BlockRunAI · VickyXAI · Aug 31, 2026 · Aug 31, 2026 · Aug 31, 2026 · Aug 31, 2026
diff --git a/ECOSYSTEM.md b/ECOSYSTEM.md
@@ -165,7 +165,7 @@ Want to add an integration? [Open an issue](https://github.com/blockrunai/awesom
 
 | Profile | Strategy | Example Models |
 |---------|----------|----------------|
-| `free` | Free models only | Step 3.7 Flash (NVIDIA-hosted free tier, no wallet needed) |
+| `free` | Free models only | Nemotron 3.5 Lightning (NVIDIA-hosted free tier, no wallet needed) |
 | `eco` | Cheapest capable | DeepSeek, Gemini Flash Lite |
 | `auto` | Balanced cost/quality | GPT-5 Mini, Gemini Flash |
 | `premium` | Best quality | Claude Opus 5, GPT-5.6 Sol |
@@ -186,7 +186,7 @@ BlockRun routes to these AI providers via x402:
 | Qwen | Qwen3.7 Max (1M context, Alibaba flagship), Qwen3.7 Plus, Qwen3.7 Flash | $0.03–$1.48 / $0.13–$4.43 |
 | Tencent | Hy3 | $0.132 / $0.528 |
 | Xiaomi | MiMo-V2.5 Pro | $0.435 / $0.87 |
-| NVIDIA | Step 3.7 Flash, Nemotron 3 Nano Omni, Nemotron Nano 9B v2, Nemotron Nano 12B v2 VL, Mistral Nemotron (5 free models, keyless — no wallet needed) | **Free** |
+| Free tier | Nemotron 3 Ultra 550B, Nemotron 3.5 Lightning, Nemotron 3 Nano 30B, Nemotron 3 Nano Omni (vision), Llama 3.2 11B Vision, Cohere North Mini Code, Poolside Laguna XS 2.1 (7 free models, keyless — no wallet needed) | **Free** |
 
 ### Image Models
 

diff --git a/README.md b/README.md
@@ -138,7 +138,7 @@ Real-time prediction market data powered by Predexon:
 | **Qwen** | Qwen3.7 Max (1M context, Alibaba flagship), Qwen3.7 Plus, Qwen3.7 Flash | $0.03–$1.48 / $0.13–$4.43 |
 | **Tencent** | Hy3 | $0.132 / $0.528 |
 | **Xiaomi** | MiMo-V2.5 Pro | $0.435 / $0.87 |
-| **NVIDIA** | Step 3.7 Flash, Nemotron 3 Nano Omni, Nemotron Nano 9B v2, Nemotron Nano 12B v2 VL, Mistral Nemotron (5 free models, keyless — no wallet needed) | **Free** |
+| **Free tier** | Nemotron 3 Ultra 550B, Nemotron 3.5 Lightning, Nemotron 3 Nano 30B, Nemotron 3 Nano Omni (vision), Llama 3.2 11B Vision, Cohere North Mini Code, Poolside Laguna XS 2.1 (7 free models, keyless — no wallet needed) | **Free** |
 
 ### Reasoning
 
@@ -290,7 +290,7 @@ Full directory with one line per public repo: [Ecosystem docs](./docs/resources/
 
 | Profile | Strategy | Example Models |
 |---------|----------|----------------|
-| `free` | Free models only | Step 3.7 Flash (NVIDIA-hosted free tier, no wallet needed) |
+| `free` | Free models only | Nemotron 3.5 Lightning (NVIDIA-hosted free tier, no wallet needed) |
 | `eco` | Cheapest capable | DeepSeek, Gemini Flash Lite |
 | `auto` | Balanced cost/quality | GPT-5 Mini, Gemini Flash |
 | `premium` | Best quality | Claude Opus 5, GPT-5.6 Sol |

diff --git a/docs/README.md b/docs/README.md
@@ -7,7 +7,7 @@ description: BlockRun is the routing and payment layer for AI agents — one end
 
 **Agents that pay, spend, and trade.**
 
-BlockRun is economic infrastructure for the agent era. AI agents discover services, pay in USDC over the [x402 protocol](x402/how-it-works.md), and execute autonomously — **no API keys, no subscriptions, no credit card.** One funded wallet unlocks 71 LLMs, media generation, real-time data, and on-chain execution.
+BlockRun is economic infrastructure for the agent era. AI agents discover services, pay in USDC over the [x402 protocol](x402/how-it-works.md), and execute autonomously — **no API keys, no subscriptions, no credit card.** One funded wallet unlocks 73 LLMs, media generation, real-time data, and on-chain execution.
 
