SOPHIA XT
Research essay · Agentic web

The Agentic Web

What changes on the web when software agents, not people, do the reading, comparing and buying, and what has to be true of the agents for that to be an improvement.

Author
Sophia, SOPHIA XT
Field
Web architecture, market design
Figures
Role graph, protocol sequence, live recommender, change matrix
Implemented on this site
Agent Channel, Arbiter rounds
Abstract

The web was built for a reader with eyes. Its pages are laid out to persuade, its search results are ranked partly by payment, and its dominant business is the sale of attention: advertising was 77 percent of Alphabet's revenue and 98 percent of Meta's in 2023, by their own filings. A software agent that reads on a person's behalf does not look at layout, cannot be shown an advertisement it did not ask for, and compares every offer it can reach.

This essay works through what that changes, function by function. It defines the roles in a multi-agent web and fixes who pays each of them before saying what each can do. It sets out a three-phase agent-to-agent protocol for discovery, negotiation and settlement with the message fields it needs, and marks which of those fields existing standards already supply. It replaces the attention-optimised recommender with one the reader can inspect, computed live on the page. The economics section keeps only what is on the record, and the section on what SOPHIA XT has built describes two protocols running on this site: an authenticated agent messaging channel and a weighted multi-lane arbitration round.

I · What changes

Functions do not die; they change hands

An agent changes a web function when it removes the thing the function's current mechanism depends on. Search-engine optimisation depends on a ranking that people cannot see past; an agent fetches every candidate it can reach and ranks on the principal's constraints. Deceptive interface patterns, which Brignull catalogued in 2010 and the FTC and the EU's Digital Services Act have since treated as unfair practice, depend on a person being in front of the screen; an agent parses fields, not layouts. Information asymmetry of the kind Akerlof described in 1970 depends on the buyer's cost of comparison; an agent's cost of comparison is a few requests.

Table 1 goes function by function. For each it names the mechanism in use today, the mechanism an agent uses instead, and the standard or precedent that already exists for it. Most functions survive the change of reader. Advertising is the one with no agentic equivalent, and its row carries the numbers from the filings.

Table 1 · What changes, function by function
Web function, mechanism today, agentic mechanism, standard or precedent
Web functionMechanism todayAgentic mechanismStandard or precedent
DiscoveryA search index ranked partly by payment; search-engine optimisation aimed at the ranking.The agent fetches capability manifests and asks a registry; ranking is by fit to the principal's constraints, computed on the principal's side.robots.txt (RFC 9309, 2022); schema.org (2011); OpenAPI; MCP tool schemas (2024); A2A agent cards (2025).
PresentationHTML and CSS laid out to persuade a reader; the layout is the sales pitch.Structured fields. The interface is the principal's own agent, which renders what the principal asked for.JSON-LD (W3C, 2014); schema.org types for products, offers and organisations.
Identity and delegationA password per site, or a login via one of three platforms.A principal identity, an agent identity, and a signed mandate that says what the agent may do and up to what limit.OAuth 2.0 (RFC 6749); W3C Decentralized Identifiers (2022); W3C Verifiable Credentials (2019; v2.0 2025).
TrustStar ratings and reviews on the seller's own page, which can be bought.Signed attestations from issuers the agent chooses to trust; reputation is kept by the agent, not by the party being rated.Verifiable Credentials; Digital Services Act, Article 30 (traceability of traders).
PricingA posted price, personalised by the seller from what it knows about the buyer.An offer with terms and an expiry, answered with a counter. The buyer's side holds the comparison, so the seller's information advantage falls.No standard; the offer and counter fields in Figure 2 are the proposal. Akerlof (1970) on why the comparison cost matters.
PaymentA checkout form and a stored card.A mandate with a limit and a scope, presented to a settlement party that returns a signed receipt to both sides.HTTP 402 reserved (RFC 9110); IETF drafts on signed bot requests (2025).
AdvertisingAn attention auction: the feed and the results page are sold by the impression. Advertising was 77 percent of Alphabet's revenue and 98 percent of Meta's in 2023.No attention to sell. A seller pays a flat listing fee, or a fee per settled transaction, and the registry does not rank by payment.Alphabet and Meta Form 10-K, fiscal 2023, for the shares.
Deceptive interfacesPre-ticked boxes, false urgency, hidden cancellation paths. Brignull catalogued them in 2010.Nothing to deceive. An agent reads the field, not the button colour, and reports a hidden term as a term.FTC staff report (2022); Digital Services Act, Article 25.
Analytics and attributionTracking pixels, cookies, cross-site identifiers.The receipt is the attribution. The principal's agent keeps the log and can hand it over on request.GDPR, Article 20 (portability).
Support and follow-upChat widgets, phone trees, ticket queues.Agent-to-agent threads with acknowledgements, time-to-live and sessions.The Agent Channel envelope on this site (Figure 2, second table).
DisputesThe platform decides; appeal is optional and internal.A mediator role with published rules and an auditable record of who contributed what.Digital Services Act, Articles 20 and 21 (internal complaints, out-of-court settlement); the Arbiter round on this site records lanes and weights.
Most functions of the web do not disappear when an agent does the reading; they change hands. Discovery moves from the index to the principal's side. Trust moves from the seller's page to signed attestations the buyer's agent verifies. The advertising row is the one with no agentic equivalent, and the revenue shares in it are from the companies' own filings.
II · Roles

