Builtin Policies
Omnigent ships with policies for common guardrails, organized into two categories:
Safety and Cost Control. Your Omnigent can apply any of
these by name when you ask it to add a policy, or you
can reference them in YAML by their full path in the handler field.
All builtin policies live under omnigent.policies.builtins.
Safety
| Policy | What it does | Parameters |
|---|---|---|
ask_on_os_tools | ASKs before any file or shell operation. | None |
block_skills | Prevents specific skills from loading. | blocked (string[], required) |
block_working_dir_changes | Blocks shell commands that change the working directory. | block_cd (bool), block_worktree (bool), allowed_dirs (string[]), action ("deny" or "ask") |
cel_policy | Write custom policy logic using CEL (Common Expression Language), a safe, non-Turing-complete expression language. The expression returns a map with result ("DENY", "ASK", or "ALLOW") plus optional reason and state_updates keys — see Custom Policies. | expression (CEL expression string), reason (fallback deny/ask message) |
deny_pii_in_llm_request | Scans outgoing messages for PII and blocks or flags them. | pii_types (string[]), action ("DENY" or "ASK") |
detect_thrashing | Detects when an agent is failing repeatedly by tracking tool-result outcomes in a rolling window. Fires when consecutive errors cross a threshold or the window error rate is too high. Error detection is heuristic — no server LLM required. | consecutive_threshold (int, default 5; 0 disables), window (int, default 10), window_error_rate (number 0.0–1.0, default 0.8; 0 disables), action ("ASK" or "DENY", default "ASK") |
detect_loop | ASKs when the agent is stuck retrying the same tool call. Hashes each (tool, arguments) pair and, when an identical call repeats threshold times within a sliding window of recent calls, routes it to human approval. Catches a token-waste pattern max_tool_calls_per_session can't see, since that policy only counts total calls. | window (int, default 10, min 1), threshold (int, default 3, min 1) |
enforce_sandbox | Forces a sandbox configuration on agent start. | sandbox_type, allow_network, write_paths, read_paths |
gcalendar_policy | Controls Google Calendar. Defaults to read-only. | None |
gdrive_policy | Controls Google Drive, Docs, Sheets, and Slides access. Writes restricted to agent-created files by default. Optionally enforces Bell-LaPadula "no write-down": once the session reads a confidential file, its writes are confined to that set. | read_all, allow_create, write_files, read_files, comment_files, confidential_files (string[]), write_down_action ("DENY" or "ASK", default "DENY") |
github_policy | Controls GitHub read/write access across MCP tools and shell commands. Irreversible destructive operations (deletes) are denied by default even on allowed repos, unless allow_destructive is set. git push force flags (--force, -f, --force-with-lease, --force-if-includes), bundled short flags containing f (e.g. -uf), and +refspec force prefixes are denied by default regardless of the repo/branch allowlists, unless deny_force_push is set to false. | read_all, write_repos, write_branches, allow_destructive (bool, default false), deny_force_push (bool, default true) |
gmail_policy | Controls Gmail. Defaults to read + draft, no send. | allow_read, allow_send, allow_drafts |
intent_based_authorization | Records the first user message as the session's intent, then ASKs before any tool call that has no plausible connection to that intent. Requires an llm: config block; fails open when none is available. | None |
max_tool_calls_per_session | DENYs after a total tool-call limit is reached. | limit (int, default 100) |
prompt_policy | Evaluate policy decisions using an LLM. The policy sends the event context to a model and interprets the response as ALLOW/ASK/DENY. Useful for nuanced decisions that can't be expressed as static rules. | prompt (system instructions for the evaluator model) |
risk_score_policy | Accumulate a risk score from tool calls and sensitive data labels. Escalates guarded tools to ASK or DENY once the score exceeds a threshold. | threshold (int), tool_points (object mapping tool names to points), sensitive_labels (object mapping labels to points), guarded_tools (string[]), escalate_action ("ASK" or "DENY") |
