diff --git a/.env.example b/.env.example
index 6356cc90c..d9cb9aabe 100644
--- a/.env.example
+++ b/.env.example
@@ -19,8 +19,8 @@
 # PROBOD_BASE_URL=http://localhost:8080
 # PROBOD_API_ADDR=:8080
 # PROBOD_API_CORS_ALLOWED_ORIGINS=http://localhost:8080,http://localhost:5173,http://localhost:5174
-# PROBOD_TRUST_CENTER_HTTP_ADDR=:80
-# PROBOD_TRUST_CENTER_HTTPS_ADDR=:443
+# PROBOD_TRUST_CENTER_HTTP_ADDR=:10080
+# PROBOD_TRUST_CENTER_HTTPS_ADDR=:10443
 
 # ── Observability ─────────────────────────────────────────────────────
 # PROBOD_METRICS_ADDR=localhost:8081
diff --git a/GNUmakefile b/GNUmakefile
index 8120c8fe8..1cc940285 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -201,18 +201,37 @@ $(CFG_DEV_OAUTH2_KEY):
 cfg/dev.yaml: bin/probod-bootstrap $(CFG_DEV_OAUTH2_KEY) compose/pebble/certs/rootCA.pem $(wildcard $(DEV_ENV))
 	@$(MKDIR) $(@D)
 	set -a; \
+	PROBOD_BASE_URL=http://localhost:8080; \
+	PROBOD_API_ADDR=:8080; \
 	PROBOD_ENCRYPTION_KEY="AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="; \
+	PROBOD_AUTH_COOKIE_NAME=SSID; \
+	PROBOD_AUTH_COOKIE_DOMAIN=localhost; \
 	PROBOD_AUTH_COOKIE_SECRET="this-is-a-secure-secret-for-cookie-signing-at-least-32-bytes"; \
 	PROBOD_AUTH_PASSWORD_PEPPER="this-is-a-secure-pepper-for-password-hashing-at-least-32-bytes"; \
 	PROBOD_AUTH_COOKIE_SECURE=false; \
 	PROBOD_OAUTH2_SERVER_SIGNING_KEY="$$($(CAT) $(CFG_DEV_OAUTH2_KEY))"; \
 	PROBOD_API_CORS_ALLOWED_ORIGINS="http://localhost:8080,http://localhost:5173,http://localhost:5174"; \
+	PROBOD_PG_ADDR=localhost:5432; \
+	PROBOD_PG_USERNAME=postgres; \
+	PROBOD_PG_PASSWORD=postgres; \
+	PROBOD_PG_DATABASE=probod; \
+	PROBOD_TRUST_CENTER_HTTP_ADDR=:10080; \
+	PROBOD_TRUST_CENTER_HTTPS_ADDR=:10443; \
+	PROBOD_AWS_REGION=us-east-1; \
+	PROBOD_AWS_BUCKET=probod; \
 	PROBOD_AWS_ACCESS_KEY_ID=probod; \
 	PROBOD_AWS_SECRET_ACCESS_KEY=thisisnotasecret; \
 	PROBOD_AWS_ENDPOINT=http://127.0.0.1:8333; \
+	PROBOD_SMTP_ADDR=localhost:1025; \
+	PROBOD_MAILER_SENDER_EMAIL=no-reply@notification.getprobo.com; \
+	PROBOD_MAILER_SENDER_NAME=Probo; \
 	PROBOD_OPENAI_API_KEY=thisisnotasecret; \
 	PROBOD_AGENT_THIRD_PARTY_VETTER_PROVIDER=openai; \
+	PROBOD_AGENT_THIRD_PARTY_VETTER_MODEL_NAME=gpt-4o; \
+	PROBOD_CHROME_DP_ADDR=localhost:9222; \
 	PROBOD_ACME_DIRECTORY=https://localhost:14000/dir; \
+	PROBOD_ACME_EMAIL=admin@probo.com; \
+	PROBOD_ACME_ROOT_CA="$$($(CAT) compose/pebble/certs/rootCA.pem)"; \
 	if [ -f $(DEV_ENV) ]; then . $(DEV_ENV); fi; \
 	set +a; \
 	./bin/probod-bootstrap -output $@
diff --git a/pkg/bootstrap/builder.go b/pkg/bootstrap/builder.go
index 344c3eced..821835920 100644
--- a/pkg/bootstrap/builder.go
+++ b/pkg/bootstrap/builder.go
@@ -78,7 +78,7 @@ func (b *Builder) Build() (*probodconfig.FullConfig, error) {
 				Cors: probodconfig.CorsConfig{
 					AllowedOrigins: b.parseOriginsList(b.resolver.getEnv("PROBOD_API_CORS_ALLOWED_ORIGINS")),
 				},
-				ExtraHeaderFields: make(map[string]string),
+				ExtraHeaderFields: nil,
 				GraphQL: probodconfig.GraphQLConfig{
 					ParserTokenLimit:  b.resolver.getEnvIntOrDefault("PROBOD_API_GRAPHQL_PARSER_TOKEN_LIMIT", 15000),
 					ComplexityLimit:   b.resolver.getEnvIntOrDefault("PROBOD_API_GRAPHQL_COMPLEXITY_LIMIT", 2000),
@@ -191,83 +191,78 @@ func (b *Builder) Build() (*probodconfig.FullConfig, error) {
 					ReminderInterval: b.resolver.getEnvIntOrDefault("PROBOD_DOCUMENT_NOTIFICATION_REMINDER_INTERVAL", 86400),
 				},
 			},
-			Agents: probodconfig.AgentsConfig{
-				Providers: map[string]probodconfig.LLMProviderConfig{
-					"openai": {
-						Type:   "openai",
-						APIKey: b.resolver.getEnv("PROBOD_OPENAI_API_KEY"),
+			Agents: func() probodconfig.AgentsConfig {
+				defaultProvider := b.resolver.getEnvOrDefault("PROBOD_AGENT_DEFAULT_PROVIDER", "openai")
+
+				return probodconfig.AgentsConfig{
+					Providers: b.buildLLMProviders(),
+					Default: probodconfig.LLMAgentConfig{
+						Provider:    defaultProvider,
+						ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_DEFAULT_MODEL_NAME", "gpt-4o"),
+						Temperature: new(b.resolver.getEnvFloatOrDefault("PROBOD_AGENT_DEFAULT_TEMPERATURE", 0.1)),
+						MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_DEFAULT_MAX_TOKENS", 4096)),
 					},
-					"anthropic": {
-						Type:   "anthropic",
-						APIKey: b.resolver.getEnv("PROBOD_ANTHROPIC_API_KEY"),
+					Probo: probodconfig.LLMAgentConfig{
+						Provider:    b.resolver.getEnvOrDefault("PROBOD_AGENT_PROBO_PROVIDER", ""),
+						ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_PROBO_MODEL_NAME", ""),
+						Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_PROBO_TEMPERATURE"),
+						MaxTokens:   b.resolver.getEnvIntPtr("PROBOD_AGENT_PROBO_MAX_TOKENS"),
 					},
-				},
-				Default: probodconfig.LLMAgentConfig{
-					Provider:    b.resolver.getEnvOrDefault("PROBOD_AGENT_DEFAULT_PROVIDER", "openai"),
-					ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_DEFAULT_MODEL_NAME", "gpt-4o"),
-					Temperature: new(b.resolver.getEnvFloatOrDefault("PROBOD_AGENT_DEFAULT_TEMPERATURE", 0.1)),
-					MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_DEFAULT_MAX_TOKENS", 4096)),
-				},
-				Probo: probodconfig.LLMAgentConfig{
-					Provider:    b.resolver.getEnvOrDefault("PROBOD_AGENT_PROBO_PROVIDER", ""),
-					ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_PROBO_MODEL_NAME", ""),
-					Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_PROBO_TEMPERATURE"),
-					MaxTokens:   b.resolver.getEnvIntPtr("PROBOD_AGENT_PROBO_MAX_TOKENS"),
-				},
-				EvidenceDescriber: probodconfig.LLMAgentConfig{
-					Provider:    b.resolver.getEnvOrDefault("PROBOD_AGENT_EVIDENCE_DESCRIBER_PROVIDER", ""),
-					ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_EVIDENCE_DESCRIBER_MODEL_NAME", ""),
-					Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_EVIDENCE_DESCRIBER_TEMPERATURE"),
-					MaxTokens:   b.resolver.getEnvIntPtr("PROBOD_AGENT_EVIDENCE_DESCRIBER_MAX_TOKENS"),
-				},
-				ThirdPartyVetter: probodconfig.LLMAgentConfig{
-					Provider:    b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_VETTER_PROVIDER", ""),
-					ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_VETTER_MODEL_NAME", ""),
-					Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_THIRD_PARTY_VETTER_TEMPERATURE"),
-					MaxTokens:   b.resolver.getEnvIntPtr("PROBOD_AGENT_THIRD_PARTY_VETTER_MAX_TOKENS"),
-				},
-				ThirdPartyDisambiguation: probodconfig.LLMAgentConfig{