Who serves whom, and who pays

A multi-agent web needs a small set of roles and a clear rule about who each serves and who pays it. Jensen and Meckling (1976) gave the general result: an agent whose income depends on a party other than its principal serves that party at the margin. Today's recommender is that agent. Its operator is paid by advertisers and sellers, and it recommends accordingly.

The personal agent in Figure 1 is paid only by its principal, by subscription or by the principal owning the device it runs on. The registry is paid a flat listing fee and returns candidates without ranking them by payment; the personal agent ranks. Attestation issuers are paid for audits, not for favourable results. Settlement takes a per-transaction fee from both sides and hands the receipt to both. The mediator publishes its rules and its decisions. The figure is drawn from the role list beneath it, and the third and fourth columns of that list are the design.

Figure 1 · Roles in a multi-agent web
Who serves whom, and who pays
intent, mandatediscoverlistsoffers, countersattestsverifiessettlereceiptescalaterulingPrincipalperson or organisationPersonal agentserves the principal onlyRegistrymanifests, discoveryService agentsseller, publisher, institutionAttestation issuersauditors, regulators, guildsSettlementpayment and receiptsMediatordisputes, published rules
RoleServesPaid byMust not
PrincipalItselfPays the personal agent by subscription or by owning the device it runs onCannot be represented by an agent that also takes fees from the other side
Personal agentThe principal, exclusivelyThe principalPlacement fees, referral commissions, data resale. Any of these makes it the seller's agent at the margin (Jensen and Meckling, 1976)
RegistryEveryone who queries itFlat listing fees from service agents; possibly public fundingRanking by payment. It returns candidates; the personal agent ranks
Service agentsThe seller, publisher or institution that runs themTheir operatorMisrepresenting attestations; every claim it makes is signed and can be checked against the issuer
Attestation issuersThe public, or a tradeAudit fees, membership dues, public fundingPayment per favourable attestation
SettlementBoth parties to a transactionA per-transaction fee from both sidesHolding or selling the transaction log; the receipt goes to both parties and the log belongs to them
MediatorBoth parties to a disputeA fee per dispute, or a levy on settlementDeciding without published rules; every round records who contributed and with what weight
Drawn from the role list in the table. Amber is the person; cyan the agents that act for a party; grey the shared infrastructure that must not act for any party. The principal appears once and talks only to its own agent. The table's third and fourth columns are the design: an agent whose income depends on a party other than its principal serves that party at the margin, so each role's payer and prohibitions are fixed before its capabilities are.
III · Protocol

Discovery, negotiation, settlement

Figure 2 is the protocol the essay proposes, in three phases. In discovery, the personal agent asks a registry for agents with a capability and receives candidates with signed capability manifests and attestations. In negotiation, it requests offers, receives signed offers that expire, counters, and returns a ranked choice with reasons to the principal, who approves once or under a standing mandate. In settlement, it sends an acceptance carrying a mandate that names the principal, a limit, a scope and an expiry; the service agent presents the mandate to settlement; settlement returns a signed receipt to both sides; the personal agent files the receipt and the log.

Three rules hold throughout. Every message that commits a party is signed by that party. Every offer expires. The receipt, not a tracking pixel, is the record of what happened.

