diff --git a/docs/ai-coder/ai-gateway/cost-controls.md b/docs/ai-coder/ai-gateway/cost-controls.md
index 2af87b1edfb..52c4fa13c44 100644
--- a/docs/ai-coder/ai-gateway/cost-controls.md
+++ b/docs/ai-coder/ai-gateway/cost-controls.md
@@ -1,8 +1,307 @@
-# Cost Controls
+# AI Governance Cost Control
 
 > [!NOTE]
-> AI Gateway requires the [AI Governance Add-On](../ai-governance.md).
-> As of Coder v2.32, deployments without the add-on will not be able to
-> access AI Gateway.
+> AI Gateway is part of [AI Governance](../ai-governance.md), which is
+> included with a Premium license.
 
-<!-- TODO(AIGOV-476): Document AI Gateway cost controls. -->
+AI Governance Cost Control governs AI spend in two complementary ways:
+
+- **Enforcement** stops a user's requests routed via AI Gateway once their
+  spend reaches their budget.
+- **Reporting** shows what each user and group has approximately spent in the
+  current budget period.
+
+AI Governance Cost Control requires:
+
+- Coder v2.36 or later.
+- AI Gateway [enabled and configured](./setup.md) with at least one provider.
+
+> [!NOTE]
+> AI Governance Cost Control reports estimated spend rather than billed cost.
+> Estimates will not match your provider invoices exactly. For details, see
+> [How spend is estimated](#how-spend-is-estimated).
+
+These terms appear throughout this page and in the Coder dashboard:
+
+| Term                | What it means                                                                         | Where it is set                        |
+|---------------------|---------------------------------------------------------------------------------------|----------------------------------------|
+| **Budget period**   | The window spend accumulates in before it resets. Defaults to the UTC calendar month. | Deployment settings                    |
+| **Budget policy**   | The rule that selects a user's effective group. Defaults to the highest budget.       | Deployment settings                    |
+| **Group budget**    | A spend limit granted to each member of a group.                                      | **Groups** > {group} > **Settings**    |
+| **User override**   | A spend limit for one user that supersedes their group budget.                        | **Groups** > {group} > **Members** tab |
+| **Effective group** | The group that supplies a user's budget and has their spend associated with it.       | Resolved automatically                 |
+| **Estimated spend** | A user's approximate spend in the current budget period.                              | Estimated from usage                   |
+
+## Deployment settings
+
+Two deployment-wide settings govern budget resolution and the reset window. Each
+accepts a single value today.
+
+| Setting       | Flag                 | Environment variable     | Supported values | Default   |
+|---------------|----------------------|--------------------------|------------------|-----------|
+| Budget policy | `--ai-budget-policy` | `CODER_AI_BUDGET_POLICY` | `highest`        | `highest` |
+| Budget period | `--ai-budget-period` | `CODER_AI_BUDGET_PERIOD` | `month`          | `month`   |
+
+- **Budget policy** determines which budget wins when a user belongs to more
+  than one budgeted group. `highest` selects the largest.
+- **Budget period** sets the reset window. `month` is the UTC calendar month, so
+  spend resets at 00:00 UTC on the first day of each month.
+
+These settings are deployment-wide.
+
+## Budget
+
+**Every user's spend is recorded against a group.** A user only has a budget
+when one is set on a group they belong to, or when they are given a user
+override.
+
+> [!NOTE]
+> When AI Governance Cost Control is first deployed, users have **unlimited
+> spend** until an administrator sets budgets. Their spend is recorded against
+> the `Everyone` group.
+
+### Group budget
+
+Setting a group budget requires the Owner, User Admin, Organization Admin, or
+Organization User Admin [role](../../admin/users/groups-roles.md).
+
+A group budget applies to each member individually rather than to the group as a
+whole. For example, if a group has ten members and a budget of $200 USD, each
+member can spend $200 USD and the group has a total spend limit of $2,000 USD.
+
+1. Go to **Groups** and select a group.
+1. Select **Settings**.
+1. Under **AI budget**, set **Monthly limit per member**.
+1. Select **Save**.
+
+![Group AI budget settings](../../images/aibridge/group-ai-budget.png)
+
+Budget values behave as follows:
+
+- An empty field means no limit. The field displays `unlimited`.
+- `$0 USD` blocks every request routed via AI Gateway from members whose
+  effective group is this group.
+- The maximum is `$1,000,000 USD` per member per budget period.
+
+Note: Members who belong to other groups with budgets are still governed by
+whichever group the budget policy selects. See
+[Effective group resolution](#effective-group-resolution).
+
+### User override
+
+Adding or removing an override requires the Owner or User Admin
+[role](../../admin/users/groups-roles.md). Other administrator roles can view
+overrides but cannot change them.
