Diagnose third-party sales agents

When your storefront uses a third-party AdCP-compatible sales agent as an inventory source, Interchange can help you answer two different questions:

Is the source set up correctly? Check source status, credentials, advertised capabilities, and compliance.
What happened on recent buyer traffic? Inspect recent AdCP calls, responses, task statuses, and failures for that source.

Use both. A source can be configured correctly but still fail a specific buyer request, and a failed buyer request can come from a valid business rejection rather than a broken connection. Diagnostics keep three evidence types separate:

A source test is an explicit sandbox test against the selected source.
A source call is an observed protocol exchange with the selected source, such as get_capabilities or a passthrough get_products request.
A storefront buyer-path or composition run describes work at the storefront layer. It is not evidence that the selected source was called unless a source exchange is attached to it.

This distinction matters for no_ingredients: a composition run can stop at the storefront before it calls the external sales agent. That failure must not be shown as a failed source call or source test. In ordinary passthrough mode, the storefront sends the brief to the external agent’s get_products; that call uses the agent’s finished products and does not require ingredients. For external sales-agent sources, also separate live source health from component-cache health. Live health answers whether passthrough discovery or media-buy calls reached the source and completed. Component-cache health answers whether Interchange can read the source’s raw products/components for merchandising without calling the source during buyer-request composition. Cache complaints usually mean the source does not support a usable component response, returned invalid/missing product metadata, has an errored or cold cache state, or cannot refresh because of auth or reachability. Stale-but-usable cached rows are not automatically a failure; they are valid composition inputs when the storefront allows hard-stale OK cache reads. Soft-refresh age is handled automatically by Interchange’s stale-while-revalidate cache path; it does not create a seller action item. A cache complaint does not by itself mean live passthrough is down. Interchange does not make wholesale product or signal catalog requests to every external sales agent. For third-party sales-agent sources, those catalog requests run only when product composition is on for the storefront and the source reports AdCP 3.1+ support. If product composition is off, diagnostics treat the source as pass-through and focus on live buyer-request activity instead of component-cache readiness. When paid composition is enabled, only the source’s AdCP 3.1+ wholesale products are composition inputs; its ordinary finished products are not reclassified as ingredients. Active managed ad-server sources force composition because their raw inventory must be turned into products. When a seller-operated source stays unhealthy long enough to trigger a proactive Murph alert, the alert links directly to this diagnostics surface with the affected source selected. Open that link first, then use the recent activity and developer handoff sections for the partner-safe debug ID, task ID, operation ID, and correlation headers behind the failing calls.

Endpoint

GET /api/v2/storefront/inventory-sources/{sourceId}/diagnostics Returns seller-facing diagnostics for one third-party sales-agent or modular inventory source. The response combines the current source setup, recent AdCP activity, test-run evidence, latency rollups, error rates, discovery participation, demand impact, and developer handoff identifiers. New outbound calls include a partner-safe x-scope3-debug-id that also appears in the diagnostics handoff. To run a direct source test, use the shared storefront operation run_inventory_source_discovery_test, backed by: POST /api/v2/storefront/inventory-sources/{sourceId}/tests/discovery This source-scoped operation calls the selected external sales agent’s get_products with a read-only brief. It creates no media buy, spends nothing, and does not test reporting or webhooks. Its outcome, product count, step, and available debug identifiers are recorded as a durable source test run, so the result remains available from list_agent_test_runs and in Source Diagnostics. MCP hosts open the same Source Diagnostics app through the typed open_source_diagnostics tool. The widget and its actions use shared MCP contracts rather than sending a new chat message to Murph.

Request

curl "https://api.interchange.io/api/v2/storefront/inventory-sources/retail-adcp/diagnostics?windowHours=24" \
  -H "Authorization: Bearer $SCOPE3_API_KEY"

curl -X POST "https://api.interchange.io/api/v2/storefront/inventory-sources/retail-adcp/tests/discovery" \
  -H "Authorization: Bearer $SCOPE3_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"brief":"Return representative products available to a US buyer."}'

Parameters

Field	Type	Required	Notes
`sourceId`	string (path)	Yes	Storefront-scoped inventory source ID.
`windowHours`	integer (query)	No	Lookback window for activity and test-run rollups. Defaults to the service window, minimum `1`, maximum `720` (30 days).