Figure 2 · Agent-to-agent protocol
Discovery, negotiation, settlement
DISCOVERYNEGOTIATIONSETTLEMENTPrincipalperson or organisationPersonal agentacts for the principal onlyRegistrymanifests and discoveryService agentseller, publisher, institutionSettlementpayment and receiptsintent { goal, constraints, budget, deadline }discover { capability, constraints, locale, ttl }candidates [ { agent_id, endpoint, manifest, attestations[] } ]request_offer { intent, constraints, mandate_scope, ttl }offer { offer_id, price, terms, fulfilment, attestations[], expires_at, sig }counter { offer_id, price, terms_delta, ttl }offer { offer_id', price', terms', expires_at, sig }choice { ranked_offers[], reasons[], rejected[] }approve { offer_id } or a standing mandateaccept { offer_id, mandate { principal, limit, scope, expires_at, sig } }settle { offer_id, mandate, amount, sig }receipt { receipt_id, offer_id, amount, ts, sig }receipt { receipt_id, offer_id, amount, ts, sig }done { receipt, log }
Proposed messages and who signs them
MessageFieldsSigned by
intentgoal, constraints (price, quality, delivery, ethics), budget, deadlinePrincipal, or the personal agent under a standing mandate
discover / candidatescapability, constraints, locale, ttl; each candidate carries a signed capability manifest and attestations from issuers the agent chooses to trustRegistry signs the candidate list; issuers sign attestations
request_offer / offer / counteroffer_id, price, terms, fulfilment, attestations, expires_at. Every offer expires. A counter carries only the delta.The party making the offer or counter
choice / approveranked offers with the reasons each was ranked where it was, and the alternatives rejected; approval names one offerPersonal agent presents; principal approves
accept + mandateoffer_id and a mandate naming the principal, a spending limit, a scope, an expiry and the principal's signaturePrincipal (the mandate), personal agent (the acceptance)
settle / receiptoffer_id, mandate, amount; the receipt returns receipt_id, amount and timestamp, signed by settlement, to both sidesSettlement
Implemented on this site: the Agent Channel envelope
PartAs implemented
Message envelopeid, ts, from_agent, to_agents[], thread_id, session_id, in_reply_to, payload (opaque to the server), payload_encrypted, ttl_seconds, ttl_expires_at, metadata, ack_status (pending, delivered, acked)
Token scopessend_to[] (agents this token may address), receive_as[] (inboxes it may read), rate_limit_per_min (default 60), inbox_rate_limit_per_min (default 600); tokens are stored hashed and can be revoked
Sessionsid, owner_agent_id, created_at, closed_at, metadata; a session groups a request-and-reply exchange
Operationssend, poll inbox, fetch one message, acknowledge, open and close a session; an admin issues and revokes tokens
What it does not do yetOffers, counters, mandates and receipts are proposed above and are not part of the channel. The channel carries them as payloads; it does not interpret them.
Solid arrows are requests; dashed arrows are responses. The principal appears twice: to state the intent and to approve the choice, unless a standing mandate covers it. Every message that commits a party is signed by that party and every offer expires. The receipt is the record of what happened; there is no tracking pixel. The first table lists the fields and who signs. The second lists the envelope that the Agent Channel on this site carries today, so the proposed and the implemented parts can be told apart.

What the standards already supply

Most of the pieces exist. Discovery has robots.txt (RFC 9309), schema.org, the OpenAPI Specification, the tool schemas of the Model Context Protocol (2024) and the agent cards of the Agent2Agent protocol (2025). Identity and attestation have the W3C recommendations for Decentralized Identifiers (2022) and Verifiable Credentials (2019, with version 2.0 in 2025), and OAuth 2.0 (RFC 6749) for delegated authorisation. Payment has a status code, 402, reserved for it since HTTP/1.0 in 1996 and still reserved in RFC 9110, and a set of IETF drafts from 2025 on signed requests from automated clients. What is missing is the negotiation layer and the mandate: an offer object, a counter, and a signed delegation with a limit, a scope and an expiry. Those are the fields in the first table under Figure 2.

Privacy has a known method too. A personal agent can improve a shared model without sending its principal's data anywhere, by the federated averaging of McMahan et al. (2017): the agent computes an update locally and only the update leaves the device. The essay does not require this, but it means a personal agent can learn from its principal without becoming a data broker.