-					Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_PROVIDER", ""),
-					ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_MODEL_NAME", ""),
-					// The disambiguation agent emits a single id plus a
-					// short rationale, but the budget must leave headroom
-					// for reasoning models whose reasoning tokens count
-					// against max_tokens; too small a budget truncates the
-					// JSON.
-					Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_TEMPERATURE"),
-					MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_MAX_TOKENS", 4096)),
-				},
-				TrackerMapping: probodconfig.LLMAgentConfig{
-					Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_MAPPING_PROVIDER", ""),
-					ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_MAPPING_MODEL_NAME", ""),
-					// The tracker agents emit tiny structured JSON, but
-					// the budget must leave headroom for reasoning
-					// models whose reasoning tokens count against
-					// max_tokens; too small a budget truncates the JSON.
-					Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_TRACKER_MAPPING_TEMPERATURE"),
-					MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_TRACKER_MAPPING_MAX_TOKENS", 4096)),
-				},
-				TrackerEnrichment: probodconfig.LLMAgentConfig{
-					Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_ENRICHMENT_PROVIDER", ""),
-					ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_ENRICHMENT_MODEL_NAME", ""),
-					// See the tracker-mapping note: keep ample headroom so
-					// reasoning models do not truncate the structured JSON.
-					Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_TRACKER_ENRICHMENT_TEMPERATURE"),
-					MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_TRACKER_ENRICHMENT_MAX_TOKENS", 4096)),
-				},
-				CommonThirdPartyEnrichment: probodconfig.LLMAgentConfig{
-					Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_PROVIDER", ""),
-					ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_MODEL_NAME", ""),
-					// Agent B browses pages and emits a moderate structured
-					// output; the budget must leave headroom for reasoning
-					// models whose reasoning tokens count against max_tokens.
-					Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_TEMPERATURE"),
-					MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_MAX_TOKENS", 8192)),
-				},
-				Tools: probodconfig.AgentToolsConfig{
-					FirecrawlAPIKey: b.resolver.getEnv("PROBOD_FIRECRAWL_API_KEY"),
-				},
-			},
+					EvidenceDescriber: probodconfig.LLMAgentConfig{
+						Provider:    b.resolver.getEnvOrDefault("PROBOD_AGENT_EVIDENCE_DESCRIBER_PROVIDER", ""),
+						ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_EVIDENCE_DESCRIBER_MODEL_NAME", ""),
+						Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_EVIDENCE_DESCRIBER_TEMPERATURE"),
+						MaxTokens:   b.resolver.getEnvIntPtr("PROBOD_AGENT_EVIDENCE_DESCRIBER_MAX_TOKENS"),
+					},
+					ThirdPartyVetter: probodconfig.LLMAgentConfig{
+						Provider:    b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_VETTER_PROVIDER", ""),
+						ModelName:   b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_VETTER_MODEL_NAME", ""),
+						Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_THIRD_PARTY_VETTER_TEMPERATURE"),
+						MaxTokens:   b.resolver.getEnvIntPtr("PROBOD_AGENT_THIRD_PARTY_VETTER_MAX_TOKENS"),
+					},
+					ThirdPartyDisambiguation: probodconfig.LLMAgentConfig{
+						Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_PROVIDER", ""),
+						ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_MODEL_NAME", ""),
+						// The disambiguation agent emits a single id plus a
+						// short rationale, but the budget must leave headroom
+						// for reasoning models whose reasoning tokens count
+						// against max_tokens; too small a budget truncates the
+						// JSON.
+						Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_TEMPERATURE"),
+						MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_THIRD_PARTY_DISAMBIGUATION_MAX_TOKENS", 4096)),
+					},
+					TrackerMapping: probodconfig.LLMAgentConfig{
+						Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_MAPPING_PROVIDER", ""),
+						ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_MAPPING_MODEL_NAME", ""),
+						// The tracker agents emit tiny structured JSON, but
+						// the budget must leave headroom for reasoning
+						// models whose reasoning tokens count against
+						// max_tokens; too small a budget truncates the JSON.
+						Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_TRACKER_MAPPING_TEMPERATURE"),
+						MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_TRACKER_MAPPING_MAX_TOKENS", 4096)),
+					},
+					TrackerEnrichment: probodconfig.LLMAgentConfig{
+						Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_ENRICHMENT_PROVIDER", ""),
+						ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_TRACKER_ENRICHMENT_MODEL_NAME", ""),
+						// See the tracker-mapping note: keep ample headroom so
+						// reasoning models do not truncate the structured JSON.
+						Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_TRACKER_ENRICHMENT_TEMPERATURE"),
+						MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_TRACKER_ENRICHMENT_MAX_TOKENS", 4096)),
+					},
+					CommonThirdPartyEnrichment: probodconfig.LLMAgentConfig{
+						Provider:  b.resolver.getEnvOrDefault("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_PROVIDER", ""),
+						ModelName: b.resolver.getEnvOrDefault("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_MODEL_NAME", ""),
+						// Agent B browses pages and emits a moderate structured
+						// output; the budget must leave headroom for reasoning
+						// models whose reasoning tokens count against max_tokens.
+						Temperature: b.resolver.getEnvFloatPtr("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_TEMPERATURE"),
+						MaxTokens:   new(b.resolver.getEnvIntOrDefault("PROBOD_AGENT_COMMON_THIRD_PARTY_ENRICHMENT_MAX_TOKENS", 8192)),
+					},
+					Tools: probodconfig.AgentToolsConfig{
+						FirecrawlAPIKey: b.resolver.getEnv("PROBOD_FIRECRAWL_API_KEY"),
+					},
+				}
+			}(),
 			CustomDomains: probodconfig.CustomDomainsConfig{
 				RenewalInterval:   b.resolver.getEnvIntOrDefault("PROBOD_CUSTOM_DOMAINS_RENEWAL_INTERVAL", 3600),
 				ProvisionInterval: b.resolver.getEnvIntOrDefault("PROBOD_CUSTOM_DOMAINS_PROVISION_INTERVAL", 30),
@@ -647,6 +642,30 @@ func (b *Builder) getPgCACertBundle() string {
 	return b.resolver.getEnv("PROBOD_PG_CA_BUNDLE")
 }
 
+func (b *Builder) buildLLMProviders() map[string]probodconfig.LLMProviderConfig {
+	providers := map[string]probodconfig.LLMProviderConfig{}
+
+	if apiKey := b.resolver.getEnv("PROBOD_OPENAI_API_KEY"); apiKey != "" {
+		providers["openai"] = probodconfig.LLMProviderConfig{
+			Type:   "openai",
+			APIKey: apiKey,
+		}
+	}
+
+	if apiKey := b.resolver.getEnv("PROBOD_ANTHROPIC_API_KEY"); apiKey != "" {
+		providers["anthropic"] = probodconfig.LLMProviderConfig{
+			Type:   "anthropic",
+			APIKey: apiKey,
+		}
+	}
+
+	if len(providers) == 0 {
+		return nil
+	}
+
+	return providers
+}
+
 func (b *Builder) parseOriginsList(s string) []string {
 	s = strings.TrimSpace(s)
 	if s == "" {
diff --git a/pkg/bootstrap/builder_test.go b/pkg/bootstrap/builder_test.go
index 38bda637b..0c093caa3 100644
--- a/pkg/bootstrap/builder_test.go
+++ b/pkg/bootstrap/builder_test.go
@@ -214,6 +214,7 @@ func TestBuilder_Build_Defaults(t *testing.T) {
 	assert.Equal(t, "gpt-4o", cfg.Probod.Agents.Default.ModelName)
 	assert.Equal(t, new(0.1), cfg.Probod.Agents.Default.Temperature)
 	assert.Equal(t, new(4096), cfg.Probod.Agents.Default.MaxTokens)
+	assert.Nil(t, cfg.Probod.Agents.Providers)
 	// Agents config — per-agent overrides are empty (inherit from default)
 	assert.Empty(t, cfg.Probod.Agents.Probo.Provider)
 	assert.Empty(t, cfg.Probod.Agents.Probo.ModelName)
diff --git a/pkg/bootstrap/write.go b/pkg/bootstrap/write.go
index f92436652..0b3535c28 100644
--- a/pkg/bootstrap/write.go
+++ b/pkg/bootstrap/write.go
@@ -37,28 +37,21 @@ func WriteConfig(cfg *probodconfig.FullConfig, path string, format Format) error
 		return fmt.Errorf("create directory %s: %w", dir, err)
 	}
 
