Cortex Blueprint
◆10 AGENTS RETIRED◆1 LOOP◆98% CACHE HIT◆~25K TOKEN PROMPT◆4.8M GOLD SUBSCRIBERS◆$5 PER MONTH◆1M+ USERS◆1 ORDER PER CONVERSATION◆0 OPEN-WEB ACCESS◆$1.31B Q2 2026 REVENUE◆
The architecture Robinhood threw away CTX-0.3

“The loop stays dumb so the model can be smart.”

Robinhood Cortex engineering team · 25 August 2026

Robinhood built an investing agent the way everyone builds them — a router fanning each request out to ten specialists. It shipped. Real users, real money. Then they deleted it, replaced it with one model in a loop with no cleverness in it at all, and published exactly how.

Agents retired10
Loops now1
Core prompt25k
From cache98%
Read the record See the evidence
Cortex · live checking…

A working implementation of the architecture, running against a mock brokerage account — fixed positions, no real money and none of yours. Below is a recorded turn; type your own and it runs for real.

find me liquid covered calls to sell. how much can i earn?
portfolioSummary 142ms Total market value $103,684 · today −$139
accountSummary 88ms ind-1 Individual cash $4,820 · buying power $9,640
skill 1ms # Skill: covered calls
optionsChain 610ms AAPL chain · spot $198.62 · 36 contracts ≤45d
duckdbQuery 31ms strike bid open_interest spread_pct
widgetOptionsTable 2ms [Options table rendered on the client · 6 rows]
You hold 300 AAPL, so three contracts are coverable. Inside 45 days the 205 strike is the only strike that clears the liquidity screen — 1,240 open interest, a 2.1% spread — bidding $4.85, which is $485 a contract and $1,455 across three. That is about 2.4% against the shares committed, and it caps them at $205. Assignment there would realise a long-term gain on two of your three lots and a short-term one on the April lot. I can't place options orders. That has to go through the options interface.
1 round · 6 tool calls · cache 98% · guards 0ms free / 240ms blocking
›
Sourced — 9 exhibits, 6 domains Robinhood or a regulator controls Nothing leaked — every claim was published, filed, or posted by Robinhood Independent — not affiliated with Robinhood Markets, Inc.
01 — The precedent

Everybody built the orchestra.

When agents got hard, the industry answered with structure: routers, planners, a specialist per domain. It was the standard shape for a good reason — a narrow scope per agent was how you kept answers accurate.

Case file 01 · the industry pattern ROUTER → N SPECIALISTS Still the default

Add a layer whenever the agent gets something wrong. Every new capability is a new agent, a new prompt, a new toolset.

The cost stays invisible until you look for it: each layer sits between the model and the user, and every improvement to the model has to survive the trip.

Case file 02 · Robinhood Cortex, v1 10 AGENTS → 1 LOOP Deleted on purpose

Cortex shipped exactly that way in early 2026 — a router fanning each request out to roughly ten agents, each with its own prompt, model calls and API clients. Live, to paying subscribers, with real brokerage accounts behind it.

Then they took it apart. Not because it failed. Because the structure itself was the thing holding them back.

Most teams answer a hard agent by adding scaffolding.
Robinhood removed theirs.

02 — The record

What happened, in order.

Every line is a Robinhood release, a Robinhood engineering post, a filed customer agreement, or the CEO's own account. All of it linked in §06.

27 Mar 2025
Cortex is announcedAt Robinhood's Gold keynote, alongside Strategies and Banking. Days later Vlad Tenev calls it, in his own words, our AI investment tool.
Summer 2025
Digests reaches Gold membersHundreds of thousands of users in months; 95% of those surveyed satisfied. Free to all UK customers from August.
16 Dec 2025
Cortex learns to actReintroduced as an assistant that researches, reads your portfolio and places trades in plain English. Everything in §04 exists because of this day.
Q1 2026
The first Assistant ships — on ten agentsIt did its job. And by the team's own account, the architecture was not shaped to ride a curve where models improve every quarter.
16 Jun 2026
The Assistant Agreement is filedMarketing becomes specification: scope, order types, retrieval boundaries, retention, and the confirmation rule — binding and public.
25 Aug 2026
They publish how they rebuilt itThree named engineers write up the rewrite: the ten agents retired, the minimal loop that replaced them, the caching rule. This page exists because of that post.
03 — The sacrifice

The ten agents were not failing.

No outage, no incident, no regulator forcing a rewrite. The specialist architecture was live, in front of paying subscribers, with real accounts behind it. It was the most capable thing the team had shipped.