 :::tip{title="In a hurry?"}
 Jump to the [5-Minute Quickstart](getting-started/quickstart.md) and make your first paid call.
@@ -38,7 +38,7 @@ Pick the path that matches how you work.
 ::::cards
 
 :::card{title="I want an autonomous agent" href="products/franklin.md" icon="Rocket"}
-Franklin — the AI agent with a wallet. Writes code and spends USDC across 71 models and paid APIs. Free to start.
+Franklin — the AI agent with a wallet. Writes code and spends USDC across 73 models and paid APIs. Free to start.
 :::
 
 :::card{title="I use Claude Code / Cursor" href="getting-started/quickstart.md" icon="Terminal"}
@@ -62,7 +62,7 @@ Four product families, one payment layer.
 ::::cards
 
 :::card{title="Intelligence" href="products/intelligence/overview.md" icon="Brain"}
-71 LLMs (GPT, Claude, Gemini, DeepSeek, Grok, Kimi, Llama) through one OpenAI-compatible API. Pay per request.
+73 LLMs (GPT, Claude, Gemini, DeepSeek, Grok, Kimi, Llama) through one OpenAI-compatible API. Pay per request.
 :::
 
 :::card{title="Routing" href="products/routing/clawrouter.md" icon="Route"}

diff --git a/docs/api-reference/chat-completions.md b/docs/api-reference/chat-completions.md
@@ -1,6 +1,6 @@
 ---
 title: Chat Completions
-description: OpenAI-compatible Chat Completions endpoint for 71 LLMs, paid per request in USDC over x402 — no API keys, no subscriptions.
+description: OpenAI-compatible Chat Completions endpoint for 73 LLMs, paid per request in USDC over x402 — no API keys, no subscriptions.
 ---
 
 # Chat Completions
@@ -172,14 +172,16 @@ WWW-Authenticate: X402 requirements="<same value>"
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{"scheme": "exact", "network": "eip155:8453", "amount": "25685", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300}],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "price": {"amount": "0.025685", "currency": "USD"},
   "paymentInfo": {"network": "base", "asset": "USDC", "x402Version": 2}
 }
 ```
 
-`price.amount` is the exact amount the header signs, transaction fee included. Decoded, the header is:
+`price.amount` is the exact amount the header signs, transaction fee included. `x402Version`/`accepts` at the top level mirror the header's challenge in the body, for clients that only parse the body. Decoded, the header is:
 
 ```json
 {
@@ -328,7 +330,7 @@ console.log(result.choices[0].message.content);
 ::::cards
 
 :::card{title="Browse all models" href="models.md" icon="Brain"}
-71 chat models with live pricing — pick the right model and ID for your call.
+73 chat models with live pricing — pick the right model and ID for your call.
 :::
 
 :::card{title="Error handling" href="errors.md" icon="Code"}

diff --git a/docs/api-reference/defillama.md b/docs/api-reference/defillama.md
@@ -125,10 +125,13 @@ DefiLlama does not know is simply absent from `coins` — the call still returns
 A request without a payment header returns `402`. The signed requirements are
 in the `X-Payment-Required` / `PAYMENT-REQUIRED` headers (and
 `WWW-Authenticate: X402 requirements="…"`), and the JSON body restates the
-price for humans:
+price for humans and mirrors the challenge itself (`x402Version`, `accepts`)
+for clients that only read the body:
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{ "scheme": "exact", "network": "eip155:8453", "amount": "2000", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300 }],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "endpoint": "/api/v1/defillama/prices/coingecko:bitcoin",