-	data, err := yaml.Marshal(cfg)
-	if err != nil {
-		return fmt.Errorf("marshal config: %w", err)
-	}
-
-	var tree any
-	if err := yaml.Unmarshal(data, &tree); err != nil {
-		return fmt.Errorf("unmarshal config: %w", err)
-	}
-
-	pruned := pruneEmptyStrings(tree)
+	var (
+		data []byte
+		err  error
+	)
 
 	switch format {
 	case FormatJSON:
-		data, err = json.MarshalIndent(pruned, "", "  ")
+		data, err = json.MarshalIndent(cfg, "", "  ")
 		if err != nil {
-			return fmt.Errorf("marshal pruned config as json: %w", err)
+			return fmt.Errorf("marshal config as json: %w", err)
 		}
 	case FormatYAML:
-		data, err = yaml.Marshal(pruned)
+		data, err = yaml.Marshal(cfg)
 		if err != nil {
-			return fmt.Errorf("marshal pruned config as yaml: %w", err)
+			return fmt.Errorf("marshal config as yaml: %w", err)
 		}
 	default:
 		return fmt.Errorf("unsupported config format: %q", format)
@@ -70,28 +63,3 @@ func WriteConfig(cfg *probodconfig.FullConfig, path string, format Format) error
 
 	return nil
 }
-
-func pruneEmptyStrings(value any) any {
-	switch v := value.(type) {
-	case map[string]any:
-		for key, child := range v {
-			if s, ok := child.(string); ok && s == "" {
-				delete(v, key)
-
-				continue
-			}
-
-			v[key] = pruneEmptyStrings(child)
-		}
-
-		return v
-	case []any:
-		for i, child := range v {
-			v[i] = pruneEmptyStrings(child)
-		}
-
-		return v
-	default:
-		return v
-	}
-}
diff --git a/pkg/bootstrap/write_test.go b/pkg/bootstrap/write_test.go
index 3b9476963..f2b570736 100644
--- a/pkg/bootstrap/write_test.go
+++ b/pkg/bootstrap/write_test.go
@@ -86,7 +86,7 @@ func TestWriteConfig_FilePermissions(t *testing.T) {
 	assert.Equal(t, os.FileMode(0600), info.Mode().Perm())
 }
 
-func TestWriteConfig_DropsEmptyStrings(t *testing.T) {
+func TestWriteConfig_OmitsOptionalFields(t *testing.T) {
 	tmpDir := t.TempDir()
 	configPath := filepath.Join(tmpDir, "probod.yml")
 
@@ -96,9 +96,8 @@ func TestWriteConfig_DropsEmptyStrings(t *testing.T) {
 			Tracing: probodconfig.TracingConfig{Addr: ""},
 		},
 		Probod: probodconfig.Config{
-			BaseURL:       "http://localhost:8080",
-			EncryptionKey: "",
-			ChromeDPAddr:  "",
+			BaseURL:      "http://localhost:8080",
+			ChromeDPAddr: "",
 			Pg: probodconfig.PgConfig{
 				Addr:     "localhost:5432",
 				Username: "postgres",
@@ -124,8 +123,8 @@ func TestWriteConfig_DropsEmptyStrings(t *testing.T) {
 	require.True(t, ok)
 
 	assert.Equal(t, "http://localhost:8080", probod["base-url"])
-	assert.NotContains(t, probod, "encryption-key")
 	assert.NotContains(t, probod, "chrome-dp-addr")
+	assert.NotContains(t, probod, "esign")
 
 	pg, ok := probod["pg"].(map[string]any)
 	require.True(t, ok)
@@ -146,12 +145,168 @@ func TestWriteConfig_DropsEmptyStrings(t *testing.T) {
 	tracing, ok := unit["tracing"].(map[string]any)
 	require.True(t, ok)
 	assert.NotContains(t, tracing, "addr")
+}
 
