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title Policy Schema Reference
sidebar-title Policy Schema
description Complete field reference for the sandbox policy YAML including static and dynamic sections.
keywords Generative AI, Cybersecurity, Policy, Schema, YAML, Reference, Security
position 3

Complete field reference for the sandbox policy YAML. Each field is documented with its type, whether it is required, and whether it is static (locked at sandbox creation) or dynamic (hot-reloadable on a running sandbox).

Top-Level Structure

A policy YAML file contains the following top-level fields:

version: 1
filesystem_policy: { ... }
landlock: { ... }
process: { ... }
network_policies: { ... }
Field Type Required Category Description
version integer Yes -- Policy schema version. Must be 1.
filesystem_policy object No Static Controls which directories the agent can read and write.
landlock object No Static Configures Landlock LSM enforcement behavior.
process object No Static Sets the user and group the agent process runs as.
network_policies map No Dynamic Declares which binaries can reach which network endpoints.

Static fields are set at sandbox creation time. Changing them requires destroying and recreating the sandbox. Dynamic fields can be updated on a running sandbox with openshell policy update for incremental merges or openshell policy set for full replacement, and take effect without restarting.

Version

The version field identifies which schema the policy uses:

Field Type Required Description
version integer Yes Schema version number. Currently must be 1.

Filesystem Policy

Category: Static

Controls filesystem access inside the sandbox. Paths not listed in either read_only or read_write are inaccessible.

Field Type Required Description
include_workdir bool No When true, automatically adds the agent's working directory to read_write.
read_only list of strings No Paths the agent can read but not modify. Typically system directories like /usr, /lib, /etc.
read_write list of strings No Paths the agent can read and write. Typically /sandbox (working directory) and /tmp.

Validation constraints:

  • Every path must be absolute (start with /).
  • Paths must not contain .. traversal components. The server normalizes paths before storage, but rejects policies where traversal would escape the intended scope.
  • Read-write paths must not be overly broad (for example, / alone is rejected).
  • Each individual path must not exceed 4096 characters.
  • The combined total of read_only and read_write paths must not exceed 256.

Policies that violate these constraints are rejected with INVALID_ARGUMENT at creation or update time. Disk-loaded YAML policies that fail validation fall back to a restrictive default.

Example:

filesystem_policy:
  include_workdir: true
  read_only:
    - /usr
    - /lib
    - /proc
    - /dev/urandom
    - /etc
  read_write:
    - /sandbox
    - /tmp
    - /dev/null

Landlock

Category: Static

Configures Landlock LSM enforcement at the kernel level. Landlock provides mandatory filesystem access control below what UNIX permissions allow.

Field Type Required Values Description
compatibility string No best_effort, hard_requirement How OpenShell handles Landlock failures. Refer to the behavior table below.

Compatibility modes:

Value Kernel ABI unavailable Individual path inaccessible All paths inaccessible
best_effort Warns and continues without Landlock. Skips the path, applies remaining rules. Warns and continues without Landlock (refuses to apply an empty ruleset).
hard_requirement Aborts sandbox startup. Aborts sandbox startup. Aborts sandbox startup.

best_effort (the default) is appropriate for most deployments. It handles missing paths gracefully. For example, /app might not exist in every container image but is included in the baseline path set for containers that do have it. Individual missing paths are skipped while the remaining filesystem rules are still enforced.

hard_requirement is for environments where any gap in filesystem isolation is unacceptable. If a listed path cannot be opened for any reason (missing, permission denied, symlink loop), sandbox startup fails immediately rather than running with reduced protection.

When a path is skipped under best_effort, the sandbox logs a warning that includes the path, the specific error, and a human-readable reason (for example, "path does not exist" or "permission denied").

Example:

landlock:
  compatibility: best_effort

Process

Category: Static

Sets the OS-level identity for the agent process inside the sandbox.

