diff --git a/daemon.go b/daemon.go
index ffa71bf..f0565ac 100644
--- a/daemon.go
+++ b/daemon.go
@@ -3,10 +3,11 @@ package process
 import (
 	"context"
 	"errors"
-	"fmt"
 	"os"
 	"sync"
 	"time"
+
+	coreerr "forge.lthn.ai/core/go-log"
 )
 
 // DaemonOptions configures daemon mode execution.
@@ -72,7 +73,7 @@ func (d *Daemon) Start() error {
 	defer d.mu.Unlock()
 
 	if d.running {
-		return errors.New("daemon already running")
+		return coreerr.E("Daemon.Start", "daemon already running", nil)
 	}
 
 	if d.pid != nil {
@@ -100,7 +101,7 @@ func (d *Daemon) Start() error {
 			entry.Health = d.health.Addr()
 		}
 		if err := d.opts.Registry.Register(entry); err != nil {
-			return fmt.Errorf("registry: %w", err)
+			return coreerr.E("Daemon.Start", "registry", err)
 		}
 	}
 
@@ -112,7 +113,7 @@ func (d *Daemon) Run(ctx context.Context) error {
 	d.mu.Lock()
 	if !d.running {
 		d.mu.Unlock()
-		return errors.New("daemon not started - call Start() first")
+		return coreerr.E("Daemon.Run", "daemon not started - call Start() first", nil)
 	}
 	d.mu.Unlock()
 
@@ -138,13 +139,13 @@ func (d *Daemon) Stop() error {
 	if d.health != nil {
 		d.health.SetReady(false)
 		if err := d.health.Stop(shutdownCtx); err != nil {
-			errs = append(errs, fmt.Errorf("health server: %w", err))
+			errs = append(errs, coreerr.E("Daemon.Stop", "health server", err))
 		}
 	}
 
 	if d.pid != nil {
 		if err := d.pid.Release(); err != nil && !os.IsNotExist(err) {
-			errs = append(errs, fmt.Errorf("pid file: %w", err))
+			errs = append(errs, coreerr.E("Daemon.Stop", "pid file", err))
 		}
 	}
 
diff --git a/exec/exec.go b/exec/exec.go
index 21978a9..ae875a0 100644
--- a/exec/exec.go
+++ b/exec/exec.go
@@ -8,6 +8,8 @@ import (
 	"os"
 	"os/exec"
 	"strings"
+
+	coreerr "forge.lthn.ai/core/go-log"
 )
 
 // Options configuration for command execution
@@ -147,7 +149,7 @@ func RunQuiet(ctx context.Context, name string, args ...string) error {
 	cmd := Command(ctx, name, args...).WithStderr(&stderr)
 	if err := cmd.Run(); err != nil {
 		// Include stderr in error message
-		return fmt.Errorf("%w: %s", err, strings.TrimSpace(stderr.String()))
+		return coreerr.E("RunQuiet", strings.TrimSpace(stderr.String()), err)
 	}
 	return nil
 }
@@ -155,9 +157,9 @@ func RunQuiet(ctx context.Context, name string, args ...string) error {
 func wrapError(err error, name string, args []string) error {
 	cmdStr := name + " " + strings.Join(args, " ")
 	if exitErr, ok := err.(*exec.ExitError); ok {
-		return fmt.Errorf("command %q failed with exit code %d: %w", cmdStr, exitErr.ExitCode(), err)
+		return coreerr.E("wrapError", fmt.Sprintf("command %q failed with exit code %d", cmdStr, exitErr.ExitCode()), err)
 	}
-	return fmt.Errorf("failed to execute %q: %w", cmdStr, err)
+	return coreerr.E("wrapError", fmt.Sprintf("failed to execute %q", cmdStr), err)
 }
 
 func (c *Cmd) getLogger() Logger {
diff --git a/go.mod b/go.mod
index 3a0b343..4e5072c 100644
--- a/go.mod
+++ b/go.mod
@@ -6,13 +6,13 @@ require (
 	forge.lthn.ai/core/api v0.1.2
 	forge.lthn.ai/core/go v0.3.1
 	forge.lthn.ai/core/go-io v0.1.2
+	forge.lthn.ai/core/go-log v0.0.2
 	forge.lthn.ai/core/go-ws v0.2.0
 	github.com/gin-gonic/gin v1.12.0
 	github.com/stretchr/testify v1.11.1
 )
 
 require (
-	forge.lthn.ai/core/go-log v0.0.2 // indirect
 	github.com/99designs/gqlgen v0.17.88 // indirect
 	github.com/KyleBanks/depth v1.2.1 // indirect
 	github.com/agnivade/levenshtein v1.2.1 // indirect
diff --git a/health.go b/health.go
index 0f8563a..98ecdd3 100644
--- a/health.go
+++ b/health.go
@@ -7,6 +7,8 @@ import (
 	"net/http"
 	"sync"
 	"time"
+
+	coreerr "forge.lthn.ai/core/go-log"
 )
 