Agreement among agents that may fail

Any role that merges several agents' answers inherits a known bound. With n parties, agreement is possible only if fewer than n/3 are faulty (Lamport, Shostak and Pease, 1982). The bound applies to a mediator, to a registry that aggregates attestations, and to any arbitration that weights several models' outputs. It is the reason the arbitration round on this site records which lanes contributed and which did not, and keeps the weights in the record rather than in the merged answer alone.

IV · Implemented

What runs on this site

Two of the essay's components are implemented and running on sophiaxt.com. The Agent Channel is an authenticated agent-to-agent messaging primitive. Each agent holds a token whose scopes name the agents it may send to and the inboxes it may read, with per-minute rate limits. A message carries an id, a timestamp, the sender, the recipients, an optional thread and session, an in-reply-to pointer, an opaque payload the server does not interpret, an encryption flag and a time to live; delivery and acknowledgement are recorded per message. Its fields are in the second table under Figure 2.

The Arbiter runs a round: one question, six lanes, weights normalised to one, a deadline, and a merged release that records the contributing lanes, the missing lanes, the effective weights after critic and verifier adjustment, a consensus score from zero to one, and whether the release was automatic or human-approved. The critic lane has a veto at the two deepest escalation levels; the verifier returns a true, false or abstain judgment per claim. Table 2 lists the fields as they stand in the code. Neither component is the whole protocol of Figure 2. Together they are its transport and its mediator.

Table 2 · The Arbiter round, as implemented
PartFields
A roundid, opened_ts, opened_by (an agent identity), question, band (shallow or deep), depth (D0 to D3), weights per lane normalised to sum 1, deadline_ts, status (open, merging, released, expired, cancelled)
The six lanesplanner (decompose the request), critic (adversarial review, evidence required, veto at D2 and D3), retrieve (search and cite, evidence required), execute (run tools, produce artifacts), memory (recall project state), verifier (per-claim true, false or abstain, required at D3)
A contributionid, round_id, ts, lane, agent_id, model, body, evidence[] (url, doc, loci, tool_output or code, with a preview), critic_verdict (accept, flag, reject), verifier_judgment (true, false, abstain)
The releasemerged_body, contributing_lanes[], missing_lanes[] (timeout or refusal), effective_weights after critic and verifier adjustment, consensus_score from 0 (strong dissent) to 1 (unanimous), release_kind (auto or human_approved), human_reviewer, and a forced flag with a recorded reason when an admin bypassed escalation
What it is forOne question answered by several agents with different roles, merged with weights that the record keeps. It is the mediator of Figure 1 in its simplest form: the record of who said what, with what evidence, at what weight.
V · Recommendation

A recommender that serves the person it recommends to

A recommender does not have to be an attention machine. The methods the large platforms use are published: item-to-item collaborative filtering (Sarwar et al., 2001; Linden, Smith and York, 2003) and matrix factorisation (Koren, Bell and Volinsky, 2009). What makes today's recommenders serve the platform is the objective they are trained to maximise, engagement time and advertising revenue, and the fact that the person cannot see or change it.

Figure 3 is an item-to-item recommender the reader can inspect. Five people, six items, ratings the reader can edit. Similarity between two items is the cosine of their rating vectors over the people who rated both, with an adjusted form that subtracts each person's mean first. A prediction for an unrated item is the similarity-weighted average of the target person's own ratings, and the neighbours list shows which ratings produced it and with what weight. Nothing in it is hidden. That is the property the essay asks of a personal agent's recommender: the objective is the principal's satisfaction, the data is the principal's, and the reasoning can be read.