Field Type Required Description
run_as_user string No The user name or UID the agent process runs as. Default: sandbox.
run_as_group string No The group name or GID the agent process runs as. Default: sandbox.

Validation constraint: Neither run_as_user nor run_as_group can be set to root or 0. Policies that request root process identity are rejected at creation or update time.

Example:

process:
  run_as_user: sandbox
  run_as_group: sandbox

Network Policies

Category: Dynamic

A map of named network policy entries. Each entry declares a set of endpoints and a set of binaries. Only the listed binaries are permitted to connect to the listed endpoints. The map key is a logical identifier. The name field inside the entry is the display name used in logs.

Network Policy Entry

Each entry in the network_policies map has the following fields:

Field Type Required Description
name string No Display name for the policy entry. Used in log output. Defaults to the map key.
endpoints list of endpoint objects Yes Hosts and ports this entry permits.
binaries list of binary objects Yes Executables allowed to connect to these endpoints.

Endpoint Object

Each endpoint defines a reachable destination and optional inspection rules.

Field Type Required Description
host string Yes Hostname or IP address. Supports a * wildcard inside the first DNS label only: *.example.com, **.example.com, and intra-label patterns like *-aiplatform.googleapis.com are accepted; bare */**, TLD wildcards (*.com), and wildcards outside the first label are rejected at load time.
port integer Yes TCP port number.
path string No Optional HTTP path glob used to select between L7 endpoints that share the same host and port. Empty means all paths. Use this when REST and GraphQL live under the same host, such as /repos/** and /graphql.
protocol string No Set to rest for HTTP method/path inspection, websocket for RFC 6455 upgrade and client text-message inspection, or graphql for GraphQL-over-HTTP operation inspection. WebSocket endpoints can also use GraphQL operation rules for GraphQL-over-WebSocket traffic. Omit for TCP passthrough.
tls string No TLS handling mode. The proxy auto-detects TLS by peeking the first bytes of each connection and terminates it for inspected HTTPS traffic, so this field is optional in most cases. Set to skip to disable auto-detection for edge cases such as client-certificate mTLS or non-standard protocols. The values terminate and passthrough are deprecated and log a warning; they are still accepted for backward compatibility but have no effect on behavior.
enforcement string No enforce actively blocks disallowed requests. audit logs violations but allows traffic through.
access string No Access preset. One of read-only, read-write, or full. Mutually exclusive with rules.
rules list of rule objects No Fine-grained protocol-specific allow rules. Mutually exclusive with access.
deny_rules list of deny rule objects No L7 deny rules that block specific requests even when allowed by access or rules. Deny rules take precedence over allow rules.
allowed_ips list of string No CIDR or IP allowlist for SSRF override. Exact user-declared hostname endpoints may resolve to RFC 1918 private addresses without this field, but wildcard, hostless, and policy-advisor-proposed endpoints still require allowed_ips for private resolved IPs. Entries overlapping loopback (127.0.0.0/8), link-local (169.254.0.0/16), or unspecified (0.0.0.0) are rejected at load time.
allow_encoded_slash bool No When true, L7 request parsing preserves %2F inside path segments instead of rejecting it. Use this for registries and APIs such as npm scoped packages (/@scope%2Fname). Defaults to false.
websocket_credential_rewrite bool No When true on a protocol: rest or protocol: websocket endpoint, OpenShell rewrites credential placeholders in client-to-server WebSocket text messages after an allowed HTTP 101 upgrade. Binary frames are relayed but not rewritten. Defaults to false.
request_body_credential_rewrite bool No When true on a protocol: rest endpoint, OpenShell rewrites credential placeholders in UTF-8 application/json, application/x-www-form-urlencoded, and text/* request bodies before forwarding upstream. The proxy buffers at most 256 KiB and updates Content-Length after rewriting. Defaults to false.
persisted_queries string No GraphQL hash-only behavior for protocol: graphql and GraphQL-over-WebSocket operation policy. Default is deny; use allow_registered only with graphql_persisted_queries.
graphql_persisted_queries map No Trusted GraphQL persisted-query registry keyed by hash or saved-query ID. Values contain operation_type, optional operation_name, and optional root fields.
graphql_max_body_bytes integer No Maximum GraphQL-over-HTTP request body bytes buffered for inspection. Defaults to 65536.