-	loaded := probodconfig.FullConfig{}
-	err = yaml.Unmarshal(data, &loaded)
+func TestWriteConfig_OmitsEmptyOptionalBlocks(t *testing.T) {
+	tmpDir := t.TempDir()
+	configPath := filepath.Join(tmpDir, "probod.yml")
+
+	cfg := &probodconfig.FullConfig{
+		Probod: probodconfig.Config{
+			BaseURL:       "http://localhost:8080",
+			EncryptionKey: "test-key",
+			Api: probodconfig.APIConfig{
+				Addr: ":8080",
+			},
+			Auth: probodconfig.AuthConfig{
+				Cookie: probodconfig.CookieConfig{
+					Name:   "SSID",
+					Secret: "secret",
+				},
+				Password: probodconfig.PasswordConfig{
+					Pepper: "pepper",
+				},
+			},
+			TrustCenter: probodconfig.TrustCenterConfig{
+				HTTPAddr: ":80",
+			},
+			CustomDomains: probodconfig.CustomDomainsConfig{
+				RenewalInterval: 3600,
+			},
+			Agents: probodconfig.AgentsConfig{
+				Default: probodconfig.LLMAgentConfig{
+					Provider:  "openai",
+					ModelName: "gpt-4o",
+				},
+				ThirdPartyDisambiguation: probodconfig.LLMAgentConfig{
+					MaxTokens: new(4096),
+				},
+			},
+		},
+	}
+
+	err := WriteConfig(cfg, configPath, FormatYAML)
 	require.NoError(t, err)
-	assert.Equal(t, cfg.Probod.BaseURL, loaded.Probod.BaseURL)
-	assert.Empty(t, loaded.Probod.EncryptionKey)
+
+	data, err := os.ReadFile(configPath)
+	require.NoError(t, err)
+
+	var tree map[string]any
+
+	err = yaml.Unmarshal(data, &tree)
+	require.NoError(t, err)
+
+	probod, ok := tree["probod"].(map[string]any)
+	require.True(t, ok)
+
+	assert.NotContains(t, probod, "esign")
+
+	api, ok := probod["api"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, api, "cors")
+	assert.NotContains(t, api, "proxy-protocol")
+	assert.NotContains(t, api, "extra-header-fields")
+
+	auth, ok := probod["auth"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, auth, "google")
+	assert.NotContains(t, auth, "microsoft")
+
+	customDomains, ok := probod["custom-domains"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, customDomains, "acme")
+
+	trustCenter, ok := probod["trust-center"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, trustCenter, "proxy-protocol")
+
+	llm, ok := probod["llm"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, llm, "probo")
+	assert.NotContains(t, llm, "third-party-disambiguation")
+	assert.NotContains(t, llm, "tools")
+}
+
+func TestWriteConfig_OmitsEmptyProxyProtocolAndCorsSlices(t *testing.T) {
+	tmpDir := t.TempDir()
+	configPath := filepath.Join(tmpDir, "probod.yml")
+
+	cfg := &probodconfig.FullConfig{
+		Probod: probodconfig.Config{
+			BaseURL: "http://localhost:8080",
+			Api: probodconfig.APIConfig{
+				Addr: ":8080",
+				ProxyProtocol: probodconfig.ProxyProtocolConfig{
+					TrustedProxies: []string{},
+				},
+				Cors: probodconfig.CorsConfig{
+					AllowedOrigins: []string{},
+				},
+			},
+			TrustCenter: probodconfig.TrustCenterConfig{
+				HTTPAddr: ":10080",
+				ProxyProtocol: probodconfig.ProxyProtocolConfig{
+					TrustedProxies: make([]string, 0),
+				},
+			},
+		},
+	}
+
+	err := WriteConfig(cfg, configPath, FormatYAML)
+	require.NoError(t, err)
+
+	data, err := os.ReadFile(configPath)
+	require.NoError(t, err)
+
+	var tree map[string]any
+
+	err = yaml.Unmarshal(data, &tree)
+	require.NoError(t, err)
+
+	probod, ok := tree["probod"].(map[string]any)
+	require.True(t, ok)
+
+	api, ok := probod["api"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, api, "proxy-protocol")
+	assert.NotContains(t, api, "cors")
+
+	trustCenter, ok := probod["trust-center"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, trustCenter, "proxy-protocol")
+}
+
+func TestWriteConfig_OmitsEmptyExtraHeaderFieldsMap(t *testing.T) {
+	tmpDir := t.TempDir()
+	configPath := filepath.Join(tmpDir, "probod.yml")
+
+	cfg := &probodconfig.FullConfig{
+		Probod: probodconfig.Config{
+			BaseURL: "http://localhost:8080",
+			Api: probodconfig.APIConfig{
+				Addr:              ":8080",
+				ExtraHeaderFields: map[string]string{},
+			},
+		},
+	}
+
+	err := WriteConfig(cfg, configPath, FormatYAML)
+	require.NoError(t, err)
+
+	data, err := os.ReadFile(configPath)
+	require.NoError(t, err)
+
+	var tree map[string]any
+
+	err = yaml.Unmarshal(data, &tree)
+	require.NoError(t, err)
+
+	probod, ok := tree["probod"].(map[string]any)
+	require.True(t, ok)
+
+	api, ok := probod["api"].(map[string]any)
+	require.True(t, ok)
+	assert.NotContains(t, api, "extra-header-fields")
 }
 
 func TestWriteConfig_CompleteConfig(t *testing.T) {
@@ -178,7 +333,6 @@ func TestWriteConfig_CompleteConfig(t *testing.T) {
 				Cors: probodconfig.CorsConfig{
 					AllowedOrigins: []string{"http://localhost:8080"},
 				},
-				ExtraHeaderFields: map[string]string{},
 			},
 			Pg: probodconfig.PgConfig{
 				Addr:                   "localhost:5432",
@@ -256,7 +410,7 @@ func TestWriteConfig_JSON(t *testing.T) {
 	probod, ok := tree["probod"].(map[string]any)
 	require.True(t, ok)
 	assert.Equal(t, "http://localhost:8080", probod["base-url"])
-	assert.NotContains(t, probod, "encryption-key")
+	assert.Equal(t, "", probod["encryption-key"])
 
 	var loaded probodconfig.FullConfig
 
diff --git a/pkg/probodconfig/api_config.go b/pkg/probodconfig/api_config.go
index eceeb9bd6..4a912a6b0 100644
--- a/pkg/probodconfig/api_config.go
+++ b/pkg/probodconfig/api_config.go
@@ -15,11 +15,19 @@
 package probodconfig
 
 type CorsConfig struct {
-	AllowedOrigins []string `json:"allowed-origins"`
+	AllowedOrigins []string `json:"allowed-origins,omitzero,omitempty"`
+}
+
+func (c CorsConfig) IsZero() bool {
+	return len(c.AllowedOrigins) == 0
 }
 
 type ProxyProtocolConfig struct {
-	TrustedProxies []string `json:"trusted-proxies"`
+	TrustedProxies []string `json:"trusted-proxies,omitzero,omitempty"`
+}
+
+func (c ProxyProtocolConfig) IsZero() bool {
+	return len(c.TrustedProxies) == 0
 }
 