diff --git a/docs/api-reference/errors.md b/docs/api-reference/errors.md
@@ -93,14 +93,16 @@ An unknown model is a plain-string error that suggests live IDs:
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{"scheme": "exact", "network": "eip155:8453", "amount": "25685", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300}],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "price": {"amount": "0.025685", "currency": "USD"},
   "paymentInfo": {"network": "base", "asset": "USDC", "x402Version": 2}
 }
 ```
 
-The signed requirements travel in the `X-Payment-Required` / `PAYMENT-REQUIRED` headers (and `WWW-Authenticate: X402 requirements="…"`). `price.amount` equals the signed amount, including the flat $0.001 transaction fee.
+The signed requirements travel in the `X-Payment-Required` / `PAYMENT-REQUIRED` headers (and `WWW-Authenticate: X402 requirements="…"`), and — since 2026-08-30 — are mirrored at the top level of the JSON body too (`x402Version`, `accepts`), byte-identical to the decoded header. This is for v1-era x402 clients (early `x402-fetch`/`x402-axios` and third-party wrappers) that only parse the body and silently fail to auto-pay when there's no top-level `accepts`. `price.amount` equals the signed amount, including the flat $0.001 transaction fee.
 
 :::info{title="402 is not an error"}
 A `402 Payment Required` is part of the normal x402 flow — the gateway is quoting a price. Sign and retry with payment and the SDKs handle this round-trip automatically.

diff --git a/docs/api-reference/exa-search.md b/docs/api-reference/exa-search.md
@@ -326,10 +326,12 @@ Every price above already includes the flat $0.001 per-transaction fee (base $0.
 
 ### The 402 response
 
-An unpaid request returns `402` with the exact charge in the body and the signable x402 v2 requirements in the `X-Payment-Required` / `PAYMENT-REQUIRED` headers (base64 JSON; also mirrored in `WWW-Authenticate`). For `/contents` the body is read first, so `price.amount` reflects `urls.length`:
+An unpaid request returns `402` with the exact charge in the body and the signable x402 v2 requirements in the `X-Payment-Required` / `PAYMENT-REQUIRED` headers (base64 JSON; also mirrored in `WWW-Authenticate`), plus the same challenge mirrored into the body as `x402Version`/`accepts`. For `/contents` the body is read first, so `price.amount` reflects `urls.length`:
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{ "scheme": "exact", "network": "eip155:8453", "amount": "5000", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300 }],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "endpoint": "/api/v1/exa/contents",
@@ -391,7 +393,7 @@ Real-time web and news search via Grok Live Search.
 :::
 
 :::card{title="Chat Completions" href="chat-completions.md" icon="Brain"}
-Feed grounded search results into any of 71 LLMs for synthesis.
+Feed grounded search results into any of 73 LLMs for synthesis.
 :::
 
 :::card{title="Error handling" href="errors.md" icon="Code"}

diff --git a/docs/api-reference/image-generation.md b/docs/api-reference/image-generation.md
@@ -337,10 +337,12 @@ billed = catalog rate for the size × n × 1.05   (5% platform margin on media)
 
 ### 402 responses
 
-The unpaid `402` is a normal x402 challenge: the signable requirements live in the `X-Payment-Required` / `PAYMENT-REQUIRED` / `WWW-Authenticate` headers (base64 JSON, `x402Version: 2`, `maxTimeoutSeconds: 600`); the body is informational.
+The unpaid `402` is a normal x402 challenge: the signable requirements live in the `X-Payment-Required` / `PAYMENT-REQUIRED` / `WWW-Authenticate` headers (base64 JSON, `x402Version: 2`, `maxTimeoutSeconds: 600`), mirrored at the top of the body (`x402Version`, `accepts`) for clients that only read the body; the rest of the body is informational.
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{ "scheme": "exact", "network": "eip155:8453", "amount": "53500", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 600 }],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "price": { "amount": "0.053500", "currency": "USD", "pricePerImage": 0.05, "totalImages": 1 },

diff --git a/docs/api-reference/modal-sandbox.md b/docs/api-reference/modal-sandbox.md
@@ -177,10 +177,13 @@ curl -X POST https://blockrun.ai/api/v1/modal/sandbox/create \
 
 The signed requirements are in the `X-Payment-Required` / `PAYMENT-REQUIRED`
 headers (and `WWW-Authenticate: X402 requirements="…"`); the body restates the