Credential rewrite recognizes the canonical openshell:resolve:env:KEY placeholder form and whole-token provider-shaped aliases such as provider-OPENSHELL-RESOLVE-ENV-API_TOKEN when the referenced environment key exists in the configured provider credentials.

Access Levels

The access field accepts one of the following values:

Value REST expansion WebSocket expansion GraphQL expansion
full All methods and paths. WebSocket upgrade and all inspected client text-message paths. All operation types.
read-only GET, HEAD, OPTIONS. WebSocket upgrade handshake only. query operations.
read-write GET, HEAD, OPTIONS, POST, PUT, PATCH. WebSocket upgrade handshake and client text messages. query and mutation operations.

Allow Rule Objects

Used when access is not set. Each entry in rules contains an allow object. The tables below list the fields inside that allow object.

REST Allow Rule (protocol: rest)

REST allow rules match HTTP requests by method, path, and optional query parameters.

Field Type Required Description
method string Yes HTTP method to allow (for example, GET, POST). * matches any method.
path string Yes URL path pattern. Supports * and ** glob syntax.
query map No Query parameter matchers keyed by decoded param name. Matcher value can be a glob string (tag: "foo-*") or an object with any (tag: { any: ["foo-*", "bar-*"] }).

Example REST allow rules:

rules:
  - allow:
      method: GET
      path: /**/info/refs*
      query:
        service: "git-*"
  - allow:
      method: POST
      path: /**/git-upload-pack
      query:
        tag:
          any: ["v1.*", "v2.*"]
WebSocket Allow Rule (protocol: websocket)

WebSocket allow rules match the RFC 6455 HTTP upgrade by path and match client-to-server text messages on the same upgraded connection with the synthetic WEBSOCKET_TEXT method. Binary frames are relayed but are not rewritten.

Field Type Required Description
method string Yes GET allows the upgrade handshake, WEBSOCKET_TEXT allows client text messages after upgrade, and * matches both inspected actions.
path string Yes URL path pattern from the original upgrade request. Supports * and ** glob syntax.
query map No Query parameter matchers from the original upgrade request. Matcher syntax is the same as REST allow rules.

Example WebSocket allow rules:

rules:
  - allow:
      method: GET
      path: /v1/realtime/**
  - allow:
      method: WEBSOCKET_TEXT
      path: /v1/realtime/**
GraphQL Allow Rule (protocol: graphql or GraphQL-over-WebSocket)

GraphQL allow rules match parsed GraphQL operations by operation type, optional operation name, and optional root fields. On protocol: graphql, they apply to GraphQL-over-HTTP GET and POST requests. On protocol: websocket, include a separate GET allow rule for the RFC 6455 upgrade, then use GraphQL allow rules for client operation messages using the graphql-transport-ws subscribe message type or the legacy graphql-ws start message type.

Field Type Required Description
operation_type string Yes GraphQL operation type: query, mutation, subscription, or *.
operation_name string No GraphQL operation-name glob. Omit to match any operation name.
fields list of string No GraphQL root-field globs. Every selected root field must match one configured glob. Omit to match all root fields.

Example GraphQL allow rules:

rules:
  - allow:
      operation_type: query
      fields: [viewer, repository]
  - allow:
      operation_type: mutation
      operation_name: Issue*
      fields: [createIssue]

Example GraphQL-over-WebSocket allow rules:

rules:
  - allow:
      method: GET
      path: /graphql
  - allow:
      operation_type: subscription
      fields: [messageAdded]
  - allow:
      operation_type: query
      fields: [viewer]

Do not combine method, path, or query with operation_type, operation_name, or fields inside the same WebSocket rule. When a WebSocket endpoint has GraphQL operation policy, use GraphQL rules for client messages instead of a raw WEBSOCKET_TEXT allow rule.