Response

{
  "source": {
    "id": "42",
    "sourceId": "retail-adcp",
    "name": "Retail AdCP Agent",
    "executionType": "AGENT",
    "status": "ACTIVE",
    "agentId": "agent_retail",
    "endpointUrl": "https://sales-agent.example.com/mcp",
    "protocol": "MCP",
    "auth": {
      "type": "bearer",
      "required": true,
      "configured": true
    },
    "capabilities": {
      "tools": ["get_products", "create_media_buy"],
      "products": "supported",
      "createMediaBuy": "supported",
      "updateMediaBuy": "unknown",
      "signals": "unsupported"
    },
    "health": {
      "status": "healthy",
      "lastError": null,
      "lastErrorCode": null,
      "lastErrorAt": null,
      "lastSuccessAt": "2026-06-18T12:45:00Z",
      "lastCheckedAt": "2026-06-18T12:50:00Z"
    }
  },
  "window": {
    "hours": 24,
    "startedAt": "2026-06-17T13:00:00Z",
    "endedAt": "2026-06-18T13:00:00Z",
    "sampledActivityCount": 37,
    "activityTruncated": false,
    "sampledTestRunCount": 4
  },
  "performance": {
    "requestCount": 18,
    "responseCount": 18,
    "exchangeCount": 18,
    "completedCount": 15,
    "failedCount": 1,
    "inputRequiredCount": 1,
    "pendingCount": 1,
    "rejectedCount": 0,
    "timeoutCount": 0,
    "timeoutRate": 0,
    "errorRate": 0.06,
    "inputRequiredRate": 0.06,
    "completedRate": 0.83,
    "latencyStatus": "within_threshold",
    "latencyThresholdMs": 30000,
    "overThresholdCount": 0,
    "staleAsyncResponseCount": 0,
    "p50LatencyMs": 1200,
    "p95LatencyMs": 4200,
    "p99LatencyMs": 4200,
    "unknownLatencyCount": 0
  },
  "comparison": {
    "previousWindow": {
      "startedAt": "2026-06-16T13:00:00Z",
      "endedAt": "2026-06-17T13:00:00Z",
      "exchangeCount": 14,
      "issueCount": 0,
      "timeoutCount": 0,
      "errorRate": 0,
      "p95LatencyMs": 3100,
      "sampledActivityCount": 28,
      "activityTruncated": false
    },
    "issueDelta": 2,
    "timeoutDelta": 0,
    "errorRateDelta": 0.06,
    "p95LatencyDeltaMs": 1100,
    "trend": "new_issue",
    "summary": "New issue pattern in this window: 2 more affected requests."
  },
  "toolBreakdown": [
    {
      "tool": "get_products",
      "exchangeCount": 12,
      "completedCount": 11,
      "failedCount": 1,
      "inputRequiredCount": 0,
      "rejectedCount": 0,
      "timeoutCount": 0,
      "p95LatencyMs": 3600
    }
  ],
  "discoveryParticipation": {
    "calledCount": 12,
    "skippedCount": 0,
    "excludedCount": 0,
    "timedOutCount": 0,
    "skipReasons": []
  },
  "outcomeMix": {
    "returnedProductsCount": 10,
    "returnedNoProductsCount": 1,
    "failedCount": 1,
    "businessRejectedCount": 0,
    "pendingCount": 1,
    "inputRequiredCount": 1,
    "timedOutCount": 0,
    "skippedCount": 0
  },
  "demandImpact": {
    "buyerRequestsAffected": 2,
    "missedProductOpportunityCount": null,
    "notes": [
      "Affected request count includes failed, timed-out, rejected, input-required, and skipped diagnostic attempts in this window.",
      "Missed product opportunity count is not estimated until buyer-side debug demand captures expected product counts."
    ]
  },
  "recentActivity": [
    {
      "id": 98765,
      "timestamp": "2026-06-18T12:45:00Z",
      "tool": "get_products",
      "taskStatus": "COMPLETED",
      "activityType": "response",
      "taskId": "task_123",
      "operationId": "op_456",
      "contextId": "ctx_789",
      "idempotencyKey": "idem_abc",
      "correlationId": "trace_def",
      "initiatorEmail": "s***@example.com",
      "origin": {
        "kind": "live_demand",
        "testRunUid": null,
        "testRunStatus": null,
        "testRunToolName": null,
        "testRunCreatedAt": null
      },
      "isIssue": false,
      "summary": "Returned 5 products."
    }
  ],
  "diagnosis": {
    "severity": "ok",
    "owner": "seller",
    "topCause": "Source is responding within threshold.",
    "issues": [],
    "nextSteps": ["Continue monitoring failed calls and webhook completion."],
    "developerHandoff": {
      "sourceId": "retail-adcp",
      "sourceName": "Retail AdCP Agent",
      "agentId": "agent_retail",
      "endpointUrl": "https://sales-agent.example.com/mcp",
      "latestTaskId": "task_123",
      "latestOperationId": "op_456",
      "latestContextId": "ctx_789",
      "latestIdempotencyKey": "idem_abc",
      "latestCorrelationId": "trace_def",
      "correlationHeaders": {
        "x-scope3-trace-id": "trace_def"
      },
      "latestError": null
    }
  },
  "docs": [
    {
      "label": "Inventory sources",
      "url": "https://docs.interchange.io/v2/storefront/inventory-sources/overview"
    }
  ]
}