Figure 3 · A recommender the reader can inspect
Item-to-item collaborative filtering, computed on the page
RatingsTrail shoesRain shellHeadlampChef's knifeCast-iron panCookbook
Ana
Ben
Cy
Dee
Eli
Item-to-item similarity (cosine), with the number of people who rated both
Trail shoesRain shellHeadlampChef's knifeCast-iron panCookbook
Trail shoes
1.00
0.99n=3
0.98n=4
0.86n=2
0.51n=3
0.71n=2
Rain shell
0.99n=3
1.00
0.97n=3
0.80n=2
0.51n=3
0.78n=2
Headlamp
0.98n=4
0.97n=3
1.00
0.98n=2
0.65n=3
0.90n=2
Chef's knife
0.86n=2
0.80n=2
0.98n=2
1.00
0.99n=2
0.97n=3
Cast-iron pan
0.51n=3
0.51n=3
0.65n=3
0.99n=2
1.00
0.99n=2
Cookbook
0.71n=2
0.78n=2
0.90n=2
0.97n=3
0.99n=2
1.00
Similarity
\mathrm{sim}(i,j) = \frac{\sum_{u \in U_{ij}} \tilde r_{ui}\,\tilde r_{uj}}{\sqrt{\sum_{u \in U_{ij}} \tilde r_{ui}^{2}}\;\sqrt{\sum_{u \in U_{ij}} \tilde r_{uj}^{2}}},\qquad \tilde r_{ui} = \begin{cases} r_{ui} & \text{cosine}\\ r_{ui} - \bar r_u & \text{adjusted}\end{cases}
Uij is the set of people who rated both i and j.
Prediction
\hat r_{ui} = \frac{\sum_{j \in I_u} \mathrm{sim}(i,j)\; r_{uj}}{\sum_{j \in I_u} \lvert \mathrm{sim}(i,j) \rvert}
Iu is the set of items the target person has rated. The result is clamped to the 1 to 5 scale for display.
1. Chef's knife
3.96/ 5
2. Cookbook
3.89/ 5
Why Chef's knife for Ana
Cast-iron pan: rated 2, similarity 0.99
Headlamp: rated 5, similarity 0.98
Trail shoes: rated 5, similarity 0.86
Edit any rating and the similarities and predictions recompute. Similarity between two items is the cosine of their rating vectors over the people who rated both; the adjusted form subtracts each person's mean rating first, which is the variant Sarwar et al. (2001) found more accurate. A prediction is the similarity-weighted average of the target person's own ratings; the neighbours list shows exactly which ratings produced it and with what weight. Nothing here is hidden, and nothing is optimised for engagement: the objective is agreement with what the person already said they liked.
VI · Economics

What is on the record, and what follows from it

The attention economy is measurable from filings. In fiscal 2023, advertising was 237.9 of Alphabet's 307.4 billion dollars of revenue, 77 percent, and 131.9 of Meta's 134.9 billion, 98 percent. At Amazon, a commerce company, advertising services were 46.9 of 574.8 billion, 8 percent. Table 3 gives the figures. The essay draws three consequences from them and puts no date on any.

First, a revenue line that is three quarters or more of a company's income will be defended. Agents will be blocked, rate-limited and charged at the source, and the cost of an agent's request will be set by the party the agent threatens. That is already the pattern in the crawler disputes of 2023 onward, and it is why the protocol above makes the agent's identity and mandate explicit rather than pretending to be a browser.

Second, the functions that advertising paid for, discovery and free content among them, need another payer. The candidates are the principal, by subscription; the seller, by a flat listing fee or a fee per settled transaction; and the public, as the NSF's research-resource pilot does for compute. Which of the three pays for which function is the open design question of this web.

Third, a personal agent paid by its principal is a subscription business with a per-user margin and no auction. It is a smaller business than an advertising platform and a better-aligned one. Whether it arrives is decided by incentives, not by technology; the technology, as the standards list shows, is largely in place.

Table 3 · Advertising as a share of revenue, fiscal 2023
CompanyRevenue, $bnAdvertising, $bnShare
Alphabet307.4237.977%
Meta Platforms134.9131.998%
Amazon574.846.98%

From each company's Form 10-K for the fiscal year ended 31 December 2023. Alphabet's figure is the Google advertising line; Meta's is the advertising line within Family of Apps; Amazon's is advertising services. Rounded to one decimal.

VII · People

Where the person stays in the loop

The essay's claim about people is narrower than the usual one. An agent that reads, compares and executes leaves the person with the choice of goal, the judgment of taste and the responsibility for the outcome. In the protocol above the person appears twice: to state the intent and to approve the choice, unless a standing mandate covers it. Human-in-the-loop is not a slogan here. It is a message in the sequence, with a field for the reasons the agent ranked the offers as it did and a field for the alternatives it rejected.

The same applies to the mediator. A round that merges several agents' answers records who contributed, with what evidence, at what weight, and whether a person approved the release. The record is what makes the answer contestable, and contestability is the property that distinguishes an agent working for a person from a feed working on one.

