crates/resolving-deps-resolver/Cargo.toml
index dfbd140f43..2a5362a013 100644
--- a/pacquet/crates/resolving-deps-resolver/Cargo.toml
+++ b/pacquet/crates/resolving-deps-resolver/Cargo.toml
@@ -11,6 +11,8 @@ license.workspace     = true
 repository.workspace  = true
 
 [dependencies]
+pacquet-catalogs-resolver       = { workspace = true }
+pacquet-catalogs-types          = { workspace = true }
 pacquet-deps-path               = { workspace = true }
 pacquet-package-manifest        = { workspace = true }
 pacquet-resolving-resolver-base = { workspace = true }
diff --git a/pacquet/crates/resolving-deps-resolver/src/resolve_dependency_tree.rs b/pacquet/crates/resolving-deps-resolver/src/resolve_dependency_tree.rs
index ee74ffd32a..8b8a2b4d58 100644
--- a/pacquet/crates/resolving-deps-resolver/src/resolve_dependency_tree.rs
+++ b/pacquet/crates/resolving-deps-resolver/src/resolve_dependency_tree.rs
@@ -4,6 +4,11 @@ use async_recursion::async_recursion;
 use derive_more::{Display, Error};
 use futures_util::future;
 use miette::Diagnostic;
+use pacquet_catalogs_resolver::{
+    CatalogResolutionError, CatalogResolutionResult, WantedDependency as CatalogWantedDependency,
+    resolve_from_catalog,
+};
+use pacquet_catalogs_types::Catalogs;
 use pacquet_package_manifest::{DependencyGroup, PackageManifest};
 use pacquet_resolving_resolver_base::{ResolveError, ResolveOptions, Resolver, WantedDependency};
 use pipe_trait::Pipe;
@@ -48,6 +53,13 @@ pub enum ResolveDependencyTreeError {
         #[error(not(source))]
         specifier: String,
     },
+
+    /// A `catalog:` specifier on a direct dependency referenced a
+    /// missing entry, used a forbidden protocol, or was otherwise
+    /// misconfigured. The inner error carries the upstream
+    /// `ERR_PNPM_CATALOG_ENTRY_*` code and message.
+    #[diagnostic(transparent)]
+    CatalogMisconfiguration(#[error(source)] CatalogResolutionError),
 }
 
 /// Walk `manifest` plus the entries in `dependency_groups`, dispatch
@@ -306,6 +318,35 @@ where
     Ok(Some(DirectDep { alias, node_id, id }))
 }
 
+/// Replace `catalog:` bare specifiers on direct dependencies with the
+/// version recorded in the catalogs map. Non-`catalog:` specifiers
+/// pass through unchanged.
+///
+/// Catalog resolution runs only on importer-level deps, matching
+/// upstream's
+/// [importer-only scope](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/installing/deps-resolver/src/resolveDependencies.ts#L592-L600).
+/// A misconfigured entry surfaces immediately rather than masquerading
+/// as a `SPEC_NOT_SUPPORTED_BY_ANY_RESOLVER`.
+pub(crate) fn resolve_catalog_specifiers(
+    specs: Vec<(String, String)>,
+    catalogs: &Catalogs,
+) -> Result<Vec<(String, String)>, ResolveDependencyTreeError> {
+    specs
+        .into_iter()
+        .map(|(name, range)| {
+            let wanted =
+                CatalogWantedDependency { alias: name.clone(), bare_specifier: range.clone() };
+            match resolve_from_catalog(catalogs, &wanted) {
+                CatalogResolutionResult::Found(found) => Ok((name, found.resolution.specifier)),
+                CatalogResolutionResult::Unused => Ok((name, range)),
+                CatalogResolutionResult::Misconfiguration(misconfig) => {
+                    Err(ResolveDependencyTreeError::CatalogMisconfiguration(misconfig.error))
+                }
+            }
+        })
+        .collect()
+}
+
 /// Render `{alias}@{bare}` (either half dropped when absent) for the
 /// error message. Mirrors upstream's `render_specifier` shape in
 /// `default-resolver`.
diff --git a/pacquet/crates/resolving-deps-resolver/src/resolve_importer.rs b/pacquet/crates/resolving-deps-resolver/src/resolve_importer.rs
index 5f5dc016eb..80963c5b61 100644
--- a/pacquet/crates/resolving-deps-resolver/src/resolve_importer.rs
+++ b/pacquet/crates/resolving-deps-resolver/src/resolve_importer.rs
@@ -24,6 +24,7 @@ use std::collections::{BTreeMap, BTreeSet, HashSet};
 
