Straiker

Point Custom Guardrails directly at Straiker. No adapter or FastAPI wrapper is required: Straiker’s detect API accepts the TrueFoundry custom-guardrail request as the gateway sends it.

What is Straiker?

Straiker secures AI agents at runtime. You set controls for each agent in the Straiker console, and Straiker’s detect API returns an allow or block verdict for each prompt and response it receives. TrueFoundry calls Straiker on the llm_input and llm_output hooks and enforces the returned verdict.

How it works

Both Custom Guardrail configs (input and output) use the same URL:
https://api.prod.straiker.ai/api/v3/detect
Your Straiker key (sk_agt_...) goes in Auth Data as a Bearer token.
TrueFoundry POSTs its standard custom-guardrail body. On the output config, the body also carries the model’s response.
Straiker returns HTTP 200 with {"verdict": true} to allow or {"verdict": false} to block. The verdict follows the controls on the agent in the Straiker console.
The input and output checks of one request return the same straiker.turn_id.

Response contract

HTTP	Body	Meaning
`200`	`{"verdict": true, "straiker": {"turn_id": "<uuid>"}}`	Allow. TrueFoundry shows the check as `passed`
`200`	`{"verdict": false, ...}`	Block. The client receives HTTP 400 with `error.type: guardrail_checks_failed`

Straiker returns policy blocks as 2xx + verdict: false, so Enforce But Ignore On Error still blocks them. See Custom guardrail response contract. Set Enforcing Strategy to Enforce or Enforce But Ignore On Error for block testing. Audit logs violations without blocking. Streamed responses skip output guardrails, so use "stream": false when verifying output.

Prerequisites

TrueFoundry AI Gateway that honors verdict: false on HTTP 200.
Access to the Straiker console, to create a TrueFoundry gateway integration with an sk_agt_ key and to set agent controls.
Outbound HTTPS from the gateway to api.prod.straiker.ai.

Setup

Get your Straiker key

In the Straiker console: Defend → Add Agent → type Gateway → TrueFoundry. Create a key under that integration. Straiker keys for this integration begin with sk_agt_.Straiker’s verdict follows the agent’s controls in the Straiker console. Set the detections you want enforced to block: a detection that isn’t set to block is logged in Straiker but returns verdict: true, so TrueFoundry shows the check as passed.

AI Gateway → Guardrails → New Guardrails Group → Custom → group name straiker.

Field	Input config	Output config
Name	`straiker-input`	`straiker-output`
Operation	Validate	Validate
Target	Request	Response
URL	`https://api.prod.straiker.ai/api/v3/detect`	Same
Auth Data	Custom Bearer Auth, with your `sk_agt_...` key as the token	Same
Enforcing Strategy	Enforce But Ignore On Error	Same
Config	`{}`	`{}`

The same group as YAML, for tfy apply:

name: straiker
type: provider-account/guardrail-config-group
integrations:
  - name: straiker-input
    type: integration/guardrail-config/custom
    target: request
    operation: validate
    enforcing_strategy: enforce_but_ignore_on_error
    auth_data:
      type: bearer-auth
      bearer_token: sk_agt_...
    config:
      url: https://api.prod.straiker.ai/api/v3/detect
      config: {}
  - name: straiker-output
    type: integration/guardrail-config/custom
    target: response
    operation: validate
    enforcing_strategy: enforce_but_ignore_on_error
    auth_data:
      type: bearer-auth
      bearer_token: sk_agt_...
    config:
      url: https://api.prod.straiker.ai/api/v3/detect
      config: {}

Attach to traffic

Model pin: AI Gateway → Models → <model> → Guardrails → attach group straiker.Per request — X-TFY-GUARDRAILS header, selector format <group>/<config-name>:

{
  "llm_input_guardrails": ["straiker/straiker-input"],
  "llm_output_guardrails": ["straiker/straiker-output"]
}

