[Automated] Draft docs (kagent): feat: add token passthrough for remote MCP servers

docs-site/content/kagent/1.x/agents/agent-harness.md

@@ -303,6 +303,7 @@ The `kagent` harness accepts every AgentTemplate feature. Codex and Claude run a
 | A subagent binding cannot itself carry tools, skills, plugins, or nested agents, and must use the same provider and credentials as the agent that binds it. | `codex`, `claude` |
 | The agent sees every tool that an {{< gloss "MCP" >}}MCP{{< /gloss >}} server offers, because Claude does not support partial tool selection. A binding that names a subset of tools binds the whole server instead. The Agent still reconciles, and reports the decision in `status.warnings` as `Claude RemoteMCPServer "<name>" does not support partial tool selection`. | `claude` |
 | A RemoteMCPServer must use the `STREAMABLE_HTTP` protocol. `SSE` is rejected. | `codex` |
+| A RemoteMCPServer that sets `tokenPassthrough` is rejected. | `codex`, `claude` |
 | Structured output is rejected, with `Harness runtime "<name>" does not support structured output`. | `codex`, `claude`, `byo` |
 
 For more information about what an AgentTemplate can bind, see [About tools]({{< link path="skills-and-mcp/about-tools" >}}).

docs-site/content/kagent/1.x/skills-and-mcp/about-tools.md

@@ -39,7 +39,7 @@ tools:
 
 ### Tool selection on the Claude harness
 
-Claude's MCP configuration has no per-tool allowlist. On the Claude harness, the `tools` list does not narrow a server, and the agent reaches every tool that the server serves. kagent admits the {{< gloss "Revision" >}}revision{{< /gloss >}} either way. Unless the list exactly matches the tools that kagent currently discovers on the server, kagent also records a warning on the Agent.
+Claude's MCP configuration does not have a per-tool allowlist. On the Claude harness, the `tools` list does not narrow a server, and the agent reaches every tool that the server serves. kagent admits the {{< gloss "Revision" >}}revision{{< /gloss >}} either way. Unless the list exactly matches the tools that kagent currently discovers on the server, kagent also records a warning on the Agent.
 
 ```sh
 kubectl get agent <name> -n <namespace> -o jsonpath='{.status.warnings}'
@@ -49,6 +49,32 @@ To keep an agent on the Claude harness away from a tool, limit what the server e
 
 For the bundled tool server, see the installation-level settings that drop providers and write tools in [Tools ecosystem]({{< link path="reference/tools-ecosystem#narrow-what-kagent-tool-server-serves" >}}).
 
+### Caller token passthrough
+
+An MCP server that authorizes each user individually needs the caller's token. For the authorizing server, set `tokenPassthrough: true` on its RemoteMCPServer resource. The agent sends the bearer token from the incoming agent-to-agent (A2A) request to the server as its `Authorization` header. When the incoming request does not present a bearer token, the MCP request fails.
+
+```yaml
+apiVersion: api.kagent.dev/v1alpha3
+kind: RemoteMCPServer
+metadata:
+  name: user-mcp-server
+  namespace: kagent
+  labels:
+    kagent.dev/discovery: disabled
+spec:
+  description: An MCP server that authenticates each caller.
+  url: https://mcp.example.com/mcp
+  protocol: STREAMABLE_HTTP
+  tokenPassthrough: true
+```
+
+| Field | Description |
+| ----- | ----------- |
+| `kagent.dev/discovery` label | The controller does not have a caller token, so controller-side tool discovery against this server fails. Set the label to `disabled` to turn discovery off. For more information, see [Turn tool discovery off for a server]({{< link path="reference/tools-ecosystem#turn-tool-discovery-off-for-a-server" >}}). |
+| `tokenPassthrough` | Sends the caller's bearer token as `Authorization: Bearer <token>`. The RemoteMCPServer cannot also set an `Authorization` header in `headersFrom`. The `codex` and `claude` harnesses reject a RemoteMCPServer that sets this field. For more information, see [Tool and skill support]({{< link path="agents/agent-harness#tool-and-skill-support" >}}). |
+
+Every model and MCP server that an agent reaches at the server's origin must also forward the caller's token. Otherwise, the Agent reports the `Compatible` condition as `False`. For more information, see [Forward the caller's token]({{< link path="setup/model-providers/about-model-providers#forward-the-callers-token" >}}).
+
 ## Subagents as tools
 
 A `subAgent` binding points at another AgentTemplate in the same namespace so that one agent can route work to another agent. The model reads the `description` when it decides whether to route work here. A description that states plainly what the bound agent is for therefore matters more than the detail of its configuration.
@@ -70,7 +96,7 @@ Every field is required. For the complete schema, see the [API reference]({{< li
 | `subAgent.description` | The text that tells the parent agent when to route work here. |
 | `subAgent.templateRef.name` | The AgentTemplate to bind, in the same namespace. |
 
-kagent compiles the bound template into the parent agent's own configuration and runs it inside the parent's {{< gloss "Actor" >}}Actor{{< /gloss >}}, so the two agents share one sandbox. A bound template is not an MCP server and has no endpoint of its own. A bound template also does not need an {{< gloss "Agent" >}}Agent{{< /gloss >}} resource because the parent's Agent runs it.
+kagent compiles the bound template into the parent agent's own configuration and runs it inside the parent's {{< gloss "Actor" >}}Actor{{< /gloss >}}, so the two agents share one sandbox. A bound template is not an MCP server and does not have an endpoint of its own. A bound template also does not need an {{< gloss "Agent" >}}Agent{{< /gloss >}} resource because the parent's Agent runs it.
 
 > [!NOTE]
 > Dedicated subagents, which would give a bound agent its own Harness, Session, and Actor, are not part of the served API. The `subAgent.agentRef` field that would select one is unavailable, so `templateRef` is the only binding that you can write today.