Deny Rule Objects

Blocks specific operations on endpoints that otherwise have broad access. Deny rules are evaluated after allow rules and take precedence: if a request matches any deny rule, it is blocked regardless of what the allow rules or access preset permit.

REST Deny Rule (protocol: rest)

REST deny rules use the same field names as REST allow rules, but they appear directly under each deny_rules entry instead of under an allow wrapper.

Field Type Required Description
method string Yes HTTP method to deny (for example, POST, DELETE). * matches any method.
path string Yes URL path pattern. Same glob syntax as allow rules. Use ** to match any path.
query map No Query parameter matchers. Same syntax as allow rule query.

Example REST deny rules:

endpoints:
  - host: api.github.com
    port: 443
    protocol: rest
    enforcement: enforce
    access: read-write
    deny_rules:
      - method: POST
        path: "/repos/*/pulls/*/reviews"
      - method: PUT
        path: "/repos/*/branches/*/protection"
      - method: "*"
        path: "/repos/*/rulesets"
WebSocket Deny Rule (protocol: websocket)

WebSocket deny rules use the same field names as WebSocket allow rules, but they appear directly under each deny_rules entry instead of under an allow wrapper.

Field Type Required Description
method string Yes GET denies matching upgrade handshakes, WEBSOCKET_TEXT denies matching client text messages after upgrade, and * matches both inspected actions.
path string Yes URL path pattern from the original upgrade request. Same glob syntax as allow rules.
query map No Query parameter matchers from the original upgrade request. Same syntax as allow rule query.

Example WebSocket deny rules:

endpoints:
  - host: realtime.example.com
    port: 443
    protocol: websocket
    enforcement: enforce
    access: read-write
    deny_rules:
      - method: WEBSOCKET_TEXT
        path: "/v1/admin/**"
GraphQL Deny Rule (protocol: graphql or GraphQL-over-WebSocket)

GraphQL deny rules use the same field names as GraphQL allow rules, but they appear directly under each deny_rules entry instead of under an allow wrapper. On WebSocket GraphQL endpoints, they apply only to classified GraphQL operation messages; protocol lifecycle messages such as connection_init, ping, pong, and complete are allowed as WebSocket control-plane messages and are not payload-logged.

Field Type Required Description
operation_type string Yes GraphQL operation type to deny: query, mutation, subscription, or *.
operation_name string No GraphQL operation-name glob.
fields list of string No GraphQL root-field globs. Any matching root field blocks the request. Omit to deny every operation that matches operation_type and operation_name.

Example GraphQL deny rules:

endpoints:
  - host: api.github.com
    port: 443
    protocol: graphql
    enforcement: enforce
    access: read-write
    deny_rules:
      - operation_type: mutation
        fields: [deleteRepository]
      - operation_type: mutation
        operation_name: Admin*

Binary Object

Identifies an executable that is permitted to use the associated endpoints.

Field Type Required Description
path string Yes Filesystem path to the executable. Supports glob patterns with * and **. For example, /sandbox/.vscode-server/** matches any executable under that directory tree.

Full Example

The following policy grants read-only GitHub API access and npm registry access:

network_policies:
  github_rest_api:
    name: github-rest-api
    endpoints:
      - host: api.github.com
        port: 443
        protocol: rest
        enforcement: enforce
        access: read-only
    binaries:
      - path: /usr/local/bin/claude
      - path: /usr/bin/node
      - path: /usr/bin/gh
  npm_registry:
    name: npm-registry
    endpoints:
      - host: registry.npmjs.org
        port: 443
        protocol: rest
        access: read-only
        allow_encoded_slash: true
    binaries:
      - path: /usr/bin/npm
      - path: /usr/bin/node