 // HealthCheck is a function that returns nil if healthy.
@@ -82,7 +84,7 @@ func (h *HealthServer) Start() error {
 
 	listener, err := net.Listen("tcp", h.addr)
 	if err != nil {
-		return fmt.Errorf("failed to listen on %s: %w", h.addr, err)
+		return coreerr.E("HealthServer.Start", fmt.Sprintf("failed to listen on %s", h.addr), err)
 	}
 
 	h.listener = listener
diff --git a/pidfile.go b/pidfile.go
index 96e7d5b..240c44c 100644
--- a/pidfile.go
+++ b/pidfile.go
@@ -10,6 +10,7 @@ import (
 	"syscall"
 
 	coreio "forge.lthn.ai/core/go-io"
+	coreerr "forge.lthn.ai/core/go-log"
 )
 
 // PIDFile manages a process ID file for single-instance enforcement.
@@ -34,7 +35,7 @@ func (p *PIDFile) Acquire() error {
 		if err == nil && pid > 0 {
 			if proc, err := os.FindProcess(pid); err == nil {
 				if err := proc.Signal(syscall.Signal(0)); err == nil {
-					return fmt.Errorf("another instance is running (PID %d)", pid)
+					return coreerr.E("PIDFile.Acquire", fmt.Sprintf("another instance is running (PID %d)", pid), nil)
 				}
 			}
 		}
@@ -43,13 +44,13 @@ func (p *PIDFile) Acquire() error {
 
 	if dir := filepath.Dir(p.path); dir != "." {
 		if err := coreio.Local.EnsureDir(dir); err != nil {
-			return fmt.Errorf("failed to create PID directory: %w", err)
+			return coreerr.E("PIDFile.Acquire", "failed to create PID directory", err)
 		}
 	}
 
 	pid := os.Getpid()
 	if err := coreio.Local.Write(p.path, strconv.Itoa(pid)); err != nil {
-		return fmt.Errorf("failed to write PID file: %w", err)
+		return coreerr.E("PIDFile.Acquire", "failed to write PID file", err)
 	}
 
 	return nil
diff --git a/process.go b/process.go
index e69c5ee..f9cc222 100644
--- a/process.go
+++ b/process.go
@@ -8,6 +8,8 @@ import (
 	"os/exec"
 	"sync"
 	"time"
+
+	coreerr "forge.lthn.ai/core/go-log"
 )
 
 // Process represents a managed external process.
@@ -87,13 +89,13 @@ func (p *Process) Wait() error {
 	p.mu.RLock()
 	defer p.mu.RUnlock()
 	if p.Status == StatusFailed {
-		return fmt.Errorf("process failed to start: %s", p.ID)
+		return coreerr.E("Process.Wait", fmt.Sprintf("process failed to start: %s", p.ID), nil)
 	}
 	if p.Status == StatusKilled {
-		return fmt.Errorf("process was killed: %s", p.ID)
+		return coreerr.E("Process.Wait", fmt.Sprintf("process was killed: %s", p.ID), nil)
 	}
 	if p.ExitCode != 0 {
-		return fmt.Errorf("process exited with code %d", p.ExitCode)
+		return coreerr.E("Process.Wait", fmt.Sprintf("process exited with code %d", p.ExitCode), nil)
 	}
 	return nil
 }
diff --git a/runner.go b/runner.go
index 8eb1fd5..61eed29 100644
--- a/runner.go
+++ b/runner.go
@@ -2,9 +2,10 @@ package process
 
 import (
 	"context"
-	"errors"
 	"sync"
 	"time"
+
+	coreerr "forge.lthn.ai/core/go-log"
 )
 