 use derive_more::{Display, Error};
 use miette::Diagnostic;
+use pacquet_catalogs_types::Catalogs;
 use pacquet_package_manifest::{DependencyGroup, PackageManifest};
 use pacquet_resolving_resolver_base::{
     PreferredVersions, ResolveOptions, Resolver, VersionSelectorEntry, VersionSelectorType,
@@ -36,7 +37,9 @@ use crate::{
         HoistPeersOptions, MissingPeerInfo, WorkspaceRootDep, get_hoistable_optional_peers,
         hoist_peers,
     },
-    resolve_dependency_tree::{ResolveDependencyTreeError, TreeCtx, extend_tree},
+    resolve_dependency_tree::{
+        ResolveDependencyTreeError, TreeCtx, extend_tree, resolve_catalog_specifiers,
+    },
     resolve_peers::{ResolvePeersOptions, ResolvePeersResult, resolve_peers},
     resolved_tree::ResolvedTree,
 };
@@ -72,6 +75,12 @@ pub struct ResolveImporterOptions {
     pub all_preferred_versions: PreferredVersions,
 
     pub base_opts: ResolveOptions,
+
+    /// Catalogs parsed from `pnpm-workspace.yaml`. Applied only to the
+    /// importer's direct dependencies; transitive `catalog:` entries
+    /// are not resolved through the catalog, matching upstream's
+    /// [importer-only catalog scope](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/installing/deps-resolver/src/resolveDependencies.ts#L592-L600).
+    pub catalogs: Catalogs,
 }
 
 /// Result of [`fn@resolve_importer`] — the fully-walked tree plus the
@@ -113,6 +122,7 @@ where
         resolve_peers_from_workspace_root,
         mut all_preferred_versions,
         base_opts,
+        catalogs,
     } = opts;
 
     let ctx = TreeCtx::new(base_opts);
@@ -131,6 +141,7 @@ where
         .dependencies(groups)
         .map(|(name, range)| (name.to_string(), range.to_string()))
         .collect();
+    let initial_wanted = resolve_catalog_specifiers(initial_wanted, &catalogs)?;
     let mut direct = extend_tree(&ctx, resolver, initial_wanted).await?;
     update_preferred_versions_with_ctx(&ctx, &mut all_preferred_versions).await;
 
diff --git a/pacquet/crates/resolving-deps-resolver/src/resolve_importer/tests.rs b/pacquet/crates/resolving-deps-resolver/src/resolve_importer/tests.rs
index 38c2a72bcb..7178750b6a 100644
--- a/pacquet/crates/resolving-deps-resolver/src/resolve_importer/tests.rs
+++ b/pacquet/crates/resolving-deps-resolver/src/resolve_importer/tests.rs
@@ -7,7 +7,10 @@ use pacquet_resolving_resolver_base::{
 };
 use pretty_assertions::assert_eq;
 
-use crate::{DepPath, resolve_importer, resolve_importer::ResolveImporterOptions};
+use crate::{
+    DepPath, ResolveDependencyTreeError, resolve_importer,
+    resolve_importer::{ResolveImporterError, ResolveImporterOptions},
+};
 
 struct StubResolver {
     table: HashMap<(String, String), ResolveResult>,
@@ -86,6 +89,7 @@ fn default_opts() -> ResolveImporterOptions {
         resolve_peers_from_workspace_root: false,
         all_preferred_versions: PreferredVersions::new(),
         base_opts: ResolveOptions::default(),
+        catalogs: pacquet_catalogs_types::Catalogs::new(),
     }
 }
 