 type GraphQLConfig struct {
@@ -30,9 +38,9 @@ type GraphQLConfig struct {
 }
 
 type APIConfig struct {
-	Addr              string              `json:"addr"`
-	ProxyProtocol     ProxyProtocolConfig `json:"proxy-protocol"`
-	Cors              CorsConfig          `json:"cors"`
-	ExtraHeaderFields map[string]string   `json:"extra-header-fields"`
-	GraphQL           GraphQLConfig       `json:"graphql"`
+	Addr              string              `json:"addr,omitempty"`
+	ProxyProtocol     ProxyProtocolConfig `json:"proxy-protocol,omitzero"`
+	Cors              CorsConfig          `json:"cors,omitzero"`
+	ExtraHeaderFields map[string]string   `json:"extra-header-fields,omitzero,omitempty"`
+	GraphQL           GraphQLConfig       `json:"graphql,omitzero"`
 }
diff --git a/pkg/probodconfig/auth_config.go b/pkg/probodconfig/auth_config.go
index a936d578c..a1c04370d 100644
--- a/pkg/probodconfig/auth_config.go
+++ b/pkg/probodconfig/auth_config.go
@@ -27,8 +27,8 @@ type AuthConfig struct {
 	PasswordResetTokenValidity          int                `json:"password-reset-token-validity"`
 	MagicLinkTokenValidity              int                `json:"magic-link-token-validity"`
 	SAML                                SAMLConfig         `json:"saml"`
-	Google                              OIDCProviderConfig `json:"google"`
-	Microsoft                           OIDCProviderConfig `json:"microsoft"`
+	Google                              OIDCProviderConfig `json:"google,omitzero"`
+	Microsoft                           OIDCProviderConfig `json:"microsoft,omitzero"`
 	OAuth2Server                        OAuth2ServerConfig `json:"oauth2-server"`
 }
 
@@ -38,7 +38,7 @@ type OAuth2ServerConfig struct {
 	RefreshTokenDuration      int                      `json:"refresh-token-duration"`
 	AuthorizationCodeDuration int                      `json:"authorization-code-duration"`
 	DeviceCodeDuration        int                      `json:"device-code-duration"`
-	CIMDAllowedClientIDs      []string                 `json:"cimd-allowed-client-ids"`
+	CIMDAllowedClientIDs      []string                 `json:"cimd-allowed-client-ids,omitempty"`
 }
 
 type OAuth2SigningKeyConfig struct {
@@ -48,10 +48,10 @@ type OAuth2SigningKeyConfig struct {
 }
 
 type CookieConfig struct {
-	Domain   string `json:"domain"`
+	Domain   string `json:"domain,omitempty"`
 	Secret   string `json:"secret"`
 	Duration int    `json:"duration"`
-	Name     string `json:"name"`
+	Name     string `json:"name,omitempty"`
 	Secure   bool   `json:"secure"`
 }
 
diff --git a/pkg/probodconfig/aws_config.go b/pkg/probodconfig/aws_config.go
index c0138b5dc..950e7d886 100644
--- a/pkg/probodconfig/aws_config.go
+++ b/pkg/probodconfig/aws_config.go
@@ -15,10 +15,10 @@
 package probodconfig
 
 type AWSConfig struct {
-	Region          string `json:"region"`
-	Bucket          string `json:"bucket"`
-	AccessKeyID     string `json:"access-key-id"`
-	SecretAccessKey string `json:"secret-access-key"`
-	Endpoint        string `json:"endpoint"`
+	Region          string `json:"region,omitempty"`
+	Bucket          string `json:"bucket,omitempty"`
+	AccessKeyID     string `json:"access-key-id,omitempty"`
+	SecretAccessKey string `json:"secret-access-key,omitempty"`
+	Endpoint        string `json:"endpoint,omitempty"`
 	UsePathStyle    bool   `json:"use-path-style"`
 }
diff --git a/pkg/probodconfig/config.go b/pkg/probodconfig/config.go
index 2c15a982e..d0e3182e5 100644
--- a/pkg/probodconfig/config.go
+++ b/pkg/probodconfig/config.go
@@ -35,7 +35,7 @@ type (
 
 	// TracingConfig contains tracing configuration.
 	TracingConfig struct {
-		Addr          string `json:"addr"`
+		Addr          string `json:"addr,omitempty"`
 		MaxBatchSize  int    `json:"max-batch-size"`
 		BatchTimeout  int    `json:"batch-timeout"`
 		ExportTimeout int    `json:"export-timeout"`
@@ -44,12 +44,12 @@ type (
 
 	// ESignConfig contains electronic signature configuration.
 	ESignConfig struct {
-		TSAURL string `json:"tsa-url"`
+		TSAURL string `json:"tsa-url,omitempty"`
 	}
 
 	// Config represents the probod application configuration.
 	Config struct {
-		BaseURL           string                        `json:"base-url"`
+		BaseURL           string                        `json:"base-url,omitempty"`
 		EncryptionKey     string                        `json:"encryption-key"`
 		Pg                PgConfig                      `json:"pg"`
 		Api               APIConfig                     `json:"api"`
@@ -57,7 +57,7 @@ type (
 		TrustCenter       TrustCenterConfig             `json:"trust-center"`
 		AWS               AWSConfig                     `json:"aws"`
 		Notifications     NotificationsConfig           `json:"notifications"`
-		Connectors        []ConnectorConfig             `json:"connectors"`
+		Connectors        []ConnectorConfig             `json:"connectors,omitempty"`
 		Agents            AgentsConfig                  `json:"llm"`
 		EvidenceDescriber EvidenceDescriberConfig       `json:"evidence-describer"`
 		ThirdPartyVetting ThirdPartyVettingWorkerConfig `json:"third-party-vetting-worker"`
@@ -66,17 +66,17 @@ type (
 		CommonPatternEnrichmentWorker    CommonPatternEnrichmentWorkerConfig    `json:"common-pattern-enrichment-worker"`
 		CommonThirdPartyEnrichmentWorker CommonThirdPartyEnrichmentWorkerConfig `json:"common-third-party-enrichment-worker"`
 