The most important response blocks are:

Field	What it tells you
`source`	Current setup state: source identity, status, endpoint, auth, advertised capabilities, and latest health.
`window`	The lookback period and how much activity/test-run evidence was sampled. `activityTruncated: true` means the 200-row sample cap was reached; `recentActivity[]` shows only the most recent 200 rows, so counts and rates reflect the sample rather than the full window.
`performance`	Sampled `get_products` request/response counts, completion/failure/input-required rates, timeout rate, latency percentiles, and whether latency exceeded the configured threshold.
`comparison`	Current lookback window compared with the immediately preceding equal-length window. Trends are `new_issue`, `worse`, `improved`, `recovered`, `unchanged`, or `not_enough_data`; they describe observed source activity only. Previous-window `sampledActivityCount` and `activityTruncated` use the same 200-row sample cap as the current window.
`toolBreakdown[]`	Per-tool outcomes across sampled source-diagnostic exchanges. The current seller-facing diagnostic window analyzes `get_products`; use `externalCallLanes[]` for other observed outbound operations.
`externalCallLanes[]`	Prometheus-backed outbound-call rollups for this exact inventory source. Each lane reports call count, outcomes, and p95 latency without exposing other sources or fleet targets. A newly deployed source label can have no observations yet.
`discoveryParticipation`	Observed `get_products` exchanges with this source, plus source-scoped diagnostic skips and timeouts. This is source-call evidence, not the buyer-side storefront candidate set.
`outcomeMix`	Whether calls returned products, returned no products, failed, timed out, waited for input, or were business-rejected.
`demandImpact`	Affected request count plus notes. Missed product opportunity count is currently `null` until buyer-side debug demand captures expected product counts.
`recentActivity[]`	Most recent `get_products` calls, responses, task statuses, errors, trace/correlation identifiers, initiator email, sandbox-test/live-demand origin, and summaries.
`diagnosis`	Severity, owner, top cause, structured `issues[]` breakdown, next steps, and developer handoff details to share with the source operator.

diagnosis.owner tells you who must act:

seller — a generic external sales agent you operate, or an adapter whose credentials need re-authorizing. The topCause and nextSteps are addressed to you.
scope3 — an official Scope3-hosted adapter (Pinterest, Reddit, Snap, …) whose runtime is failing. Scope3 operates that runtime; the failure is ours to fix and recovers automatically, so there is nothing for you to do. nextSteps will say so rather than asking you to debug our infrastructure.

