Dynamic update of presentation definitions

[cre8]

When I started my agent, I want to let the user update the presentation definition. It's possible to write this into the pex-store, but the SIOPv2PR instance is loading the values on start.

I tried to update them like this:

const siop = new SIOPv2RP({
    defaultOpts: {
      didOpts: {
        checkLinkedDomains: CheckLinkedDomain.IF_PRESENT,
        identifierOpts: {
          identifier,
          kid,
        },
      },
    },
    instanceOpts: [],
  });  
  setInterval(() => {
    const rep = agentConfig.datasource.getRepository(KeyValueStoreEntity);
    //TODO: this is not the preferred way since we need to reload the application to get the latest version.
    rep.find({ where: { key: Like('%oid4vp%') } }).then(
      (res) => {
        const instanceOpts = res.map((r) => {
          const content = JSON.parse(r.data).value as IPresentationDefinition;
          return {
            definitionId: content.id,
            definition: content,
          } as IPEXInstanceOptions;
        });
        //@ts-ignore
        siop.opts.instanceOpts = instanceOpts;
      },
      () => {}
    );
  }, 1500);

This works, until the first presentation request for this definition is made. Then the instance is getting saved in the internal map and will always interact with it. So updating the instanceOpts has no effect on this.

Is there another way to update the values without restarting an instance? A restart of the agent could reset an ongoing presentation flow so I want avoid this step.

[nklomp]

I want to know a bit more about your use case. Because updating a definition mid-flight whilst sessions are running sounds problematic to begin with.

What if certain OPs already have performed a request with the old definition. They will send in a submission based on the old definition. If you in the meantime changed the definition under their feet, it likely cause issues, because the new definition is different from the old one.

[nklomp]

What probably would be a better approach, and which we will need to look into soon anyway, is to implement new session support with persistence, where we also would store a reference to a full definition. Then you could apply versioning to definitions and then thus also support sessions against multiple versions of the same definition id.

[cre8]

I have implemented a multi agent system where a backend is spinning up multiple agent instances that can be managed by different users. Users are able to create update and delete credential templates (to issue credentials) and to define presentations requests via a web application. Each agent can be reached via `exmaple.com/ and is publishing the endpoints to interact with it.

So compared to e.g. your demo application (which is fine for specific use cases) the values can change over time. But restarting the whole agent in the background can lead to some other side effects like you mentioned