 // Runner orchestrates multiple processes with dependencies.
@@ -104,7 +105,7 @@ func (r *Runner) RunAll(ctx context.Context, specs []RunSpec) (*RunAllResult, er
 					Name:    name,
 					Spec:    remaining[name],
 					Skipped: true,
-					Error:   errors.New("circular dependency or missing dependency"),
+					Error:   coreerr.E("Runner.RunAll", "circular dependency or missing dependency", nil),
 				})
 			}
 			break
@@ -136,7 +137,7 @@ func (r *Runner) RunAll(ctx context.Context, specs []RunSpec) (*RunAllResult, er
 						Name:    spec.Name,
 						Spec:    spec,
 						Skipped: true,
-						Error:   errors.New("skipped due to dependency failure"),
+						Error:   coreerr.E("Runner.RunAll", "skipped due to dependency failure", nil),
 					}
 				} else {
 					result = r.runSpec(ctx, spec)
diff --git a/service.go b/service.go
index 661dac9..461d0e1 100644
--- a/service.go
+++ b/service.go
@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"forge.lthn.ai/core/go/pkg/core"
+	coreerr "forge.lthn.ai/core/go-log"
 )
 
 // Default buffer size for process output (1MB).
@@ -20,9 +21,9 @@ const DefaultBufferSize = 1024 * 1024
 
 // Errors
 var (
-	ErrProcessNotFound   = errors.New("process not found")
-	ErrProcessNotRunning = errors.New("process is not running")
-	ErrStdinNotAvailable = errors.New("stdin not available")
+	ErrProcessNotFound   = coreerr.E("", "process not found", nil)
+	ErrProcessNotRunning = coreerr.E("", "process is not running", nil)
+	ErrStdinNotAvailable = coreerr.E("", "stdin not available", nil)
 )
 
 // Service manages process execution with Core IPC integration.
@@ -121,19 +122,19 @@ func (s *Service) StartWithOptions(ctx context.Context, opts RunOptions) (*Proce
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {
 		cancel()
-		return nil, fmt.Errorf("failed to create stdout pipe: %w", err)
+		return nil, coreerr.E("Service.StartWithOptions", "failed to create stdout pipe", err)
 	}
 
 	stderr, err := cmd.StderrPipe()
 	if err != nil {
 		cancel()
-		return nil, fmt.Errorf("failed to create stderr pipe: %w", err)
+		return nil, coreerr.E("Service.StartWithOptions", "failed to create stderr pipe", err)
 	}
 
 	stdin, err := cmd.StdinPipe()
 	if err != nil {
 		cancel()
-		return nil, fmt.Errorf("failed to create stdin pipe: %w", err)
+		return nil, coreerr.E("Service.StartWithOptions", "failed to create stdin pipe", err)
 	}
 
 	// Create output buffer (enabled by default)
@@ -161,7 +162,7 @@ func (s *Service) StartWithOptions(ctx context.Context, opts RunOptions) (*Proce
 	// Start the process
 	if err := cmd.Start(); err != nil {
 		cancel()
-		return nil, fmt.Errorf("failed to start process: %w", err)
+		return nil, coreerr.E("Service.StartWithOptions", "failed to start process", err)
 	}
 
 	// Store process
@@ -327,7 +328,7 @@ func (s *Service) Remove(id string) error {
 	}
 
 	if proc.IsRunning() {
-		return errors.New("cannot remove running process")
+		return coreerr.E("Service.Remove", "cannot remove running process", nil)
 	}
 
 	delete(s.processes, id)
@@ -367,7 +368,7 @@ func (s *Service) Run(ctx context.Context, command string, args ...string) (stri
 
 	output := proc.Output()
 	if proc.ExitCode != 0 {
-		return output, fmt.Errorf("process exited with code %d", proc.ExitCode)
+		return output, coreerr.E("Service.Run", fmt.Sprintf("process exited with code %d", proc.ExitCode), nil)
 	}
 	return output, nil
 }
@@ -383,7 +384,7 @@ func (s *Service) RunWithOptions(ctx context.Context, opts RunOptions) (string,
 
 	output := proc.Output()
 	if proc.ExitCode != 0 {
-		return output, fmt.Errorf("process exited with code %d", proc.ExitCode)
+		return output, coreerr.E("Service.RunWithOptions", fmt.Sprintf("process exited with code %d", proc.ExitCode), nil)
 	}
 	return output, nil
 }