diagnosis.topCause is the primary explanation to show first. Use diagnosis.issues[] when more than one signal is present in the same window: for example stale async callbacks, caller-deadline timeouts, slow responses, non-timeout failures, input-required responses, business rejections, skipped diagnostic attempts, missing auth, or inactive sources. Each issue includes a stable mode, severity, affected count, and human-readable summary. Issue mode values use the same source failure vocabulary as the diagnosis model, such as stale_async, timeout_degraded, auth_missing, source_runtime_error, business_rejected, and input_required. comparison.trend is a quick movement signal, not an uptime or SLA claim. It compares sampled source activity in the requested window with the immediately previous window of the same length. not_enough_data means neither window has enough source activity to compare; latency remains unknown when request and response rows cannot be paired. The latest source-health check can be older than the selected activity window. When an older failed check has no newer traffic to confirm or clear it, the overview labels it as stale evidence and asks for current verification. It does not claim the source is currently down, and it does not say that no action is needed. When the selected window has newer protocol exchanges and no observed failures, that activity supersedes an older failed health record in the current diagnosis.

Errors

400 BAD_REQUEST — windowHours is not a positive integer or is greater than 720.
401 UNAUTHORIZED — missing or invalid API key.
404 NOT_FOUND — no inventory source with this sourceId exists for the storefront.

See Errors for the full error contract.

Open the diagnostics surface

Source diagnostics overview showing a sales-agent source that needs attention, error counts, late callbacks, and the next investigation action

Diagnostics open from the source you are looking at, scoped to that source:

From the source itself. In the ad-server or sales-agent source app in chat, use Open full diagnostics. It opens the Source Diagnostics app already focused on the connection you had selected. (The in-app View details / View diagnostics buttons are different — they switch to the advanced tab inside the same source app.)
From Pending operations. When a source you operate degrades, it appears in the Sources degraded group of the Pending operations view with its severity and a one-line summary. Each row’s Open full diagnostics opens the Source Diagnostics app scoped to that source.
By asking Murph. Ask “why is <source> failing?” or “show me diagnostics for <source>” — Murph opens the Source Diagnostics app scoped to that source. Naming the source focuses the app on it; otherwise it opens on the source you last had selected.
From the Help menu. Open Ask Murph, choose Help, then choose Diagnostics for the storefront-wide diagnostics view (change history, debug calls, source tools, test runs).

Choose Show me from a Source Diagnostics announcement, or choose ? in the diagnostics surface, to start the two-minute quick tour. The tour teaches the same operating sequence in every supported chat host:

Start with the question: is this source healthy, what changed, and who acts?
Choose the evidence window. Start with 24 hours, narrow for an active incident, or widen it to confirm a pattern.
Read the overview verdict before inspecting individual calls.
Use Evidence for recent calls and partner-safe handoff identifiers.
Take the smallest diagnosed next action, then refresh or run a focused test.

The surface has three primary views: Summary, Evidence, and Setup. Run discovery test calls the selected external source’s get_products directly with a read-only, no-spend brief and records the result as a durable source test run. It does not create a media buy. Refresh capabilities is the secondary setup check: it calls the source capability endpoint directly and shows the result in the app; it does not send a synthetic question to Murph. Capability refresh verifies endpoint reachability, credentials, and declared tools only—it does not prove discovery. A buyer-path result appears under the selected source only when diagnostics have an observed source exchange to attribute to it. A storefront intelligence run that stopped before source dispatch remains storefront evidence, not a failed call against the external agent. In Setup, a complete third-party sales agent is shown as pass-through by default. If composition is locked on, the storefront still has an active managed ad-server source; that source is named in the app because it—not the selected third-party agent—is what requires composition. Deactivate the managed source before switching to pass-through. Product composition for a third-party agent is an optional paid add-on. For a pass-through source, Connected means its source connection and required credentials are ready. Setup does not wait for an Interchange wholesale catalog, and an unobserved reporting status does not become setup work. A subsequently observed degraded or unhealthy source is shown as Needs attention instead. The tour changes tabs and highlights controls, but it does not change source configuration. Any product action keeps its normal safeguards. You can also open Source Diagnostics directly by replacing <account-id> with your account id:

https://interchange.io/<account-id>/murph?view=chat&askMurph=open_feature&feature=source-health

To focus the app on one inventory source, include diagnosticsSourceId:

https://interchange.io/<account-id>/murph?view=chat&askMurph=open_feature&feature=source-health&diagnosticsSourceId=<source-id>

Task-level filtering is available inside the app’s recent-call search after it loads; there is not currently a task-id deep link. Slack cannot render the MCP app inline. When Murph diagnoses a sales-agent source from Slack, it provides this same account- and source-scoped link as a Open sales-agent diagnostics button. Open it, choose Run discovery test, then reply done in the Slack thread. Murph looks up the recorded source test and interprets it; you do not need to copy the result between apps.