@@ -766,3 +770,57 @@ async fn auto_install_hoisted_peer_dep_reuses_regular_dep_version() {
         "expected one c@2.0.0 entry (not a second copy via the peer arm), got: {c_entries:?}",
     );
 }
+
+/// `catalog:` on a direct dependency is rewritten to the catalog's
+/// recorded specifier before the resolver chain sees the wanted dep.
+/// Mirrors upstream's
+/// [importer-only catalog dereference](https://github.com/pnpm/pnpm/blob/a8a8cbce6d/installing/deps-resolver/src/resolveDependencies.ts#L592-L611).
+#[tokio::test]
+async fn catalog_protocol_on_direct_dep_is_rewritten() {
+    let mut table = HashMap::new();
+    table.insert(
+        ("foo".to_string(), "^1.0.0".to_string()),
+        fake_result("foo", "1.2.0", serde_json::json!({ "name": "foo", "version": "1.2.0" })),
+    );
+    let resolver = StubResolver { table, calls: Mutex::new(Vec::new()) };
+    let (_tmp, manifest) = fake_manifest(serde_json::json!({ "foo": "catalog:" }));
+
+    let mut catalogs = pacquet_catalogs_types::Catalogs::new();
+    catalogs.insert(
+        "default".to_string(),
+        [("foo".to_string(), "^1.0.0".to_string())].into_iter().collect(),
+    );
+
+    let opts = ResolveImporterOptions { catalogs, ..default_opts() };
+    let result =
+        resolve_importer(&resolver, &manifest, [DependencyGroup::Prod], opts).await.unwrap();
+    assert_eq!(result.resolved_tree.direct.len(), 1);
+    assert_eq!(result.resolved_tree.direct[0].alias, "foo");
+    // The resolver chain only sees the catalog-rewritten range.
+    let calls = resolver.calls.lock().unwrap();
+    assert_eq!(&*calls, &[("foo".to_string(), "^1.0.0".to_string())]);
+}
+
+/// A misconfigured `catalog:` entry (here: missing alias) short-
+/// circuits resolution with the upstream `CATALOG_ENTRY_NOT_FOUND_FOR_SPEC`
+/// error rather than falling through to `SpecNotSupported`.
+#[tokio::test]
+async fn catalog_misconfiguration_surfaces_pnpm_error_code() {
+    let resolver = StubResolver { table: HashMap::new(), calls: Mutex::new(Vec::new()) };
+    let (_tmp, manifest) = fake_manifest(serde_json::json!({ "foo": "catalog:" }));
+
+    let err = resolve_importer(&resolver, &manifest, [DependencyGroup::Prod], default_opts())
+        .await
+        .expect_err("missing catalog entry must error");
+    match err {
+        ResolveImporterError::Resolve(ResolveDependencyTreeError::CatalogMisconfiguration(
+            inner,
+        )) => {
+            assert_eq!(
+                inner.to_string(),
+                "No catalog entry 'foo' was found for catalog 'default'.",
+            );
+        }
+        other => panic!("expected CatalogMisconfiguration, got {other:?}"),
+    }
+}
diff --git a/pacquet/crates/workspace/Cargo.toml b/pacquet/crates/workspace/Cargo.toml
index ff5aab8461..7f93efef4a 100644
--- a/pacquet/crates/workspace/Cargo.toml
+++ b/pacquet/crates/workspace/Cargo.toml
@@ -11,6 +11,7 @@ license.workspace     = true
 repository.workspace  = true
 
 [dependencies]
+pacquet-catalogs-types   = { workspace = true }
 pacquet-package-manifest = { workspace = true }
 
 derive_more  = { workspace = true }
diff --git a/pacquet/crates/workspace/src/manifest.rs b/pacquet/crates/workspace/src/manifest.rs
index c86fc29fd2..51a258d5a6 100644
--- a/pacquet/crates/workspace/src/manifest.rs
+++ b/pacquet/crates/workspace/src/manifest.rs
@@ -23,6 +23,7 @@
 