-		ChromeDPAddr  string              `json:"chrome-dp-addr"`
+		ChromeDPAddr  string              `json:"chrome-dp-addr,omitempty"`
 		CustomDomains CustomDomainsConfig `json:"custom-domains"`
 		SCIMBridge    SCIMBridgeConfig    `json:"scim-bridge"`
-		ESign         ESignConfig         `json:"esign"`
+		ESign         ESignConfig         `json:"esign,omitzero"`
 		Branding      bool                `json:"branding"`
 	}
 
 	// TrustCenterConfig contains trust center server configuration.
 	TrustCenterConfig struct {
-		HTTPAddr      string              `json:"http-addr"`
-		HTTPSAddr     string              `json:"https-addr"`
-		ProxyProtocol ProxyProtocolConfig `json:"proxy-protocol"`
+		HTTPAddr      string              `json:"http-addr,omitempty"`
+		HTTPSAddr     string              `json:"https-addr,omitempty"`
+		ProxyProtocol ProxyProtocolConfig `json:"proxy-protocol,omitzero"`
 	}
 )
diff --git a/pkg/probodconfig/custom_domains_config.go b/pkg/probodconfig/custom_domains_config.go
index 50046bbd1..32adf6931 100644
--- a/pkg/probodconfig/custom_domains_config.go
+++ b/pkg/probodconfig/custom_domains_config.go
@@ -17,16 +17,16 @@ package probodconfig
 type CustomDomainsConfig struct {
 	RenewalInterval   int        `json:"renewal-interval"`
 	ProvisionInterval int        `json:"provision-interval"`
-	ResolverAddr      string     `json:"resolver-addr"`
+	ResolverAddr      string     `json:"resolver-addr,omitempty"`
 	CnameTarget       string     `json:"cname-target"`
 	CAAIssuerDomain   string     `json:"caa-issuer-domain"`
-	ACME              ACMEConfig `json:"acme"`
+	ACME              ACMEConfig `json:"acme,omitzero"`
 }
 
 type ACMEConfig struct {
-	Directory  string `json:"directory"`
-	Email      string `json:"email"`
-	KeyType    string `json:"key-type"`
-	AccountKey string `json:"account-key"`
-	RootCA     string `json:"root-ca"`
+	Directory  string `json:"directory,omitempty"`
+	Email      string `json:"email,omitempty"`
+	KeyType    string `json:"key-type,omitempty"`
+	AccountKey string `json:"account-key,omitempty"`
+	RootCA     string `json:"root-ca,omitempty"`
 }
diff --git a/pkg/probodconfig/llm_config.go b/pkg/probodconfig/llm_config.go
index f81d43bab..ac121288e 100644
--- a/pkg/probodconfig/llm_config.go
+++ b/pkg/probodconfig/llm_config.go
@@ -18,17 +18,17 @@ type (
 	// LLMProviderConfig holds authentication and connection settings for an
 	// LLM provider (e.g. OpenAI, Anthropic).
 	LLMProviderConfig struct {
-		Type   string `json:"type"`    // "openai", "anthropic", "bedrock"
-		APIKey string `json:"api-key"` // for OpenAI and Anthropic
+		Type   string `json:"type"`              // "openai", "anthropic", "bedrock"
+		APIKey string `json:"api-key,omitempty"` // for OpenAI and Anthropic
 	}
 
 	// LLMAgentConfig holds model parameters for a single agent. Provider
 	// references one of the keys in AgentsConfig.Providers.
 	LLMAgentConfig struct {
-		Provider    string   `json:"provider"` // key into AgentsConfig.Providers
-		ModelName   string   `json:"model-name"`
-		Temperature *float64 `json:"temperature"`
-		MaxTokens   *int     `json:"max-tokens"`
+		Provider    string   `json:"provider,omitempty"` // key into AgentsConfig.Providers
+		ModelName   string   `json:"model-name,omitempty"`
+		Temperature *float64 `json:"temperature,omitempty"`
+		MaxTokens   *int     `json:"max-tokens,omitempty"`
 	}
 
 	// EvidenceDescriberConfig holds worker-side tuning for the evidence
@@ -95,26 +95,38 @@ type (
 	// AgentToolsConfig holds API keys and settings for external tools
 	// that agents can use (web search, scraping, etc.).
 	AgentToolsConfig struct {
-		FirecrawlAPIKey string `json:"firecrawl-api-key"`
+		FirecrawlAPIKey string `json:"firecrawl-api-key,omitempty"`
 	}
 
 	// AgentsConfig groups LLM provider credentials and per-agent model
 	// settings. Default is used as a fallback when an agent-specific field
 	// is zero-valued.
 	AgentsConfig struct {
-		Providers                  map[string]LLMProviderConfig `json:"providers"`
+		Providers                  map[string]LLMProviderConfig `json:"providers,omitempty"`
 		Default                    LLMAgentConfig               `json:"defaults"`
-		Probo                      LLMAgentConfig               `json:"probo"`
-		EvidenceDescriber          LLMAgentConfig               `json:"evidence-describer"`
-		ThirdPartyVetter           LLMAgentConfig               `json:"third-party-vetter"`
-		ThirdPartyDisambiguation   LLMAgentConfig               `json:"third-party-disambiguation"`
-		TrackerMapping             LLMAgentConfig               `json:"tracker-mapping"`
-		TrackerEnrichment          LLMAgentConfig               `json:"tracker-enrichment"`
-		CommonThirdPartyEnrichment LLMAgentConfig               `json:"common-third-party-enrichment"`
-		Tools                      AgentToolsConfig             `json:"tools"`
+		Probo                      LLMAgentConfig               `json:"probo,omitzero"`
+		EvidenceDescriber          LLMAgentConfig               `json:"evidence-describer,omitzero"`
+		ThirdPartyVetter           LLMAgentConfig               `json:"third-party-vetter,omitzero"`
+		ThirdPartyDisambiguation   LLMAgentConfig               `json:"third-party-disambiguation,omitzero"`
+		TrackerMapping             LLMAgentConfig               `json:"tracker-mapping,omitzero"`
+		TrackerEnrichment          LLMAgentConfig               `json:"tracker-enrichment,omitzero"`
+		CommonThirdPartyEnrichment LLMAgentConfig               `json:"common-third-party-enrichment,omitzero"`
+		Tools                      AgentToolsConfig             `json:"tools,omitzero"`
 	}
 )
 
