management/store — persistence for agent-network entities

Risk level: Medium — six brand-new tables behind AutoMigrate, one upsert-counter table that runs on the request hot path, and one column carrying an encrypted secret. Backward-compat impact: Additive (six new tables created by AutoMigrate; the Store interface gains 23 methods, but no existing column/index is touched).

Module boundary

This module is the persistence layer for the Agent Network feature. Everything the management server stores about LLM proxying — providers, policies, guardrails, the per-account settings row, a usage-counter table written on every proxied LLM request, and the account-budget rules — flows through the methods added to store.Store. The module owns six tables, six entity types from management/server/agentnetwork/types, and a single hot-path upsert (IncrementAgentNetworkConsumption) consumed by the proxy fleet.

Out of scope here: the catalog of provider definitions (compiled-in, no DB), the synthesizer/manager built on top of these CRUDs (covered in 21-management-agentnetwork.md), and the HTTP handlers that translate API requests into Save/Delete calls.

Files

Tables added / migrations

All six tables are created by db.AutoMigrate invoked from NewSqlStore at sql_store.go:133-143. There is no hand-rolled SQL migration script — the schema is whatever GORM derives from the struct tags.

• agent_network_providers — Provider.TableName() at provider.go:76. PK id, index on account_id, named index idx_agent_network_provider on provider_id. Carries an at-rest-encrypted api_key and ed25519 session_private_key (provider.go:35,56). extra_values and models are JSON blobs (serializer:json).
• agent_network_policies — Policy.TableName() at policy.go:70. PK id, index on account_id. JSON columns: source_groups, destination_provider_ids, guardrail_ids, limits.
• agent_network_guardrails — Guardrail.TableName() at guardrail.go:41. PK id, index on account_id. JSON checks.
• agent_network_settings — Settings.TableName() at settings.go:33. PK account_id (one row per account), named index idx_agent_network_settings_cluster_subdomain on subdomain only — the index name implies a composite, but only one column is tagged.
• agent_network_consumption — Consumption.TableName() at consumption.go:46. Composite PK across (account_id, dim_kind, dim_id, window_seconds, window_start_utc) — the same tuple the upsert keys on.
• agent_network_budget_rules — AccountBudgetRule.TableName() at budgetrule.go:35. PK id, index on account_id. JSON target_groups, target_users, limits.

CRUD surface added

Provider, Policy, Guardrail, BudgetRule follow the same pattern: Get<Kind>ByID, GetAccount<Kind> (list), Save<Kind> (upsert), Delete<Kind>, with account-scoping enforced by the existing accountAndIDQueryCondition / accountIDCondition constants (sql_store.go:59-62). Provider additionally exposes GetAllAgentNetworkProviders (cross-account, used by the synthesizer). Settings exposes Get/GetByCluster/Save (no delete — one row per account, created on first save). Consumption exposes the upsert Increment, a point Get, and a cross-window List.

Architecture & flow

flowchart LR
    handlers["HTTP handlers
(management/server/agentnetwork)"] -->|Save/Delete| iface["Store interface
store.go:328-354"]
    manager["agentnetwork.Manager"] -->|Get*| iface
    synth["synthesizer
(global)"] -->|GetAllAgentNetworkProviders| iface
    proxy["proxy fleet
(hot path)"] -->|IncrementAgentNetworkConsumption| iface
    iface --> sql["SqlStore methods
sql_store_agentnetwork.go"]
    iface -.gomock.-> mock["MockStore
store_mock_agentnetwork.go"]
    sql --> gorm["gorm.DB"]
    gorm --> tables[("6 tables
agent_network_*")]
    sql --> enc["crypt.FieldEncrypt
(provider only)"]

Reads decrypt provider secrets in-place; writes do provider.Copy().EncryptSensitiveData(...) before db.Save so the caller's in-memory object keeps the plaintext api_key (sql_store_agentnetwork.go:88-102). Every list/get takes a LockingStrength and applies clause.Locking{Strength: ...} when non-None — matching the rest of the store. The upsert path uses clause.OnConflict with gorm.Expr server-side increments so concurrent proxy nodes converge without read-modify-write races (sql_store_agentnetwork.go:321-335).

Invariants enforced at the store layer

• Account scoping. Every entity-by-ID method keys on account_id = ? and id = ?; no cross-tenant leak path through the API is reachable as long as callers always pass the auth'd accountID (sql_store_agentnetwork.go:70,141,201,429).
• NotFound mapping. gorm.ErrRecordNotFound is translated to typed status.NewAgentNetwork*NotFoundError; Delete* returns NotFound when RowsAffected == 0 (sql_store_agentnetwork.go:111-113,171-173,231-233,461-463).
• Provider secret encryption at rest. SaveAgentNetworkProvider always encrypts before persist; Get* always decrypts after read. The plaintext api_key never reaches the DB through this layer (sql_store_agentnetwork.go:31,54,80,90).
• Consumption monotonicity. The upsert only ever issues col = col + ? for the three counter columns — no decrement path exists (sql_store_agentnetwork.go:330-332).
• Window alignment is the caller's responsibility. The store stamps WindowStartUTC as-passed; alignment to epoch happens in types.WindowStart at consumption.go:51-58.
• Settings has no Delete. Intentional — one row per account, created on first save; the row sticks around for the account lifetime.