Start with the inventory source

Open the storefront inventory source in the app, or call Get storefront readiness. The sourceDiagnostics[] entry for each source gives the current operating picture:

Field	What it tells you
`sourceStatus`	Whether the source is active, pending, or disabled.
`auth`	Whether the source requires credentials and whether they are configured.
`capabilities`	Whether the source advertises support for product discovery, media-buy creation, updates, signals, and wholesale products.
`productBuilder`	Whether the source is classified for `composition`, `passthrough`, or `unknown`; use `wholesaleProductCount`, `signalCount`, `catalogCacheCold`, and `declaredUnsupportedIngredients` to interpret component-cache readiness. For third-party sales-agent sources, component-cache readiness is evaluated only when product composition is on and the source reports AdCP 3.1+ support.
`compliance`	Latest AAO / AdCP compliance result for the source.
`debug`	Sanitized advertised tools, channels, publisher domains, protocol version, billing support, and related capability metadata.
`health`	Current source health, including latest error, latest success, and latest check timestamps when available.

If the source is not active, credentials are missing, or the source does not advertise the tool you need, fix that before debugging individual buyer requests.

Inspect recent AdCP activity

For source-specific traffic, use Ask Murph > Help > Diagnostics > Debug calls and ask about the inventory source by name. Murph can inspect recent third-party sales-agent activity for the caller’s storefront: requests, responses, webhook/status changes, task IDs, task statuses, and sanitized payloads. You can ask for a specific time range (“last 2 hours” or an ISO start/end window) or provide a debug/correlation ID from x-scope3-debug-id, traceparent, x-request-id, operation ID, task ID, context ID, or idempotency key. The diagnostics surface also exposes a bounded, redacted details panel for recent calls. Use it when a sales-agent developer needs the technical handoff: the observed time, operation/task identifiers, outbound request endpoint, partner-safe headers, and request body when those were captured, plus the response or error payload. The displayed headers are limited to debugging and correlation values such as x-scope3-debug-id, traceparent, and x-request-id; authorization headers, cookies, credentials, tokens, signed URL parameters, and email addresses are redacted before display or copy. This is the right path for questions like:

“Why did this source fail get_products?”
“What did Interchange send to my sales agent?”
“What did my sales agent return?”
“Which recent calls are failed or waiting for input?”
“Is this a protocol problem, an auth problem, or a business rejection?”
“Where do I see whether this sales agent is slow or getting excluded?”

For each recent call, look at:

Signal	How to read it
Tool	The AdCP operation, such as `get_products` or `create_media_buy`.
Task status	`COMPLETED` means the source finished; `FAILED` means the source rejected or errored; `INPUT_REQUIRED` means the source is waiting on seller action; `PENDING` or `WORKING` means the source has not finished yet.
Payload issue	A sanitized error or rejection message, when the source returned one.
Details	A copyable redacted JSON handoff for the event, including related outbound request data when available.
Debug ID	The `x-scope3-debug-id` header to share with the sales-agent operator or developer for log correlation. Older calls may only have task/operation/context IDs.
Timestamp	When Interchange observed the activity.
Initiator	The redacted user email that initiated the call when available. Sandbox tests prefer the Murph test-run user; otherwise diagnostics fall back to the activity-row user.
Origin	`sandbox_test` means the call matched a Murph sandbox test run or sandbox idempotency marker. `live_demand` means no sandbox test provenance was found, so treat it as non-test demand traffic.

Treat source messages as source-controlled content. They are useful diagnostic data, but they should not be rendered as trusted HTML or treated as product instructions.