What broke first was maintainability: ten specialists meant ten prompts and ten toolsets to update every time the product moved. Then something subtler. The boundaries leaked — holdings belonged to the account agent, but the research agent needed them too for a question as ordinary as market news about my top three holdings.

And the router grouped its calls once, upfront. It could never read what came back and decide to keep digging. A question like find me liquid covered calls to sell has no single API behind it. The orchestra could not do that, and no amount of tuning was going to teach it.

So they made the trade the whole story turns on: they gave up the control the scaffolding gave them, for a system that improves on its own every time the model does. Every layer you don't build is a layer that cannot dilute the model.

ONE TURN message guardrail.in ∥ FAST MODEL · +0 MS model ONE PROMPT · THREE LAYERS toolkit 21 TOOLS · ONE PROTOCOL FILE LOOPS UNTIL THE MODEL STOPS guardrail.out ⊘ BLOCKING · USER FEELS IT answer LINEAR HISTORY · REPLAYED VERBATIM · 98% CACHED DRAWING CORTEX AGENT LOOP SHEET 1 OF 1 REV 0.3 SOURCE RH TECH BLOG · 2026-08-25
Detail A · the same turn, recorded
find me liquid covered calls to sell. how much can i earn?
│guardrail.input ∥ concurrent+0 ms
├portfolioSummary()142 ms
├accountSummary()88 ms
├optionsChain(AAPL, dte≤45)610 ms
├optionsChain(NVDA, dte≤45)588 ms
├duckdb.query(oi > 500 …)31 ms
├widget.optionsTable(rows=6)— void
├guardrail.output ⊘ blocking240 ms
└answer + rendered table1 turn
98% of ~41k input tokens served from prompt cache follow-up tap costs 0 tool calls

This is the question the orchestra could not answer: no single API returns it, and the router grouped its calls once, upfront. The query and the 98% cache-hit rate are Robinhood's published figures; the latencies are illustrative.

The loop stays dumb so the model can be smart. Robinhood Cortex engineering team · on why the scaffolding had to go

The specialists came back — as skills. A name in the prompt, a playbook loaded on demand, nothing orchestrating anything.

04 — The redlines

The limits are the specification.

Most write-ups stop at the feature list. The filed customer agreement is where the real product shape lives, and it is far narrower than the marketing implies. Struck text is what the shipped product cannot do.

Nothing executes without a human tapA pre-filled ticket, then explicit confirmation after reviewing price, quantity, order type and fees.

The most important sentence in the document. Copilot, not autopilot.

No options, futures, or multi-leg ordersIt can read an options chain; it cannot place an options order. Detail A computes a screen it may not execute.

Analysis is permitted where execution is not — a distinction worth copying.

No open internetNo X, no Reddit, no general web. Broker-affiliated sites, investor-relations pages and government sources only, processed statelessly.

A deliberate choice, not an oversight. It is why Cortex can say what it says.

Gaps in coverage, stated plainlyNo comprehensive data for mutual funds, bonds, some closed-end funds, ADRs or penny stocks. iOS only at launch.

Saying the data is unavailable beats returning a confident guess.

Not advice, and not researchInformational only; accuracy unwarranted, no obligation to correct, and the user is solely responsible for verifying everything before acting.

If a surface implies a recommendation, a disclaimer at the bottom does not save it.

05 — The opening

The product is locked. The architecture is not.

Cortex sits behind Robinhood Gold at $5 a month, on iOS only, for US brokerage accounts only — not Android, not web, not Legend, not international, not managed accounts. That is the product. But in August 2026 Robinhood published the thing underneath it in full, and a published architecture belongs to whoever reads it.

What is gated
  • $5 a month, behind Gold
  • iOS only at launch
  • US brokerage accounts only
  • Managed accounts excluded
What is not
  • The loop, published in full
  • The three-layer prompt, with token counts
  • The toolkit and the caching rule
  • The limits, filed as a public agreement

Robinhood wrote the blueprint down.
So everyone can build the Cortex.

The terminal at the top of this page is that implementation, running. Every turn takes the loop drawn in §03 — guardrails, tools, DuckDB, linear history — and orders stop at a ticket, because §04's first redline is enforced in the code rather than in the copy. Back to it ↑

06 — The evidence

Nine exhibits. Six domains.

