Discover and govern A2A/multi-agent registries
Need a registry to publish/find Agent Cards (A2A) and related MCP/skills across teams or the public internet — not just an MCP directory.
At a glance — Oct 2026
Updated 2026-10-27 · forward this page: /jtbds/a2a-agent-discovery#briefScores as of 2026-09-14 (43 days old; Depot marks scores stale after 30 days). The pick is still Depot's current editorial pick; it has not been re-reviewed since. Prices below carry their own dates.
- Depot Pick
- AWS Agent Registry · 7.96/10 for this job (curated estimate, high confidence)
Prefer governed enterprise catalogs when IAM/approvals matter; open registries when protocol interop and zero lock-in matter. Distinct from mcp-discovery.
- Runner-up
- Google Cloud Agent Registry · 7.78/10
Scores higher than the pick on: Maturity / track record.
- When not to use the pick
- Not on AWS — Google Agent Registry if GCP; public/OSS multi-vendor — OpenAgora or a2a-registry.dev; MCP-only directories — Smithery/Glama/PulseMCP/official registry.
- Lock-in / migration
- The pick has lower stored lock-in risk than runner-up Google Cloud Agent Registry (7 vs 7.2). Self-host fallback listed for this job: A2A protocol.
- Sourced price (no comparable unit)
Pick: no sourced price in this job's unit (no_sourced_price).
No cheapest SKU (no_comparable_unit_for_job). No price was invented.
- Free option
- No free resource lists this job. A cheap paid SKU is not a free option.
- Failure modes to watch
- Hallucinated tool arguments: Reject a call that fails the current schema or names an unknown id, and do that before the tool runs a side effect.
- Identity confusion: Bind every tool call to a user or tenant id. Refuse the call if that id changed mid-task. For a public bot, the operator owns the words the bot shows.
- Instruction drift: Restate the stop condition in the trace. End the run when it is met. Review long traces for steps that do not serve the original task.
- Inter-agent misalignment: Log the assigned subtask next to the worker's stated result. The lead rejects a result that does not match the assignment.
- Observability gap: Alert on a drop in trace ingestion and on certificate expiry for the trace host. Do not treat a missing trace as a successful quiet run.
- Partial tool success: Require a per-item status and a failure count. Success for the task requires the failed count to be zero or explicitly handed to a retry queue.
Cite: Agent Provider Depot, Depot Pick for a2a-agent-discovery: aws-agent-registry, scores as of 2026-09-14. Agents: GET /api/decide?jtbd=a2a-agent-discovery
Free Discover and govern A2A/multi-agent registries options · for orchestrator agents
AWS Agent Registry
Prefer governed enterprise catalogs when IAM/approvals matter; open registries when protocol interop and zero lock-in matter. Distinct from mcp-discovery.
Pricing (directional): As of 2026-09-14 (aws.amazon.com/bedrock/agentcore/pricing): AWS Agent Registry — first 5k records/mo free, then $0.40/1k records; Search API first 1M free then $0.020/1k; List+Get first 2M free then $0.004/1k. Catalogs MCP servers, A2A age…
Lock-in risk: higher = more lock-in (worse). Overall already inverts this dimension.
Depot pick for enterprise A2A/MCP discovery when the fleet already lives on AWS. OpenAgora/a2a-registry.dev for public/OSS discovery; PulseMCP/Smithery for MCP-only directories.
Quote for Discover and govern A2A/multi-agent registries
Depot Pick stays AWS Agent Registry. Prices below are sourced SKU rows only (as of 2026-10-27). Input and output are not blended. GET /api/quote?jtbd=a2a-agent-discovery
Nothing was compared. no comparable sourced unit for this job; chat input $/1M and other units were not borrowed pickIsPriceWinner is null.
Sourced price unavailable for the Depot Pick. No row in the pricing index.
5 of 5 candidates have no sourced price row. 5 are excluded from the Matching price comparison (none). no comparable sourced unit for this job; chat input $/1M and other units were not borrowed
Runners-up
Google Cloud Agent Registry
GCP twin of AWS Agent Registry. Use when agents already sit on Vertex/Gemini Enterprise; otherwise prefer…
OpenAgora
Best open A2A discovery default for multi-vendor agents. AgentVerse if you are already Fetch.ai/uAgents…
A2A Registry (a2a-registry.dev)
Lightweight public/self-host A2A discovery. Prefer OpenAgora if you want LF-aligned A2A v1.0 + live testing…
PulseMCP
MCP directory peer to Glama/Smithery — best when you need a curated sub-registry for a platform, not…
When NOT to use the top pick
Not on AWS — Google Agent Registry if GCP; public/OSS multi-vendor — OpenAgora or a2a-registry.dev; MCP-only directories — Smithery/Glama/PulseMCP/official registry.
Full ranking (score table)
Ranked with this JTBD's weights. Scores are curated estimates unless marked otherwise. Agents: prefer /api/decide then this table for tie-breaks.
| # | Provider | Overall | Fit | $/perf | Latency | DX | As of |
|---|---|---|---|---|---|---|---|
| 1 | AWS Agent RegistryDepot Pick | 8.0 | 8.6 | 8.0 | 8.8 | 7.8 | 2026-09-14 |
| 2 | OpenAgora | 7.9 | 8.2 | 9.2 | 7.2 | 8.4 | 2026-09-14 |
| 3 | Google Cloud Agent Registry | 7.8 | 8.5 | 7.2 | 8.8 | 7.6 | 2026-09-14 |
| 4 | PulseMCP | 7.7 | 8.4 | 7.0 | 7.8 | 8.2 | 2026-09-14 |
| 5 | A2A Registry (a2a-registry.dev) | 7.6 | 7.8 | 9.0 | 7.0 | 8.0 | 2026-09-14 |
Score methodology for this job
Prefer governed enterprise catalogs when IAM/approvals matter; open registries when protocol interop and zero lock-in matter. Distinct from mcp-discovery.
capabilityFit: 25%pricePerformance: 18%latencyReliability: 15%developerDx: 15%privacyPosture: 10%lockInRisk: 7%maturity: 10%