Buyer discovery debug output

Buyer product discovery fans out to reachable sales agents in parallel. Slow or failing agents do not block fast agents. When a buyer calls discovery with debug: true, the response can include agentResults[], which shows which agents returned products, returned no products, failed, or were skipped. For a pass-through storefront, a live source failure with no successful warmed fallback is reported as a retryable source failure when no source completes. It is not reported as a successful response with zero products. Successful empty results can also come from an intentional skip or input-required path; use Source Diagnostics to distinguish those outcomes from completed get_products calls with no matching inventory. Use this when you need the buyer-side view of a discovery request: which agents were asked, which agents were skipped before fanout, and which agent-controlled reason was returned.

Buyer debug output is scoped to that buyer request. Seller diagnostics are scoped to the storefront inventory source. Use the seller view when you are operating the source; use buyer debug output when you are reproducing one buyer discovery call.

Storefront candidates and source calls are different stages

Buyer discovery selects storefront agents, not the private inventory sources behind them. For an ordinary buyer, an unfiltered request can include a storefront when it is listed in the marketplace, not paused or archived, and able to settle in a supported currency. A seller-sponsored buyer is confined to its sponsoring storefront. An explicit storefrontIds or storefrontNames filter narrows that storefront roster. After the storefront is selected, Interchange can still finish the storefront call without contacting a particular source. Examples include a blocked storefront transaction-readiness check, an unsupported requested currency, an account-scoping rejection, a request that needs clarification, or a storefront that serves a cached or composed catalog. Only a source-attributed get_products exchange proves that the source itself was called. For a readiness block, use the failing check’s guidance object as the canonical explanation. It names why the check failed, where it stops the buyer path, the exact fix, implicated sources, and typed evidence when available. This means an all-zero discoveryParticipation block does not prove that no buyer demand existed, and it does not prove that the storefront was absent from every candidate set. It means diagnostics observed no attributable source call or source-test skip in that window. To answer whether a storefront participated in a particular buyer request, use that request’s agentResults[] with debug: true. If the original buyer request is unavailable, Scope3 support can correlate the storefront’s buyer-path records with source activity. Two setup fields are commonly misread as routing gates:

Empty storefront-card regions or channels do not by themselves remove a storefront from get_products fanout. Requested-channel prefiltering uses the agent’s advertised channel capabilities; unknown coverage remains eligible. Country constraints are passed in the brief for the storefront or source to evaluate.
linkedStorefront on an inventory-source response is retained for response compatibility and is always null. It does not attach an AGENT source to its owning storefront and is not a discovery-routing requirement.

Empty responses and latency do not change future ranking

returnedNoProductsCount and latencyStatus are diagnostic observations. They are not inputs to later storefront eligibility, source selection, or product and proposal ranking. There is no rolling empty-response or slow-response penalty window. A source that returns no products contributes no candidates to that individual response, so there is nothing from that source to rank for that request. When a buyer explicitly enables managed screening and ranking, Interchange evaluates the products and proposals returned for the current request against the buyer’s instructions. Without that requested ranking, Interchange does not apply a historical-performance ranking system.

How source latency is measured

The latency fields and a source-test run’s durationMs measure different intervals:

Each diagnostics latency sample is one attributable get_products exchange, measured from its recorded request activity to its final recorded response activity. p50LatencyMs, p95LatencyMs, and p99LatencyMs are percentiles across those paired samples in the selected window.
latencyStatus is over_threshold when any paired exchange is greater than latencyThresholdMs, or when the window contains a timeout. It is not a comparison between the window’s p95 and the threshold. When no recorded exchange supplies an explicit timeout or deadline, the current diagnostic default is 5,000 ms.
A direct source test’s durationMs is wall-clock time for the complete test probe, from source-client setup through completion or failure of get_products. It can include connection/session setup, capability negotiation performed by the client, the get_products exchange, and asynchronous-task handling. It is calculated before trace lookup and test-run persistence. Separate capability calls do not enter the get_products latency percentile, even though they can increase the test’s total duration.

Use the source exchange and transport timeline to split seller-handler time from Interchange/client overhead. Do not compare the run’s total durationMs directly with latencyThresholdMs.