Every claim on this page traces to something Robinhood published, filed, posted, or serves from a host it controls. Nothing was leaked or inferred. Open the links.

x.com/vladtenevThe CEO, in his own words
robinhood.comNewsroom and engineering blog
cdn.robinhood.comThe filed customer agreement
investors.robinhood.comQuarterly results naming Cortex
agent.robinhood.comA live MCP endpoint
sec.govEDGAR · CIK 0001783879
A
The CEO · the shortest proof there is

Vlad Tenev, on X

x.com/vladtenev/status/1906822311761879535 · 31 March 2025

“Robinhood Cortex, our AI investment tool”

One possessive pronoun, from the founder and CEO, on his own account, five days after the launch event. He lists it as the second of three products announced at The Lost City of Gold — between Robinhood Strategies and Robinhood Banking — and describes it as providing real-time analysis and insights. Nothing else on this page needs to be read for the ownership question to be settled.

Open the post →
B
Engineering · the architecture itself

Robinhood Cortex: The Loop Stays Dumb So the Model Can Be Smart

robinhood.com/us/en/careers/blog/ · 25 August 2026

Three named Robinhood engineers describe building it: Kirill Dubovitskiy, senior engineer on the Cortex Assistant team; Chaofan Wang, staff ML engineer, who led the production deployment of Cortex Digest and Cortex Assistant; Xiaojing Wang, on agent orchestration and evaluations. Every figure on this page marked published — the ten retired agents, the ~25k prompt, the 98% cache-hit rate, the toolkit, tax lots as the first skill — comes from this one post.

Open the post →
C
Legal · binding, and stamped

Robinhood Cortex Assistant Agreement (PDF)

cdn.robinhood.com/assets/robinhood/legal/cortex_agreement.pdf · control number 20260616-5585570-17610501

“owned and offered by Robinhood Markets, Inc.” — §1

A customer agreement served from Robinhood's own CDN, stamped on every page with a control number dating it to 16 June 2026. It assigns the service across four named entities: Robinhood Markets, Inc. owns the technology; Robinhood Financial LLC provides it for securities, Robinhood Derivatives, LLC for futures and event contracts, Robinhood Crypto, LLC for cryptocurrency. Every redline in §04 is quoted from this file.

Open the agreement →
D
Newsroom · the announcement

Introducing Robinhood Strategies, Banking, and Cortex

robinhood.com/us/en/newsroom/ · 27 March 2025

The first appearance of the name, at Robinhood's own Gold keynote, with Digests and Trade Builder as the launch features. On the record from Abhishek Fatehpuria, VP of Brokerage Product.

Open the release →
E
Newsroom · the pivot to execution

Robinhood Presents: YES/NO

robinhood.com/us/en/newsroom/ · 16 December 2025

Cortex reintroduced as a conversational assistant that researches, analyses a portfolio and places trades in plain English, rolling out Q1 2026 to Gold at $5 a month. Framed on the record by Vlad Tenev, Chairman and CEO. The day Cortex stopped being a reader.

Open the release →
F
Newsroom · a second regulator

Digests by Robinhood Cortex launches in the UK

robinhood.com/us/en/newsroom/ · 19 August 2025

Shipped under a second jurisdiction, free to all UK customers — the only market where it has ever been ungated. Attributed to Jordan Sinclair, President of Robinhood UK, and the source of the 95% figure.

Open the release →
G
Newsroom · the advisor channel

Cortex for Advisors, at SYNERGY26

robinhood.com/us/en/newsroom/

Extended to registered investment advisors on TradePMR's Fusion platform at no extra cost. Attributed to Steve Quirk, Chief Brokerage Officer, and carrying the same disclaimer as the consumer product: informational only, not research, not a recommendation.

Open the release →
H
Investor relations · the numbers

Robinhood Reports Second Quarter 2026 Results

investors.robinhood.com · 29 July 2026 · SEC EDGAR CIK 0001783879 · NASDAQ: HOOD

Cortex named in Robinhood's own quarterly reporting: record revenue of $1.31B, Gold subscribers at 4.8 million, ARPU $187. A shareholder release is the highest-consequence place a claim of ownership can appear, and the same filings sit on EDGAR.

Open the release → Open EDGAR →
I
Infrastructure · not the same product

Agentic Trading — agent.robinhood.com/mcp/trading

robinhood.com/us/en/support/articles/ · beta from 27 May 2026

Included because it is routinely mistaken for Cortex. Robinhood runs an MCP server on their own subdomain: read-only across accounts, orders confined to a separately funded agentic account. Cortex is a copilot with a confirmation gate; this is an open door with a spending limit.

Open the support article →

What the exhibits do not show. Robinhood has never named the third-party AI providers behind Cortex — Exhibit C discloses that they exist and names none. No published latency targets, no serving topology, no model identity. Anything beyond these nine documents carries a derived mark, and the latencies in Detail A are illustrative.