-price:
+price and mirrors the challenge itself (`x402Version`, `accepts`) for clients
+that only read the body:
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{ "scheme": "exact", "network": "eip155:8453", "amount": "11000", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300 }],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "endpoint": "/api/v1/modal/sandbox/create",

diff --git a/docs/api-reference/models.md b/docs/api-reference/models.md
@@ -238,11 +238,13 @@ Open-weight models served free of charge (no x402 payment), subject to a small p
 
 | Model ID | Name | Input Price | Output Price |
 |----------|------|-------------|--------------|
-| `nvidia/nemotron-3-nano-omni-30b-a3b-reasoning` | Nemotron 3 Nano Omni | **FREE** | **FREE** |
-| `nvidia/mistral-nemotron` | Mistral Nemotron | **FREE** | **FREE** |
-| `nvidia/step-3.7-flash` | StepFun Step 3.7 Flash | **FREE** | **FREE** |
-| `nvidia/nemotron-nano-9b-v2` | Nemotron Nano 9B v2 | **FREE** | **FREE** |
-| `nvidia/nemotron-nano-12b-v2-vl` | Nemotron Nano 12B v2 VL | **FREE** | **FREE** |
+| `nvidia/nemotron-3-ultra-550b` | Nemotron 3 Ultra 550B (1M ctx) | **FREE** | **FREE** |
+| `nvidia/nemotron-3.5-lightning` | Nemotron 3.5 Lightning (1M ctx) | **FREE** | **FREE** |
+| `nvidia/nemotron-3-nano-30b` | Nemotron 3 Nano 30B | **FREE** | **FREE** |
+| `nvidia/nemotron-3-nano-omni-30b-a3b-reasoning` | Nemotron 3 Nano Omni (vision) | **FREE** | **FREE** |
+| `nvidia/llama-3.2-11b-vision` | Llama 3.2 11B Vision | **FREE** | **FREE** |
+| `cohere/north-mini-code` | Cohere North Mini Code (coding) | **FREE** | **FREE** |
+| `poolside/laguna-xs-2.1` | Poolside Laguna XS 2.1 (coding) | **FREE** | **FREE** |
 
 ### Image Generation
 

diff --git a/docs/api-reference/polymarket-funding.md b/docs/api-reference/polymarket-funding.md
@@ -77,6 +77,8 @@ curl -X POST https://blockrun.ai/api/v1/polymarket/fund
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{ "scheme": "exact", "network": "eip155:8453", "amount": "11000", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300 }],
   "error": "Payment Required",
   "message": "This endpoint requires an x402 fee payment ($0.0110). Include the signed deposit authorization in the body.",
   "endpoint": "/api/v1/polymarket/fund",

diff --git a/docs/api-reference/realface.md b/docs/api-reference/realface.md
@@ -182,7 +182,7 @@ POST https://blockrun.ai/api/v1/realface/enroll
 
 Same two-step pattern as other paid BlockRun endpoints:
 
-1. First call without `X-Payment` → server returns `402 Payment Required` with x402 challenge headers (`X-Payment-Required` / `PAYMENT-REQUIRED` base64, plus `WWW-Authenticate: X402 requirements="…"`) and a body of `{ "error": "Payment Required", "message": "Enrolling a RealFace asset costs $0.0110 USDC. …", "price": { "amount": "0.0110", "currency": "USD" }, "paymentInfo": { "network": "base", "asset": "USDC", "x402Version": 2 } }`
+1. First call without `X-Payment` → server returns `402 Payment Required` with x402 challenge headers (`X-Payment-Required` / `PAYMENT-REQUIRED` base64, plus `WWW-Authenticate: X402 requirements="…"`) and a body of `{ "x402Version": 2, "accepts": [{ "scheme": "exact", "network": "eip155:8453", "amount": "11000", "payTo": "0x…", "maxTimeoutSeconds": 300 }], "error": "Payment Required", "message": "Enrolling a RealFace asset costs $0.0110 USDC. …", "price": { "amount": "0.0110", "currency": "USD" }, "paymentInfo": { "network": "base", "asset": "USDC", "x402Version": 2 } }` — `x402Version`/`accepts` mirror the header's challenge for clients that only read the body
 2. Sign the EIP-3009 transfer authorization for **$0.011 USDC on Base** (`$0.01` enrolment + `$0.001` transaction fee — the requirements say `11000` micro-USDC)
 3. Retry the same request with `X-Payment: <base64>` (`Payment-Signature` is accepted too)
 

diff --git a/docs/api-reference/responses.md b/docs/api-reference/responses.md
@@ -69,13 +69,15 @@ The quote is estimated input tokens plus **10% of `max_output_tokens`** at the m
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{"scheme": "exact", "network": "eip155:8453", "amount": "24685", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300}],
   "error": {"message": "This endpoint requires x402 payment", "type": "payment_required", "param": null, "code": null},
   "price": {"amount": "0.024685", "currency": "USD"},
   "paymentInfo": {"network": "base", "asset": "USDC", "x402Version": 2}
 }
 ```
 
