Reference implementation Data compiled from public sources as of 2026-10-26. Not an assessment, certification or recommendation. Confirm current status with the vendor and the issuing body.
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Trace · registry probe · T1 reproducible run

Registry probe of LangChain Deep Agents's discovery endpoints

LangChain Deep Agents · 2026-10-11 · AgentDossier refresh · harness probe-1.0

Scenario. Fetch and validate the ARD manifest, A2A agent card and MCP server card at the publisher's well-known paths

Observed. A2A verified (unsigned); MCP invalid

EntryGET on the publisher's well-known discovery paths
Actionsserved Agent2Agent (A2A) document; served Model Context Protocol (MCP) document
Egressno
Human approval—
Secrets touchedno
Bundlebundles/tr_st_63dee3d46869a3ed_af504c83 · sha256:7dee2675ef05696ef51d5d4181ea05d78e09492ef8254dbda1fd333cf22840fb · download (JSON)
Chainsha256:e6e5eee7f25b3ab5769700b36bf154fdc4761c7b96ad60598f06162efcd904d7
prev sha256:2a407ccaa319071f0bf019ea57253339c4fddcb010bdc3a8ab9754e8a206f966

Transcript

# Probe transcript — LangChain Deep Agents

Agent `res_63dee3d46869a3ed` · publisher domain `docs.langchain.com` · 2026-10-11 · harness probe-1.0

## Agent2Agent (A2A)

- requested `https://docs.langchain.com/.well-known/agent-card.json`
- result: **verified**
- declared version: 0.3 (card 1.0.0)
- signed: no
- skills advertised: langchain

## Model Context Protocol (MCP)

- requested `https://docs.langchain.com/.well-known/mcp.json`
- result: **invalid**

---
Observation only: the registry fetched public well-known paths and validated the documents against the protocol specifications. No credentials, no message exchange beyond discovery, nothing written.

Produced automatically on every refresh; a new bundle is written only when the observation changes

A trace describes one version on one date. It is evidence of behaviour, never a certification. Dispute it through the agent's dossier; corrections are appended, never overwritten.