+
+Override a group budget when one user needs a different limit from the rest of
+their group.
+
+1. Go to **Groups**, select a group, then open the **Members** tab.
+1. Find the member to apply the override to, open their action menu, and select
+   **Manage AI budget**.
+1. Enable **Override group budget**.
+1. Set **Custom monthly budget**, then choose the group in
+   **Budget assigned to**.
+1. Select **Update**.
+
+![User AI budget override](../../images/aibridge/user-override-ai-budget.png)
+
+Overrides behave as follows:
+
+- A user can have only one override at a time.
+- An override supersedes every group budget the user belongs to.
+- Spend is always attributed to a group, so an override must name the assigned
+  group. This group can be different from the group selected in the **Members**
+  tab. The user must belong to the assigned group.
+- The `$0 USD` to `$1,000,000 USD` range applies to overrides as well.
+- Disabling **Override group budget** removes the override and returns the user
+  to the budget of their [effective group](#effective-group-resolution).
+
+### Effective group resolution
+
+A user can belong to several groups that have budgets, and can also hold an
+override. AI Gateway resolves a single effective group for each request, in this
+order:
+
+1. The user's [override](#user-override) takes precedence over every group
+   budget.
+1. Otherwise, the [budget policy](#deployment-settings) selects one of the
+   groups the user belongs to. The default policy, `highest`, selects the group
+   with the largest budget.
+1. If none of those groups has a budget, the user has *effectively* unlimited
+   spend and their spend is recorded against the `Everyone` group.
+
+> [!NOTE]
+> Groups with identical budgets are ranked by the organization membership the
+> user joined first, then by group ID. To see the effective group currently
+> assigned to a user, see [Monitor spend](#monitor-spend). The effective group is
+> deployment-wide, so it can be a group in a different organization.
+
+Recorded spend is immutable. Changing which budget applies to a user affects
+future requests only: spend that Coder has already recorded stays with the group
+it was attributed to, so a user's history can span several groups. The effective
+group is resolved at request time, so changing a group budget can change which
+group applies to a user on future requests.
+
+## How enforcement works
+
+AI Gateway checks each request before forwarding it upstream. The check compares
+the user's spend in the current budget period with the budget that applies to the
+request:
+
+- Spend below the budget: the request proceeds.
+- Spend at or above the budget: AI Gateway returns `403 Forbidden` with a
+  message that describes the issue.
+
+Users without a budget have **unlimited spend**, so their requests proceed
+without enforcement. A blocked user's access resumes when the budget period
+resets, when an administrator raises the budget, or when an override is added.
+
+> [!NOTE]
+> Enforcement is approximate. A request's cost is known only after the provider
+> response reaches AI Gateway, so concurrent in-flight requests can carry a user
+> slightly past their budget. Subsequent requests are blocked after the recorded
+> spend reaches the budget.
+
+### Notifications
+
+The first time a user's spend crosses a threshold within a budget period, Coder
+notifies the user and deployment-wide Owners and User Admins, excluding the
+affected user:
+
+| Threshold | User notification              | Admin notification                       |
+|-----------|--------------------------------|------------------------------------------|
+| 85%       | You're approaching your budget | `<username>` is approaching their budget |
+| 100%      | You've reached your budget     | `<username>` has reached their budget    |
+
+- A single expensive request can cross both thresholds at once.
+- Budgets of `$0 USD` and unpriced usage cross no thresholds.
+- Notifications are informational. Enforcement does not depend on them.
+
+For delivery methods, see
+[Notifications](../../admin/monitoring/notifications/index.md).
+
+## How spend is estimated
+
+Coder multiplies the token usage of each request by the published price of the
+model that served it. Prices come from a curated [models.dev](https://models.dev)
+snapshot that ships with every Coder release, so no configuration is required.
+
+Spend accumulates only from the moment v2.36 is deployed. Upgrading mid-month
+therefore produces a partial first period.
+
+To see which models are priced in the release version you run, consult the
+price book for your Coder version:
+
+```text
+https://github.com/coder/coder/blob/release/<VERSION>/coderd/aibridge/prices/data/prices.json
+```
+
+Replace `<VERSION>` with your Coder minor version, for example `2.36`.
+
+> [!IMPORTANT]
+> Estimated spend can differ from provider-reported amounts, and some usage might
+> not count toward spend:
+>
+> - Estimates exclude negotiated discounts, committed-use pricing, and
+>   provider-specific billing rules.
+> - Requests to models that are missing from the price table record token usage
+>   but add nothing to a user's spend. A user who only calls unpriced models is
+>   effectively unlimited.