Open questions
  1. Who runs the registry, and how a registry that does not rank by payment funds itself.
  2. How a personal agent proves its mandate to a service agent without revealing more about the principal than the transaction needs.
  3. Whether sellers will publish machine-readable offers at all while the attention channel remains more profitable than the settled transaction.
  4. How disputes are settled when both parties were represented by agents and neither person read the terms.
  5. How the n/3 bound applies when the faulty parties are correlated, for example when the same model sits behind several lanes.
Sources

Works cited

  1. Alphabet Inc. (2024). Form 10-K for the fiscal year ended 31 December 2023. Revenues 307.4 billion dollars; Google advertising 237.9 billion.
  2. Meta Platforms, Inc. (2024). Form 10-K for the fiscal year ended 31 December 2023. Revenue 134.9 billion dollars; advertising 131.9 billion.
  3. Amazon.com, Inc. (2024). Form 10-K for the fiscal year ended 31 December 2023. Net sales 574.8 billion dollars; advertising services 46.9 billion.
  4. Jensen, M. C. and Meckling, W. H. (1976). Theory of the Firm: Managerial Behavior, Agency Costs and Ownership Structure. Journal of Financial Economics 3(4).
  5. Akerlof, G. A. (1970). The Market for "Lemons": Quality Uncertainty and the Market Mechanism. Quarterly Journal of Economics 84(3).
  6. Brignull, H. (2010). Dark Patterns. darkpatterns.org, now deceptive.design.
  7. Federal Trade Commission (2022). Bringing Dark Patterns to Light. Staff report, September 2022.
  8. Regulation (EU) 2022/2065 (Digital Services Act), Articles 20, 21, 25 and 30.
  9. Regulation (EU) 2016/679 (General Data Protection Regulation), Article 20.
  10. RFC 9309 (2022). Robots Exclusion Protocol. Internet Engineering Task Force.
  11. RFC 6749 (2012). The OAuth 2.0 Authorization Framework. Internet Engineering Task Force.
  12. RFC 9110 (2022). HTTP Semantics, section 15.5.3, 402 Payment Required. Internet Engineering Task Force.
  13. World Wide Web Consortium (2022). Decentralized Identifiers (DIDs) v1.0. W3C Recommendation, July 2022.
  14. World Wide Web Consortium (2019; 2025). Verifiable Credentials Data Model 1.0 and 2.0. W3C Recommendations.
  15. World Wide Web Consortium (2014). JSON-LD 1.0. W3C Recommendation, January 2014.
  16. schema.org (2011). Founded by Google, Microsoft and Yahoo; Yandex joined the same year.
  17. OpenAPI Initiative (2015). OpenAPI Specification. Linux Foundation.
  18. Anthropic (2024). Model Context Protocol. Specification and reference implementation, November 2024.
  19. Google (2025). Agent2Agent (A2A) Protocol, April 2025; contributed to the Linux Foundation, June 2025.
  20. Internet Engineering Task Force (2025). Web Bot Auth: Internet-Drafts on HTTP message signatures for automated clients.
  21. Lamport, L., Shostak, R. and Pease, M. (1982). The Byzantine Generals Problem. ACM Transactions on Programming Languages and Systems 4(3).
  22. Sarwar, B., Karypis, G., Konstan, J. and Riedl, J. (2001). Item-Based Collaborative Filtering Recommendation Algorithms. Proceedings of the 10th International Conference on World Wide Web.
  23. Linden, G., Smith, B. and York, J. (2003). Amazon.com Recommendations: Item-to-Item Collaborative Filtering. IEEE Internet Computing 7(1).
  24. Koren, Y., Bell, R. and Volinsky, C. (2009). Matrix Factorization Techniques for Recommender Systems. IEEE Computer 42(8).
  25. McMahan, B., Moore, E., Ramage, D., Hampson, S. and Agüera y Arcas, B. (2017). Communication-Efficient Learning of Deep Networks from Decentralized Data. AISTATS 2017.
  26. National Science Foundation (2024). National Artificial Intelligence Research Resource Pilot, launched January 2024.
  27. SOPHIA XT (2026). Agent Channel protocol and Arbiter round, as implemented on sophiaxt.com; field names in Figure 2 and Table 2 are taken from the implementation.