Guards

Author Filters — content-inspection Guards — and bind them to model or MCP server (tool) connections. Text Filters attach to model connections; JSON Filters attach to tool connections. All Guards tools require workspace context. Editing a Filter deploys a new active version. Assigned connections pick it up on the next gateway sync — history is preserved and can be rolled back to. A Filter whose stored config fails to decode blocks its (connection, direction) until the config is fixed — the gateway never relays unfiltered traffic.

List filters

dome_guards_list_filters List the workspace’s Filters, each with its active version and config.

Parameter	Type	Required	Description
—	—	—	No parameters

Get filter

dome_guards_get_filter Fetch one Filter’s active version and config.

Parameter	Type	Required	Description
`filter`	string	Yes	Filter name or UUID

List filter versions

dome_guards_list_filter_versions List a Filter’s version history, newest first. Rollback-produced versions cite their source version id.

Parameter	Type	Required	Description
`filter`	string	Yes	Filter name or UUID

Create filter

dome_guards_create_filter Create a Filter — its first active version. Supply the config via the convenience params (text-only) or config_json (any kind).

Parameter	Type	Required	Description
`name`	string	Yes	Filter name (workspace-scoped)
`description`	string	No	One-line description
`redact_substrings`	array of string	No	Substrings to redact in matched responses (text)
`block_substrings`	array of string	No	Substrings that block the response on a match (text)
`redact_ssn`	bool	No	Redact US SSN patterns (text)
`block_ssn`	bool	No	Block the response on an SSN match (text)
`config_json`	string	For JSON Filters, or full-fidelity text	Protojson `dome.guards.v1.FilterConfig`. Overrides the convenience params.

The convenience params build at most two components — a redact component and a block component, redact ordered first — and only produce text Filters. Pass config_json to author a JSON Filter or a multi-component text chain.

JSON Filter config

{
  "json": {
    "components": [
      {
        "field_actions": [
          { "matcher": { "key": "ssn" },   "action": "FILTER_ACTION_OMIT" },
          { "matcher": { "key": "email" }, "action": "FILTER_ACTION_REDACT" },
          { "matcher": { "key": "card" },  "action": "FILTER_ACTION_BLOCK" }
        ]
      }
    ]
  }
}

BLOCK withholds the whole message. OMIT removes the key and value. REDACT rewrites the value with a redaction sentinel. When multiple actions target the same key: BLOCK > OMIT > REDACT.

Update filter

dome_guards_update_filter Edit metadata in place (new_name, description), or deploy a new active version by passing any config param. History is preserved.

Parameter	Type	Required	Description
`filter`	string	Yes	Filter name or UUID
`new_name`	string	No	New name for the logical Filter
`description`	string	No	New description
`redact_substrings` / `block_substrings` / `redact_ssn` / `block_ssn` / `config_json`	—	No	Any config param deploys a new active version

Pass at least one of new_name, description, or a config param.

Rollback filter

dome_guards_rollback_filter Roll a Filter back to an earlier version. The target version’s config is copied forward into a new active version.

Parameter	Type	Required	Description
`filter`	string	Yes	Filter name or UUID
`to_version`	number	Yes	Version number to roll back to

Delete filter

dome_guards_delete_filter Hard-delete a Filter and its connection assignments.

Parameter	Type	Required	Description
`filter`	string	Yes	Filter name or UUID

List model connection filters

dome_model_guards_filters_list List the text Filters assigned to a model connection, in chain order, grouped by direction.

Parameter	Type	Required	Description
`connection`	string	Yes	Model connection name

Set model connection filters

dome_model_guards_filters_set Replace the entire ordered Filter chain for one direction on a model connection. Only text-kind Filters may be assigned. response filters completions the agent receives. request filters the outbound prompt before dispatch to the model provider — a match can redact or block the call.

Parameter	Type	Required	Description
`connection`	string	Yes	Model connection name
`direction`	string	Yes	`response` or `request`
`filters`	array of string	Yes	Ordered Filter names or UUIDs; empty clears the chain

List tool connection filters

dome_tool_guards_filters_list List the JSON Filters assigned to an MCP server (tool) connection, in chain order, grouped by direction.

Parameter	Type	Required	Description
`connection`	string	Yes	MCP server connection name

Set tool connection filters

dome_tool_guards_filters_set Replace the entire ordered Filter chain for one direction on a tool connection. Only json-kind Filters may be assigned. request filters run over tool arguments before the call reaches the upstream MCP server — matched fields are redacted or omitted, or the whole call is blocked. response filters run over the tool result before the agent sees it.

Parameter	Type	Required	Description
`connection`	string	Yes	MCP server connection name
`direction`	string	Yes	`response` or `request`
`filters`	array of string	Yes	Ordered Filter names or UUIDs; empty clears the chain

Next steps

Create and assign Filters from Govern. Catalogs cover windows and path syntax:

Configure Guards
Guards concept
Guards reference

Overview

Tools

List filters

Get filter

List filter versions

Create filter

JSON Filter config

Update filter

Rollback filter

Delete filter

List model connection filters

Set model connection filters

List tool connection filters

Set tool connection filters

Next steps

​List filters

​Get filter

​List filter versions

​Create filter

​JSON Filter config

​Update filter

​Rollback filter

​Delete filter

​List model connection filters

​Set model connection filters

​List tool connection filters

​Set tool connection filters

​Next steps

List filters

Get filter

List filter versions

Create filter

JSON Filter config

Update filter

Rollback filter

Delete filter

List model connection filters

Set model connection filters

List tool connection filters

Set tool connection filters

Next steps