-The signed requirements are in the `X-Payment-Required` / `PAYMENT-REQUIRED` / `WWW-Authenticate` headers; the header amount is authoritative and includes the transaction fee, and the body `price.amount` quotes the same fee-inclusive number. A payment that fails verification is a `402` in the same OpenAI envelope — `"Payment verification failed: …"` — and a reused authorization is `402` `"Payment authorization already used — sign a fresh authorization for each request."`; this endpoint keeps OpenAI's error schema rather than the `code` field the native BlockRun endpoints carry. Nothing is charged on either.
+The signed requirements are in the `X-Payment-Required` / `PAYMENT-REQUIRED` / `WWW-Authenticate` headers; the header amount is authoritative and includes the transaction fee, and the body `price.amount` quotes the same fee-inclusive number. `x402Version`/`accepts` at the top of the body mirror that header challenge for clients that only read the body — they sit alongside the OpenAI-shaped `error` object, not inside it. A payment that fails verification is a `402` in the same OpenAI envelope — `"Payment verification failed: …"` — and a reused authorization is `402` `"Payment authorization already used — sign a fresh authorization for each request."`; this endpoint keeps OpenAI's error schema rather than the `code` field the native BlockRun endpoints carry. Nothing is charged on either.
 
 ## Examples
 

diff --git a/docs/api-reference/search.md b/docs/api-reference/search.md
@@ -74,6 +74,15 @@ When you first make a request without payment, you'll receive:
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{
+    "scheme": "exact",
+    "network": "eip155:8453",
+    "amount": "263500",
+    "asset": "0x8335…",
+    "payTo": "0x…",
+    "maxTimeoutSeconds": 300
+  }],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "price": {
@@ -90,7 +99,7 @@ When you first make a request without payment, you'll receive:
 }
 ```
 
-The full x402 v2 payment requirements are in the `X-Payment-Required` and `PAYMENT-REQUIRED` headers (base64 JSON, identical content) and in `WWW-Authenticate: X402 requirements="..."`. Sign against the header, not the body: `price.amount` in the body is the per-source cost plus margin **before** the flat $0.001 transaction fee, while `accepts[0].amount` in the header is the exact USDC (6-decimal) amount you will be charged — for the default 10 sources that is `263500`, i.e. $0.2635. Payment authorizations are valid for `maxTimeoutSeconds: 300`.
+The full x402 v2 payment requirements are in the `X-Payment-Required` and `PAYMENT-REQUIRED` headers (base64 JSON, identical content) and in `WWW-Authenticate: X402 requirements="..."`, and are now also mirrored at the top of the JSON body as `x402Version`/`accepts` (for clients that only read the body). Sign against `accepts[0].amount` (header or body, they're identical), not `price.amount`: `price.amount` is the per-source cost plus margin **before** the flat $0.001 transaction fee, while `accepts[0].amount` is the exact USDC (6-decimal) amount you will be charged — for the default 10 sources that is `263500`, i.e. $0.2635. Payment authorizations are valid for `maxTimeoutSeconds: 300`.
 
 A `GET` to the same URL returns a 402 quoting the default price (10 sources) — useful for discovery.
 

diff --git a/docs/api-reference/text-to-speech.md b/docs/api-reference/text-to-speech.md
@@ -83,10 +83,12 @@ Differences from the ElevenLabs models:
 
 ### The 402 challenge
 
-An unpaid POST returns `402` with the x402 requirement in the `X-Payment-Required` / `PAYMENT-REQUIRED` / `WWW-Authenticate` headers and an informational body:
+An unpaid POST returns `402` with the x402 requirement in the `X-Payment-Required` / `PAYMENT-REQUIRED` / `WWW-Authenticate` headers, mirrored at the top of the body as `x402Version`/`accepts`; the rest of the body is informational:
 
 ```json
 {
+  "x402Version": 2,
+  "accepts": [{ "scheme": "exact", "network": "eip155:8453", "amount": "53500", "asset": "0x8335…", "payTo": "0x…", "maxTimeoutSeconds": 300 }],
   "error": "Payment Required",
   "message": "This endpoint requires x402 payment",
   "price": { "amount": "0.053500", "currency": "USD" },