blast_radius | Classifies shell commands as safe (ALLOW), recoverable-but-risky (risky_action), or catastrophic (always DENY, e.g. rm -rf / or force-push). Covers the shell tool across Omnigent (sys_os_shell), Claude/Codex (Bash), Cursor, Pi, Hermes, and Goose. | gate_pushes (bool, default true), risky_action ("ASK" default or "DENY"), deny_reason |
spawn_bounds | Limits the number of sub-agent dispatches per turn to prevent runaway fan-out. | max_dispatches_per_turn (int, default 5), dispatch_tools |
headless_subagent_purpose_guard | Requires every sub-agent dispatch to declare a purpose (implement, review, explore, search). | allowed_purposes (string[]), deny_reason |
worktree_guard | Blocks file writes outside the worker's git worktree to prevent cross-branch contamination. | allowed_root (string, default .worktrees), deny_reason |
read_only_os | Denies every file-mutating tool so a report-only agent can read and run shell but never change code. | deny_reason |
Cost Control
| Policy | What it does | Parameters |
|---|---|---|
cost_budget | Tracks cumulative LLM spend per session. ASKs at soft thresholds, blocks expensive models at the hard limit. | max_cost_usd (required), ask_thresholds_usd, expensive_models |
detect_task_switch | Uses the server-level LLM to detect when a user starts a new unrelated task and nudges starting a fresh session. | min_turns (int), history_window (int), action ("ASK" or "DENY", default "ASK"), classification_prompt (string) |
deny_trivial_to_expensive_model | Classifies messages as trivial or complex. Routes trivial tasks away from expensive models. | expensive_models (string[], required), classification_prompt (string) |
subagent_cost_budget | Gates a sub-agent on its own subtree LLM spend. Blocks expensive models at the hard limit, ASKs at soft thresholds. Attach to a child via sys_session_send's cost_budget argument. | max_cost_usd, ask_thresholds_usd, expensive_models |
user_daily_cost_budget | Same as cost_budget, but enforced per-user daily across all sessions. | max_cost_usd (required), ask_thresholds_usd, expensive_models |
Usage examples
Confine confidential Google Drive data
gdrive_policy can layer Bell-LaPadula's classic "no write-down" rule on top
of its access controls. You declare a set of confidential documents up front
with confidential_files (file IDs or Google URLs). The rule engages only once
the session reads one of those files: from then on, its writes are confined
to the confidential set. A write to — or creation of — any other file would move
confidential data into a less-protected place, so it is blocked.
# Omnigent config (policies block)
policies:
confidential_containment:
type: function
handler: omnigent.policies.builtins.google.gdrive_policy
factory_params:
# The confidential compartment: file IDs or Google URLs.
confidential_files:
- "1ConfidentialStrategyDocID"
# Allow creating new files, so a create can be shown being gated as a
# write-down rather than blocked outright by the base access rules.
allow_create: true
# DENY (hard block) or ASK (require human approval) on a write-down.
write_down_action: DENYBecause the confidential set is declared explicitly rather than inferred from a per-document classification label, the rule works on any Google Drive tenant.
Catch a stuck agent
detect_thrashing watches tool_result events and flags an agent that is
failing repeatedly — retrying the same broken command, looping on a permission
error, or otherwise making no progress. Unlike detect_task_switch,
it needs no server LLM: error detection is heuristic (common error prefixes
like Error:, Traceback (most recent call last), Permission denied, and
JSON payloads carrying an "error" key).
It keeps a rolling window of recent tool-result outcomes (error or success) in session state and fires when either condition is met:
- the last
consecutive_thresholdresults are all errors, or - the error rate within the last
windowresults reaches or exceedswindow_error_rate.
On detection it returns the configured action with a message telling the user
the agent appears stuck. The window is not reset on firing — a thrashing
agent tends to keep failing, so the policy keeps firing until the user
intervenes or the agent recovers naturally (successful results push old errors
out of the window).