+
+Monitor `coder_ai_gateway_cost_control_unpriced_token_usage_records_total`,
+labeled by `provider` and `model`, to detect unpriced usage. Any non-zero value
+means spend is under-counted. Because the price book ships with the release, a
+newly launched model can remain unpriced until you upgrade Coder.
+
+## Monitor spend
+
+Spend reporting is available in the Coder dashboard and as a CSV export.
+Prometheus metrics report enforcement and pricing gaps.
+
+### Dashboard
+
+Visibility follows the viewer's role:
+
+| Who                                                  | Sees                                                                 |
+|------------------------------------------------------|----------------------------------------------------------------------|
+| Every user                                           | Their own spend and budget, or unlimited state, in their avatar menu |
+| Members of a group                                   | The group's spend and budget, and their own member row               |
+| Owners, User Admins, and organization administrators | Spend and budgets for every group and every member                   |
+
+- The **Groups** page compares each group's spend with the combined limits of
+  the members it covers.
+- The **Members** tab of a group reports each member's spend, their budget, and
+  its source, labeled `Custom limit` for an override or `Group limit` for a
+  group budget. If the effective group is another group in the same organization,
+  the row shows `Budget managed by another group`. If the effective group is in a
+  different organization, the row shows a dash and explains that the group is not
+  visible there.
+- The avatar menu reports the signed-in user's own spend for the budget period
+  as `$<spend> / $<budget> USD`, or `$<spend> / Unlimited USD` when no budget
+  applies.
+
+Administrators can also use the
+[Get user AI spend](../../reference/api/enterprise.md#get-user-ai-spend) API
+endpoint to see a user's current effective group.
+
+### CSV Export
+
+Users who can read group-member data for the organization can export estimated
+spend for reporting and internal cost allocation. The export is available through
+the API only.
+
+```sh
+curl -H "Coder-Session-Token: $CODER_SESSION_TOKEN" \
+  "https://coder.example.com/api/v2/organizations/<organization>/ai/spend/export"
+```
+
+- Without parameters, the export covers the current budget period.
+- To select a range, pass `period_start` and `period_end` together as RFC 3339
+  timestamps. A range can span at most 31 days.
+- Each row breaks spend down by user, group, model, and provider, with the
+  underlying token counts.
+
+### Prometheus Metrics
+
+Prometheus metrics report blocked requests, users over budget, unpriced usage,
+and enforcement latency. For the full metric list, including types and labels,
+see [Prometheus metrics](../../admin/integrations/prometheus.md).
+
+## Migrate from Coder Agents Cost Control
+
+In v2.36, AI Governance Cost Control replaces Coder Agents Cost Control. The
+legacy Coder Agents Spend page remains available until v2.37.
+
+> [!WARNING]
+> Spend limits configured under **Admin settings** > **AI** > **Spend** are no
+> longer enforced by Coder Agents. To enforce spend, set an AI Governance budget.
+
+To migrate existing limits:
+
+1. Record the limits currently set under **Admin settings** > **AI** >
+   **Spend**, including the default limit and any group or user overrides.
+1. Recreate group limits as [group budgets](#group-budget).
+1. Recreate per-user limits as [user overrides](#user-override).
+
+Expect the following differences:
+
+- No deployment-wide default exists. Each group that needs a limit requires its
+  own budget.
+- The UTC calendar month is the only period. Daily and weekly periods are not
+  currently supported.
+- Users in several budgeted groups receive the highest budget. Coder Agents Cost
+  Control applied the lowest.
+- Budgets cover priced AI Gateway traffic. Chat, IDE extensions, and CLI agents
+  draw on the same budget when their provider and model are priced. See
+  [How spend is estimated](#how-spend-is-estimated).
+- Recorded spend does not carry over. Every user starts the first period at
+  $0 USD.
+- Coder Agents users who exceed their budget see a usage limit error in chat.
+  The error details include the AI Governance budget limit.
+
+## Next steps
+
+- [Monitoring](./monitoring.md)
+- [Auditing AI sessions](./audit.md)
+- [AI Gateway API reference](../../reference/api/enterprise.md)
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diff --git a/docs/manifest.json b/docs/manifest.json
index 56e75d4cd29..2b9708fb840 100644
--- a/docs/manifest.json
+++ b/docs/manifest.json
@@ -1330,10 +1330,10 @@
 									"state": ["premium"]
 								},
 								{
-									"title": "Cost Controls",
-									"description": "Manage AI Gateway spend with budgets, spend limits, and budget notifications.",
+									"title": "AI Governance Cost Control",
+									"description": "Configure AI Gateway budgets, enforcement, notifications, and spend reporting.",
 									"path": "./ai-coder/ai-gateway/cost-controls.md",
-									"state": ["ai governance add-on"]
+									"state": ["premium"]
 								},
 								{
 									"title": "Reference",