+func (c LLMProviderConfig) IsZero() bool {
+	return c.APIKey == ""
+}
+
+func (c LLMAgentConfig) IsZero() bool {
+	return c.Provider == "" && c.ModelName == ""
+}
+
+func (c AgentToolsConfig) IsZero() bool {
+	return c.FirecrawlAPIKey == ""
+}
+
 // ResolveAgent returns a fully populated LLMAgentConfig by filling in
 // zero-valued fields from the default config.
 func (c *AgentsConfig) ResolveAgent(agent LLMAgentConfig) LLMAgentConfig {
diff --git a/pkg/probodconfig/mailer_config.go b/pkg/probodconfig/mailer_config.go
index d9d91b0dd..a4a5fdbaf 100644
--- a/pkg/probodconfig/mailer_config.go
+++ b/pkg/probodconfig/mailer_config.go
@@ -16,15 +16,15 @@ package probodconfig
 
 type MailerConfig struct {
 	MailerInterval int        `json:"mailer-interval"`
-	SenderName     string     `json:"sender-name"`
-	SenderEmail    string     `json:"sender-email"`
-	SMTP           SMTPConfig `json:"smtp"`
+	SenderName     string     `json:"sender-name,omitempty"`
+	SenderEmail    string     `json:"sender-email,omitempty"`
+	SMTP           SMTPConfig `json:"smtp,omitzero"`
 }
 
 type SMTPConfig struct {
-	Addr        string `json:"addr"`
-	User        string `json:"user"`
-	Password    string `json:"password"`
+	Addr        string `json:"addr,omitempty"`
+	User        string `json:"user,omitempty"`
+	Password    string `json:"password,omitempty"`
 	TLSRequired bool   `json:"tls-required"`
-	HelloName   string `json:"hello-name"`
+	HelloName   string `json:"hello-name,omitempty"`
 }
diff --git a/pkg/probodconfig/oidc_config.go b/pkg/probodconfig/oidc_config.go
index ad1dd69e1..59fe34531 100644
--- a/pkg/probodconfig/oidc_config.go
+++ b/pkg/probodconfig/oidc_config.go
@@ -15,7 +15,11 @@
 package probodconfig
 
 type OIDCProviderConfig struct {
-	ClientID     string `json:"client-id"`
-	ClientSecret string `json:"client-secret"`
-	Enabled      bool   `json:"enabled"`
+	ClientID     string `json:"client-id,omitempty"`
+	ClientSecret string `json:"client-secret,omitempty"`
+	Enabled      bool   `json:"enabled,omitempty"`
+}
+
+func (c OIDCProviderConfig) IsZero() bool {
+	return c.ClientID == "" && c.ClientSecret == ""
 }
diff --git a/pkg/probodconfig/pg_config.go b/pkg/probodconfig/pg_config.go
index f75dc127b..de70a977c 100644
--- a/pkg/probodconfig/pg_config.go
+++ b/pkg/probodconfig/pg_config.go
@@ -23,17 +23,17 @@ import (
 )
 
 type PgConfig struct {
-	Addr                         string `json:"addr"`
-	Username                     string `json:"username"`
-	Password                     string `json:"password"`
-	Database                     string `json:"database"`
+	Addr                         string `json:"addr,omitempty"`
+	Username                     string `json:"username,omitempty"`
+	Password                     string `json:"password,omitempty"`
+	Database                     string `json:"database,omitempty"`
 	PoolSize                     int32  `json:"pool-size"`
 	MinPoolSize                  int32  `json:"min-pool-size"`
 	MaxConnIdleTimeSeconds       int    `json:"max-conn-idle-time-seconds"`
 	MaxConnLifetimeSeconds       int    `json:"max-conn-lifetime-seconds"`
 	MaxConnLifetimeJitterSeconds int    `json:"max-conn-lifetime-jitter-seconds"`
 	HealthCheckPeriodSeconds     int    `json:"health-check-period-seconds"`
-	CACertBundle                 string `json:"ca-cert-bundle"`
+	CACertBundle                 string `json:"ca-cert-bundle,omitempty"`
 	Debug                        bool   `json:"debug"`
 }
 
diff --git a/pkg/probodconfig/saml_config.go b/pkg/probodconfig/saml_config.go
index 7caf19688..8cb098177 100644
--- a/pkg/probodconfig/saml_config.go
+++ b/pkg/probodconfig/saml_config.go
@@ -24,7 +24,7 @@ type SAMLConfig struct {
 	Certificate                       string `json:"certificate"`
 	PrivateKey                        string `json:"private-key"`
 	DomainVerificationIntervalSeconds int    `json:"domain-verification-interval-seconds"`
-	DomainVerificationResolverAddr    string `json:"domain-verification-resolver-addr"`
+	DomainVerificationResolverAddr    string `json:"domain-verification-resolver-addr,omitempty"`
 }
 
 func (c SAMLConfig) SessionDurationTime() time.Duration {
diff --git a/pkg/probodconfig/slack_config.go b/pkg/probodconfig/slack_config.go
index 452ffc321..602757d7e 100644
--- a/pkg/probodconfig/slack_config.go
+++ b/pkg/probodconfig/slack_config.go
@@ -16,5 +16,5 @@ package probodconfig
 
 type SlackConfig struct {
 	SenderInterval int    `json:"sender-interval"`
-	SigningSecret  string `json:"signing-secret"`
+	SigningSecret  string `json:"signing-secret,omitempty"`
 }