 use derive_more::{Display, Error};
 use miette::Diagnostic;
+use pacquet_catalogs_types::{Catalog, Catalogs};
 use serde::Deserialize;
 use std::{
     fs,
@@ -41,11 +42,6 @@ pub const WORKSPACE_MANIFEST_FILENAME: &str = "pnpm-workspace.yaml";
 /// Splitting along the upstream package boundary keeps each reader
 /// focused on the shape its callers actually need and avoids a
 /// monolithic struct that has to grow with every new pnpm setting.
-///
-/// Catalogs are accepted at parse time but not yet consumed downstream
-/// — they belong to Stage 2 of the workspace roadmap. Parsing them now
-/// keeps `pnpm-workspace.yaml` files with catalog entries valid input
-/// to pacquet rather than tripping `deny_unknown_fields`.
 #[derive(Debug, Default, PartialEq, Deserialize)]
 #[serde(rename_all = "camelCase")]
 pub struct WorkspaceManifest {
@@ -61,6 +57,17 @@ pub struct WorkspaceManifest {
     /// promote `packages: []` into a recursive scan.
     #[serde(default)]
     pub packages: Option<Vec<String>>,
+
+    /// Top-level shorthand for the default catalog. Mutually exclusive
+    /// with `catalogs.default` — `pacquet_catalogs_config` enforces
+    /// that.
+    #[serde(default)]
+    pub catalog: Option<Catalog>,
+
+    /// Named catalogs. Includes a `default` key when the user opted for
+    /// the explicit form over the top-level [`Self::catalog`] field.
+    #[serde(default)]
+    pub catalogs: Option<Catalogs>,
 }
 
 /// Raised when `pnpm-workspace.yaml` parses as YAML but fails an
diff --git a/pacquet/crates/workspace/src/manifest/tests.rs b/pacquet/crates/workspace/src/manifest/tests.rs
index b31bab5ba9..5729e9d516 100644
--- a/pacquet/crates/workspace/src/manifest/tests.rs
+++ b/pacquet/crates/workspace/src/manifest/tests.rs
@@ -2,6 +2,7 @@ use super::{
     InvalidWorkspaceManifestError, ReadWorkspaceManifestError, WORKSPACE_MANIFEST_FILENAME,
     WorkspaceManifest, read_workspace_manifest,
 };
+use pacquet_catalogs_types::{Catalog, Catalogs};
 use pretty_assertions::assert_eq;
 use std::fs;
 use tempfile::TempDir;
@@ -65,6 +66,40 @@ fn empty_packages_array_preserved_as_some_empty() {
     assert_eq!(manifest.packages, Some(Vec::<String>::new()));
 }
 
+#[test]
+fn parses_top_level_catalog_field() {
+    let tmp = TempDir::new().unwrap();
+    fs::write(
+        tmp.path().join(WORKSPACE_MANIFEST_FILENAME),
+        "catalog:\n  foo: ^1.0.0\n  bar: ^2.0.0\n",
+    )
+    .unwrap();
+    let manifest = read_workspace_manifest(tmp.path()).unwrap().unwrap();
+    let mut expected = Catalog::new();
+    expected.insert("foo".to_string(), "^1.0.0".to_string());
+    expected.insert("bar".to_string(), "^2.0.0".to_string());
+    assert_eq!(manifest.catalog, Some(expected));
+    assert_eq!(manifest.catalogs, None);
+}
+
+#[test]
+fn parses_named_catalogs_field() {
+    let tmp = TempDir::new().unwrap();
+    fs::write(
+        tmp.path().join(WORKSPACE_MANIFEST_FILENAME),
+        "catalogs:\n  default:\n    foo: ^1.0.0\n  legacy:\n    bar: ^2.0.0\n",
+    )
+    .unwrap();
+    let manifest = read_workspace_manifest(tmp.path()).unwrap().unwrap();
+    let mut expected = Catalogs::new();
+    expected
+        .insert("default".to_string(), Catalog::from([("foo".to_string(), "^1.0.0".to_string())]));
+    expected
+        .insert("legacy".to_string(), Catalog::from([("bar".to_string(), "^2.0.0".to_string())]));
+    assert_eq!(manifest.catalog, None);
+    assert_eq!(manifest.catalogs, Some(expected));
+}
+
 #[test]
 fn empty_package_entry_rejected() {
     let tmp = TempDir::new().unwrap();