Inspect the contract.
Choose the integration.

Put it where your stack already is.

The Photon research preview has API, SDK and MCP references. These interfaces describe their own contract; the wider catalog has method-specific dependencies and access.

Photon Base as a smart honesty router.

The served model, registry grounding, readout pre-filter and escalation routes are separate components. The pre-filter does not establish fabrication detection. Inspect the response record and known failures beside the system contract.

curl https://honesty.tools/v1/chat/completions \
  -H "Authorization: Bearer $APERTURE_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "aperture-router",
    "messages": [{"role":"user","content":"Who founded Brindlewick & Thorne?"}]
  }'

from openai import OpenAI

client = OpenAI(base_url="https://honesty.tools/v1", api_key=APERTURE_KEY)

resp = client.chat.completions.create(
    model="aperture-router",
    messages=[{"role": "user", "content": "Who founded Brindlewick & Thorne?"}],
)
print(resp.choices[0].message.content)        # the answer
print(resp.model_extra["aperture"])           # the honesty layer ↓

import OpenAI from "openai";

const client = new OpenAI({ baseURL: "https://honesty.tools/v1", apiKey: APERTURE_KEY });

const resp = await client.chat.completions.create({
  model: "aperture-router",
  messages: [{ role: "user", content: "Who founded Brindlewick & Thorne?" }],
});
console.log(resp.choices[0].message.content);   // the answer
console.log(resp.aperture);                  // the honesty layer ↓

Every reply carries an aperture block — the certificate and the route trace — alongside the standard OpenAI response. Standard clients ignore it; Aperture-aware ones read it.

{
  "choices": [{ "message": { "role": "assistant", "content": "…" } }],
  "aperture": {
    "verdict":  "OFF_MAP",           // GROUNDED · CONFIDENT · LOW_FAMILIARITY · OFF_MAP
    "off_map":  0.778,              // aperture-router's familiarity off-map read (a different instrument from the per-model cert fingerprint), 0–1
    "route": {
      "tier": 2,                   // 1 local · 2 neocortex · 3 internet
      "brain": "the escalated neocortex model",
      "escalated": true,
      "reason": "off the map (off-distribution 0.78) — escalated to the neocortex"
    },
    "gauges":  { "off_distribution": 0.778, "familiarity": 0.022 },
    "advice":  "the question is outside the model's reliable knowledge…"
  }
}

The model id doubles as the mode — switch behavior without touching your code — and for already-recorded answers, POST /v1/audit scores a whole batch in one keyed call (see the docs):

Every answer ships a signed receipt.

Whether a receipt is authentic isn't something you take on faith — every /v1/verify receipt (and every stored /read) is signed: an ed25519 signature you can verify offline against the published public key. Tamper with one byte and it fails. This is the moat: not raw metrics — a verifiable record.

import json, base64
from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PublicKey

# `receipt` is the signed block from your /v1/verify response (or a stored /read)
r = dict(receipt); sig = r.pop("signature"); r.pop("id", None)
canon = json.dumps(r, sort_keys=True, separators=(",", ":"), ensure_ascii=False).encode()
Ed25519PublicKey.from_public_bytes(base64.b64decode(sig["pub"])).verify(base64.b64decode(sig["sig"]), canon)
print("verified — the signed receipt is authentic")   # raises on tamper; sig["pub"] == /api/cert/pubkey

One key. One import.

The existing Photon package and service-specific examples are retained below. Consult the access and billing contract before using the hosted service.

pip install aperture-gate

# one sk-apt- key — grounding + honest inference, free to start
from aperture_gate import Aperture, signup

key = signup("you@email.com")            # a FREE key (or grab one at honesty.tools/verify)
ap  = Aperture()                          # reads APERTURE_API_KEY

ap.verify("Sotorasenib is an approved cancer drug.")   # → fabricated · caught FREE
ap.verify("BRCA1 is a tumor suppressor gene.")          # → grounded · 1 of your plan
print(ap.ask("Who painted the Mona Lisa?"))            # → honest Photon inference
ap.usage()   # → {tier:"free", used, limit, remaining} · upgrade at honesty.tools/verify

# ADVANCED — gate your OWN model offline, against a calibration certificate (no hosted call)
from aperture_gate import Gate

gate = Gate.from_cert("openai/gpt-4o-mini")        # a registry id, a downloaded JSON, or a dict
r = gate.ask("Who founded Brindlewick & Thorne?",
             base_url="https://openrouter.ai/api/v1", api_key=KEY,
             model="openai/gpt-4o-mini")
print(r["verdict"], r["score"])   # → OFF_MAP — caught before you commit
# or words-only, no model at all:
verdict = gate.read_text(answer_text)

The lens beside the model.

The recommended shape for agents: not baked into weights, but a tool the agent calls mid-task — “am I off the map before I commit?” — at any tool-call, write, or plan→execute boundary. It runs as a stdio MCP server, shipped inside the same package.

// add Aperture to your MCP client's config
{
  "mcpServers": {
    "aperture": {
      "command": "python",
      "args": ["-m", "aperture_gate.mcp"],
      "env": { "APERTURE_API_KEY": "sk-apt-…" }   // a free key from honesty.tools/verify
    }
  }
}

# install once, run anywhere — stdlib only
pip install aperture-gate
python -m aperture_gate.mcp

Three tools, each returning a receipt the agent can branch on:

Then branch on the gate — the whole point is the action: