Add a decision checkpoint.
Keep the workflow you already run.

RUN THIS FIRST · NO ACCOUNT

Start with a local Preflight example.

With Node.js 20+ installed, run the pinned public CLI against its bundled synthetic example:

npx --yes --package deltax-preflight@0.1.1 deltax-preflight-try --example

The command downloads the public package from npm, then checks the example locally. It needs no DeltaX account or API credential and executes no candidate action. Inspect its policy, evidence, admissible candidates, and result before adapting your own inputs.

MCP and GitHub Action setupHosted beta2 contract summary

TWO USEFUL LAYERS

Connect proposal, review, and execution deliberately.

Preflight answers whether candidates meet your explicit policy and evidence requirements. Evaluate answers which bounded review candidate is selected under its fixed profile—or returns a governed refusal. You can use either independently.

1. Keep the trusted inputs outside the proposing agent.

   Pass separate decision, policy, and evidence documents to preflight_check. Bind evidence to the exact decision hash; a source label is not authentication.

2. Handle all four Preflight results.

   REFUSE stops the path. EVIDENCE_REQUIRED needs more evidence. PASS_SINGLE leaves one admissible candidate but grants no permission. Only SELECTION_REQUIRED creates the optional selection handoff.

3. Minimize the API request.

   The optional bridge exports buildEvaluateRequest and reconcileEvaluateResponse. Send only admissible review candidates with explicit objective and scalar context. The bridge excludes external candidates and does not copy the full policy or evidence documents into the request.

4. Submit from your server, then reconcile.

   Your authorized transport supplies the token and stable idempotency key. Reconcile the direct Evaluate response. Reject any selection outside the admissible set, any unexpected contract version, or any true authority/effect flag.

5. Store both records; retain execution control.

   Keep the Preflight receipt, request identity, Evaluate result, and later human decision together. A new proposal requires fresh evidence. Your application separately authorizes and records any eventual action.

Read the bridge contract · MCP setup and tools · Explore application patterns

FREE ACCOUNT API

Make your first bounded review.

Your account connects to the 2026-09-16.beta2 evaluation contract. The account gateway handles authentication, the monthly allowance, and receipt history.

1. Create your Free account.

Create free account, then open API access and create a credential. Free accounts include 100 evaluations each calendar month, resetting at 00:00 UTC on the first day. No card is required.

2. Exchange your credential for a token.

Set DELTAX_CLIENT_ID and DELTAX_CLIENT_SECRET in your server environment. Send URL-encoded form data, not JSON:

curl --fail-with-body 'https://access-api.deltaxevaluate.com/api/builder/oauth/token' \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  --data-urlencode 'grant_type=client_credentials' \
  --data-urlencode "client_id=$DELTAX_CLIENT_ID" \
  --data-urlencode "client_secret=$DELTAX_CLIENT_SECRET" \
  --data-urlencode 'scope=deltax:evaluate'

Save the returned access_token as DELTAX_ACCESS_TOKEN. The response includes token_type: Bearer, expires_in: 900 (15 minutes), and scope: deltax:evaluate. Keep both the secret and token out of browser code and logs.

Standard Python clients work with their default headers. Human verification is required when creating your Free account, not on API requests. Python example and complete account API reference →

3. Send a bounded request.

# Download evaluation.json below and set DELTAX_ACCESS_TOKEN.
curl "https://access-api.deltaxevaluate.com/api/builder/evaluations" \
  -H "Authorization: Bearer $DELTAX_ACCESS_TOKEN" \
  -H 'X-DeltaX-API-Version: 2026-09-16.beta2' \
  -H 'Content-Type: application/json' \
  -H 'Idempotency-Key: my-first-review-001' \
  --data @evaluation.json

The account gateway forwards this request to the evaluator’s POST /v1/evaluations route under the 2026-09-16.beta2 contract. Create a credential in your account first. Reusing the same key and body retrieves the same result without another evaluation.

{
  "profile_id": "deltax-hosted-bounded-review-evaluation-v1",
  "objective": "Choose a bounded next step for a software release that is missing security evidence.",
  "context": {
    "evidence_kind": "synthetic_test",
    "security_review_complete": false
  },
  "candidates": [
    {
      "candidate_id": "review-missing-evidence",
      "semantic_class": "analyze",
      "description": "Identify the missing security evidence before the release review.",
      "operator_reported_support": 0.92
    },
    {
      "candidate_id": "draft-checklist",
      "semantic_class": "draft",
      "description": "Draft a checklist for the reviewer to complete.",
      "operator_reported_support": 0.75
    },
    {
      "candidate_id": "publish-release",
      "semantic_class": "external",
      "description": "Publish the release immediately. This external option must remain shadow only.",
      "operator_reported_support": 0.99
    }
  ]
}

Keep the contract explicit.

Use profile deltax-hosted-bounded-review-evaluation-v1. Submit 1–8 unique candidates with a class, description, and caller-reported support value.

• analyze, compare, draft, and validate are bounded review classes.
• external is shadow-only and cannot be selected for execution.
• The fixed review profile does not infer arbitrary policies from your objective, context, or descriptions. Those fields bind the request record; supplied facts remain unverified.

Handle both outcomes.

if (result.outcome === "selected") {
  // Persist the selected candidate and receipt for review.
} else if (result.outcome === "governed_noop_refusal") {
  // Stop this path. No candidate was selected.
}
// Neither result grants permission to execute an action.

Validate the response version, reason codes, gates, and authority flags. external_effect and execution-authority flags remain false. A receipt is an integrity reference, not a certification of safety or correctness.

The trace records the evaluation outcome and service checks; it is not a per-candidate ranking explanation. The top-level receipt_id identifies your account’s evaluation record. result.commercial_receipt.receipt_id identifies the evaluator’s receipt. Keep both; they identify different records.

Read the current account API limits, token format, response fields and errors →

Deliberate retries. Clear records.

Free accounts include 100 evaluations per UTC calendar month. Each request accepts 1–8 candidates and a body of at most 32,768 bytes. Keep a stable idempotency key for an unchanged request, retain its request and result together, and stop on a governed refusal.

If a response is uncertain, preserve the original body and key for reconciliation. Do not turn a timeout into a new action or silently switch to an unreviewed path.

Planned subscriptions include Builder with 1,000 evaluation traces per billing month, Teams with 10,000, and custom Enterprise pricing. One completed evaluation produces one trace; exact replay uses no additional allowance. View pricing and the Builder early-adopter offer. Paid signup remains disabled.

Wire it into the workflow you own.

Download the integration checklist to plan the handoff with your team. No email required.

See exactly where this fits in six workflows. Paid customer provisioning remains closed until testing is complete.

Public Preflight. Optional API access.

x402 is disabled and remains in development. Payment would not change the gates or execution authority. Stripe is the planned monthly billing path; paid signup is disabled.

Public Preflight MCP is available now for local policy checks, without a subscription. A remote Evaluate MCP integration over HTTPS is planned so compatible AI clients could use Evaluate without installing a local adapter. It is not available yet, and no release date is announced. Preflight does not call Evaluate automatically. See the release boundaries.

Current Free account API reference →

Current hosted beta2 contract summary →

Use the right version.

The hosted evaluator uses the 2026-09-16.beta2 review contract; Free accounts reach it through the authenticated account gateway. The existing downloadable developer kit is the pinned 2026-09-16.beta1 teaching snapshot; its OpenAPI file is not the Builder billing or account API.

Read the archived beta1 reference · View its pinned OpenAPI file

Bounded evaluation only. A response does not execute or authorize a candidate and is not professional advice, certification, a safety determination, or proof of correctness.