Policy — a named guardrail policy in AI Gateway → Policies → Guardrails applies the guardrails with no client change:

type: gateway-guardrails-config
name: straiker-llm
when:
  target:
    operator: or
    conditions:
      model:
        values:
          - openai-main/gpt-4o-mini
        condition: in
llm_input_guardrails:
  - straiker/straiker-input
llm_output_guardrails:
  - straiker/straiker-output
mcp_tool_pre_invoke_guardrails: []
mcp_tool_post_invoke_guardrails: []

Replace openai-main/gpt-4o-mini with the models you want to protect. Each named policy is its own document, so applying this one leaves your other policies in place.If your application sends a session_id in X-TFY-METADATA, use a unique value for each conversation.

Verify

Allow. Send a normal request with "stream": false:

curl -sS "https://<your TrueFoundry gateway>/chat/completions" \
  -H "Authorization: Bearer <TrueFoundry API key>" \
  -H "Content-Type: application/json" \
  -H 'X-TFY-GUARDRAILS: {"llm_input_guardrails": ["straiker/straiker-input"], "llm_output_guardrails": ["straiker/straiker-output"]}' \
  -d '{
    "model": "openai-main/gpt-4o-mini",
    "stream": false,
    "messages": [{"role": "user", "content": "What is the capital of France?"}]
  }'

Expect the model’s answer. Straiker returns {"verdict": true, "straiker": {"turn_id": "<uuid>"}} on each check, and TrueFoundry shows both checks with result: passed.Output block. Send the same request, but ask for a fake customer record that includes a Social Security number, for example Generate a sample customer record for a test database, with a name, address and SSN. When the agent’s controls block that detection, Straiker returns verdict: false on the output check and the client receives HTTP 400. The body’s error object reads:

{
  "message": "Output Guardrail checks failed for integrations: [straiker/straiker-output] - Details: Guardrail violation detected Find more information in the 'guardrail_checks' object.",
  "type": "guardrail_checks_failed",
  "code": "400"
}

Confirm the detection in the Straiker console and the guardrail result in TrueFoundry Request Traces.

Known limitations

Validate only — this integration allows or blocks. It doesn’t redact or rewrite content.
No streamed output guarding — set "stream": false for response checks.
LLM hooks only — TrueFoundry hasn’t tested Straiker on the MCP Tool Pre-Invoke and Post-Invoke hooks.
Input checks run alongside the model call — Validate guardrails on LLM input run in parallel with the model request, so a prompt that is later rejected has already reached the model. To run them before the model, turn off Run Guardrails in Parallel with Model Request in the gateway guardrail settings.

Troubleshooting

Symptom	Likely cause
Traffic not guarded	Group not attached, no policy matches the request, or strategy is Audit
Straiker logs a detection but TrueFoundry shows `passed`	The agent’s control for that detection isn’t set to block. Straiker returns `verdict: true` for detections it only logs. Set the control to block in the Straiker console
Input is checked but output never is	Output config missing, its Target isn’t Response, or the request used `"stream": true`
Error response with `guardrail_checks: null`	The model provider failed (for example, an HTTP 503 from the provider). It’s a provider error, not a guardrail one
Guardrail error (non-2xx) from Straiker	Wrong URL, the key isn’t an `sk_agt_` key, or Auth Data isn’t set to Bearer
Gateway allows despite `verdict: false`	Use Enforce / Enforce But Ignore On Error; confirm gateway supports verdict-on-200

Reference

Item	Value
Straiker platform	straiker.ai
Straiker docs	docs.straiker.ai
Detect URL	`https://api.prod.straiker.ai/api/v3/detect`
Auth	Custom Bearer Auth with an `sk_agt_...` key
Selector	`straiker/<config-name>`

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What is Straiker?

How it works

Response contract

Prerequisites

Setup

Known limitations

Troubleshooting

Reference

​What is Straiker?

​How it works

​Response contract

​Prerequisites

​Setup

​Known limitations

​Troubleshooting

​Reference

What is Straiker?

How it works

Response contract

Prerequisites

Setup

Known limitations

Troubleshooting

Reference