Things to scrutinize

Correctness

• SaveAgentNetworkProvider saves the copy (sql_store_agentnetwork.go:95). The caller's in-memory pointer therefore keeps plaintext api_key and any CreatedAt/UpdatedAt gorm autofills land on the copy, not the original. Callers that need synced timestamps must re-fetch.
• IncrementAgentNetworkConsumption's Create provides initial counter values (TokensInput: tokensIn, etc.) in the row, and on conflict the assignments add the same deltas to the existing values. The insert-vs-update arithmetic is consistent. Cross-check that no engine in use (sqlite, postgres, mysql) silently rejects the OnConflict clause — GORM emits engine-specific SQL but ON DUPLICATE KEY UPDATE (mysql) vs ON CONFLICT (...) (sqlite/postgres) need their unique constraint to match the composite PK on agent_network_consumption; it does, by construction.
• IncrementAgentNetworkConsumption writes updated_at: time.Now().UTC() literally inside the assignments map (sql_store_agentnetwork.go:333) — fine, but it's a Go-side timestamp captured at call time, not a DB-side now(). Acceptable for an audit field.
• GetAgentNetworkConsumption returns a zero-valued non-nil row on ErrRecordNotFound (sql_store_agentnetwork.go:364-371). Document or rename — a typed sentinel error would be more orthodox; callers must know not to error-check.

Concurrency / transactions

• Hot-path IncrementAgentNetworkConsumption runs outside any explicit transaction; concurrency safety relies entirely on the DB serialising the ON CONFLICT upsert against the composite PK. This is correct for postgres and mysql; for sqlite it serialises behind the single writer.
• SaveAgentNetworkSettings is a blind upsert with no version/etag — concurrent writes from two operators last-write-wins on the collection-toggle flags (settings.go:23-25). Acceptable for admin-curated state but worth flagging.
• Save*Provider uses db.Save on a struct with a PK already set — GORM emits UPDATE or INSERT based on row existence. No upsert clause is attached, so a race between two creates with the same generated xid (vanishingly unlikely) would surface as a PK violation.

Migration safety

• All six tables ride AutoMigrate (sql_store.go:141-142). AutoMigrate is additive: new columns get added, but it never drops columns nor narrows types. Three bool columns on agent_network_settings (EnableLogCollection, EnablePromptCollection, RedactPii) default to false at the GORM/DDL layer for existing rows; the test at sql_store_agentnetwork_budgetrule_test.go:83-112 locks that down on a fresh sqlite. Verify postgres/mysql produce the same default.
• The named index idx_agent_network_settings_cluster_subdomain on settings.go:15 is declared on only subdomain. Either the cluster column also needs gorm:"index:idx_agent_network_settings_cluster_subdomain" to make it composite, or the name is misleading.
• The named index idx_agent_network_provider on Provider.ProviderID (provider.go:30) is not unique and not scoped to account — two providers in the same account with the same provider_id are permitted at the DB layer; uniqueness, if any, must live above the store.

Backward compatibility

• Net additive. No removed methods, no renamed columns, no schema change to existing tables. Existing deployments running a prior binary continue to work; the first boot of the new binary creates the six tables.
• The Store interface grows by 23 methods (store.go:330-354); any non-mock external implementer of store.Store will fail to compile. The repo only has SqlStore + MockStore, both updated.

Performance (indexes, N+1)

• All by-account list queries hit the idx_account_id per-table index. No N+1: list methods return the full slice in one query.
• GetAgentNetworkSettingsByCluster (sql_store_agentnetwork.go:263-277) does a tablescan on cluster — no index. Tolerable for the bootstrap label generator (one-shot at provisioning) but worth noting if the call moves onto a hot path.
• ListAgentNetworkConsumption returns every row ever recorded for the account (sql_store_agentnetwork.go:382-400) — unbounded growth, no LIMIT, no time filter. With one row per (dim, window) per request burst, this table grows fastest of the six; a retention job + a paginated list method are obvious follow-ups.

Test coverage

Gap: there is no store-level test for providers (encryption round-trip), policies, guardrails, or IncrementAgentNetworkConsumption (concurrent upsert, window-key uniqueness). The consumption upsert is the most performance-sensitive method in this module and the only one without a real-sqlite test.

Known limitations / explicit non-goals

• No retention / GC for agent_network_consumption.
• No Delete for Settings (one row per account, cleared with the account).
• No DB-engine-specific tuning — the same struct tags drive sqlite, mysql, postgres.
• Provider extra_values and models are JSON blobs; querying inside them is not supported by design.
• GetAgentNetworkConsumption "not-found = zero row" contract is convenient but unconventional.

Cross-references

• Upstream: shared/api, management/agentnetwork
• End-to-end flow: ../01-end-to-end-flows.md
• Top-level: ../00-overview.md