# Omnigent config (policies block)
policies:
catch_stuck_agent:
type: function
handler: omnigent.policies.builtins.context.detect_thrashing
factory_params:
consecutive_threshold: 5 # fire after 5 errors in a row (0 disables)
window: 10 # rolling window for the rate check
window_error_rate: 0.8 # fire at ≥80% errors in the window (0 disables)
action: ASK # ASK escalates to the user; DENY blocks the next resultBoth checks are independent — set consecutive_threshold: 0 to rely purely on
the window error rate, or window_error_rate: 0 to rely purely on the
consecutive-error run.
Track custom state from a CEL expression
cel_policy evaluates a CEL (Common Expression Language) expression
against every policy event. The expression must return a map with a result
key ("DENY", "ASK", or "ALLOW") and may add an optional reason. A
non-map return (or a map without a valid result) abstains, passing to the
next policy. Because CEL is non-Turing-complete and side-effect-free, the
expression itself can't mutate anything.
To let a CEL policy accumulate its own session state
across turns, the returned map may also include a state_updates key. It must
be a list of maps, each shaped:
{ "key": string, "action": "set" | "increment" | "delete" | "append", "value": any }
The action values behave as follows, and value is required for set,
increment, and append and ignored for delete:
| Action | Effect |
|---|---|
set | Store value at key, replacing any existing value. |
increment | Add value to the number stored at key. |
append | Append value to the list stored at key. |
delete | Remove key from session state (value is ignored). |
For example, this policy allows every tool call while counting them and recording the last tool name in session state:
# Omnigent config (policies block)
policies:
count_tool_calls:
type: function
handler: omnigent.policies.builtins.cel.cel_policy
factory_params:
expression: |
event.type == "tool_call"
? {
"result": "ALLOW",
"state_updates": [
{"key": "call_count", "action": "increment", "value": 1},
{"key": "last_tool", "action": "set", "value": event.data.name}
]
}
: {"result": "ALLOW"}State written this way is shared session state, so a later policy (or a later evaluation of the same CEL expression) can read it back and branch on it, just like the stateful builtin policies do.
Make spend visible before you restrict it
Start with soft thresholds only. Engineers see when they're running an expensive session and can decide whether the task warrants it. No one gets blocked; habits change on their own.
# Omnigent config (policies block)
policies:
session_visibility:
type: function
handler: omnigent.policies.builtins.cost.cost_budget
factory_params:
ask_thresholds_usd: [1.0, 5.0]
max_cost_usd: 999.0 # effectively no hard cap
daily_visibility:
type: function
handler: omnigent.policies.builtins.cost.user_daily_cost_budget
factory_params:
ask_thresholds_usd: [10.0, 25.0]
max_cost_usd: 999.0This gives you real data on where spend is concentrated before you decide where to add guardrails.
Server-wide team policy
A reasonable starting point for a team deployment: per-user daily visibility at $25, a soft check at $50. Engineers can still use any model for any task — they just get asked before spending more than $25 in a day.
# config.yaml
policies:
daily_budget:
type: function
function:
path: omnigent.policies.builtins.cost.user_daily_cost_budget
arguments:
ask_thresholds_usd: [25.0, 50.0]
max_cost_usd: 100.0omnigent server -c config.yaml
The daily cap exists to surface sessions that are genuinely off the rails, not to penalize productive use.
Keep sessions focused
Use this policy to keep sessions focused and avoid wasting tokens on stale context.
On each user request, it classifies whether the latest message continues the
current task or starts a new one, and returns the configured action when it
detects a task switch. It requires a server llm: config and fails open if no
LLM client is available.
# Omnigent config (policies block)
policies:
keep_context_lean:
type: function
handler: omnigent.policies.builtins.context.detect_task_switch
factory_params:
min_turns: 2
history_window: 4
action: ASK