What this does not answer yet

The diagnostics show source state, recent protocol activity, latency percentiles, timeout counts, and source-level skipped/excluded evidence for the selected lookback window. For broader business impact analysis, combine:

sourceDiagnostics[].health for the latest known source health.
Murph diagnostics for recent ADCP call details.
Buyer discovery agentResults[] with debug: true for one discovery request.

If a seller asks for missed product opportunities, lost buyer demand, revenue impact, or longer-term trends, treat that as a product/documentation gap unless a tool returns that exact rollup. The actionable answer should explain what exists today, link to the UI surface above, and call out the missing diagnostic that should be added.

Empty catalog from a version mismatch (`VERSION_UNSUPPORTED`)

If a source’s products vanish from your catalog and its recent debug calls show a VERSION_UNSUPPORTED payload — e.g. AdCP version '3.1' is not supported. Supported: ['3.0', ...] — the source’s AdCP server is rejecting the protocol version Interchange pins instead of serving a compatible one. This is almost always a source-side issue, not a problem with your storefront. Per the AdCP spec, a source that supports the same major version must downshift to its highest supported release and serve the request; VERSION_UNSUPPORTED is reserved for a genuine cross-major mismatch. A source that returns it for a same-major minor (it supports 3.0 but rejects 3.1) is running a non-conformant or stale AdCP server build. Interchange retries once at a compatible version as a safety net, but if the source can’t serve any version Interchange speaks, its products stay absent until the source operator upgrades their AdCP server. Share the source name and the sanitized VERSION_UNSUPPORTED payload (from the Debug calls tab, Details panel) with the sales-agent operator, and point them at AdCP versioning & negotiation for the rule their server must follow.

Practical checklist

When a source is not showing up or a buyer request did not return products:

Confirm the inventory source is active.
Confirm credentials are configured if the source requires auth.
Confirm the source advertises the needed capability, especially get_products for product discovery.
Check source health for the latest error, success, and check timestamps.
Ask Murph to inspect recent debug calls for that source.
If reproducing a buyer discovery request, run discovery with debug: true and inspect agentResults[].
If the failure is still unclear, share the source name, task ID, timestamp, and sanitized error with your sales-agent operator or Scope3 support.

Inventory sources

Get storefront readiness

Inspect readiness and per-source diagnostics

Product discovery

Understand buyer discovery and agentResults

Errors

Shared Interchange error contract

AdCP versioning & negotiation

Why a version mismatch empties a catalog, and the downshift rule

Getting Started

Operating Your Storefront

Inventory Sources

Real-Time Targeting (TMP)

Approvals & Reviews

Buyer Onboarding

Demand & Signals

Proposals & Agents

Buyer Routing

Analytics & Activity

Billing

Account

Diagnose third-party sales agents

Endpoint

Request

Parameters

Response

Errors

Open the diagnostics surface

Start with the inventory source

Inspect recent AdCP activity

Buyer discovery debug output

Storefront candidates and source calls are different stages

Empty responses and latency do not change future ranking

How source latency is measured

What this does not answer yet

Empty catalog from a version mismatch (`VERSION_UNSUPPORTED`)

Practical checklist

Inventory sources

Get storefront readiness

Product discovery

Errors

AdCP versioning & negotiation

​Endpoint

​Request

​Parameters

​Response

​Errors

​Open the diagnostics surface

​Start with the inventory source

​Inspect recent AdCP activity

​Buyer discovery debug output

​Storefront candidates and source calls are different stages

​Empty responses and latency do not change future ranking

​How source latency is measured

​What this does not answer yet

​Empty catalog from a version mismatch (VERSION_UNSUPPORTED)

​Practical checklist

​Related

Inventory sources

Get storefront readiness

Product discovery

Errors

AdCP versioning & negotiation

Endpoint

Request

Parameters

Response

Errors

Open the diagnostics surface

Start with the inventory source

Inspect recent AdCP activity

Buyer discovery debug output

Storefront candidates and source calls are different stages

Empty responses and latency do not change future ranking

How source latency is measured

What this does not answer yet

Empty catalog from a version mismatch (`VERSION_UNSUPPORTED`)

Practical checklist

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