> ## Documentation Index > Fetch the complete documentation index at: https://docs.superx.so/llms.txt > Use this file to discover all available pages before exploring further. # Add a signal to an agent > Add one thing for the agent to watch: a search (`keyword_watch`), an account's posts (`profile_watch`), the people an account follows (`follower_watch`), or the members of a public X list (`list_watch`). New leads start arriving over the following minutes and days; nothing is returned synchronously. One target per call: each add resolves its target live or compiles the search, so there is no batch form. Each plan caps how many signals one agent may hold (403 `cap_reached`) and an agent may watch each target once (409 `duplicate_signal`). `profile_watch`, `follower_watch` and `list_watch` consume one unit of the enrichment allowance; `keyword_watch` consumes none. Only PUBLIC X lists can be watched. No `Idempotency-Key`: the duplicate rule already makes a repeat harmless. Works for your main account or any account linked to it (`account_id`); accounts shared with you are read-only. ## OpenAPI ````yaml /api-reference/openapi.yaml post /v1/signals/agents/{id}/signals openapi: 3.1.0 info: title: SuperX API version: 1.0.0 description: > The SuperX public API: your Twitter/X content, analytics, audience and scheduling data over REST. All endpoints require an API key (`Authorization: Bearer sxk_...`) except `GET /v1/docs`. Keys are created in the SuperX app under Account > API / MCP / CLI and are server-side secrets. Timestamps are UTC ISO-8601 in both directions; inputs must carry an explicit `Z` or numeric offset. Every authenticated response carries `X-RateLimit-Limit`, `X-RateLimit-Remaining` and `X-RateLimit-Reset` headers. contact: name: SuperX url: https://superx.so servers: - url: https://api.superx.so security: - apiKey: [] tags: - name: Identity - name: Content - name: Analytics - name: Inspiration - name: Audience - name: Contact Lists - name: Signals - name: Datasets description: | The audience collections Ask SuperX builds in the app: the repliers, quoters or reposters of a post, the members of an X list, your own posts or replies, or a research brief. Collect a new one with `POST /v1/datasets` (a big collection answers 202 and finishes in the background), read it, export it, or copy the people in it into a contact list you created. Datasets are kept for 30 days, and the ones Ask SuperX builds in the app show up here too. - name: Engage description: | The account's saved Engage feeds and the candidate posts in them, for an agent to score and a person to act on. Read-only by design. These endpoints return feed candidates for a person to review; replies are written and sent by a person in the SuperX app, which is why there is no reply endpoint here. Sending spammy, automated, or AI-generated replies that read as inauthentic may get your X account suspended under X's inauthentic-behavior rules and your SuperX account terminated. AI suggestions must be reviewed and meaningfully edited before they are sent, and you are solely responsible for what you post. Reply activity is logged and may be audited. - name: X Lookups description: | Read any public post, its top replies, any public profile, or an account's latest posts LIVE from X, rather than from SuperX's stored data. These are owner-scoped, so none of them take an `account_id`: nothing about a public lookup is per-X-account. They cost the tighter live-enrichment allowance and share a daily allowance of 300 live lookups with Ask SuperX inside the app, so use them for what you actually need rather than to sweep. Repeat lookups within 15 minutes may be served from a short-lived server-side cache. - name: Tools description: | The composer helpers from the SuperX app, over the API: rewrite a post, edit one selected piece of it, apply one preset rewrite, check a claim, or compare two versions. Every one of them returns TEXT and writes nothing. Nothing here is posted, scheduled or sent; save what you keep with `POST /v1/posts/draft` or `POST /v1/scheduled-posts`. They cost AI credits, measured from the models' real cost, and spend no live-data allowance. - name: Media - name: Workers description: | The posts the account's Workers have written, and the three things a person does with one: save it as a draft, schedule it, or dismiss it. A Worker is a scheduled AI writer set up in the SuperX app. Creating, editing and running one stays in the app, so there is no create or run endpoint here. What a run produces lands in the app's "To review" queue and is read with `GET /v1/workers/suggestions`. NOTHING HERE POSTS TO X. Drafting or scheduling a suggestion writes a post the user can see in the app and on `GET /v1/scheduled-posts`, exactly like the app's own buttons. AI output must be reviewed and meaningfully edited by a person before it goes out, so show the text to the user and confirm the time before you schedule anything. - name: Scheduling - name: Tags - name: Context - name: Queue - name: DMs description: | Queue direct messages into the account's own DM pipeline, and read or cancel what is waiting. NOTHING HERE SENDS A MESSAGE. `POST /v1/dm/campaigns` enqueues; the SuperX app's scheduler is what sends, within the account's daily and monthly DM limits, so the create response is counts, not deliveries. Unsent messages can be cancelled until the scheduler picks them up. You are responsible for the messages you queue. Unsolicited or automated bulk DMs may get an X account suspended under X's rules and a SuperX account terminated, so confirm the recipient list and the exact wording with the person on whose behalf you are queueing. - name: Articles - name: Meta paths: /v1/signals/agents/{id}/signals: post: tags: - Signals summary: Add a signal to an agent description: | Add one thing for the agent to watch: a search (`keyword_watch`), an account's posts (`profile_watch`), the people an account follows (`follower_watch`), or the members of a public X list (`list_watch`). New leads start arriving over the following minutes and days; nothing is returned synchronously. One target per call: each add resolves its target live or compiles the search, so there is no batch form. Each plan caps how many signals one agent may hold (403 `cap_reached`) and an agent may watch each target once (409 `duplicate_signal`). `profile_watch`, `follower_watch` and `list_watch` consume one unit of the enrichment allowance; `keyword_watch` consumes none. Only PUBLIC X lists can be watched. No `Idempotency-Key`: the duplicate rule already makes a repeat harmless. Works for your main account or any account linked to it (`account_id`); accounts shared with you are read-only. operationId: addSignalAgentSignal parameters: - name: id in: path required: true description: The signal agent's numeric id (from `GET /v1/signals/agents`). schema: type: integer requestBody: required: true content: application/json: schema: allOf: - $ref: '#/components/schemas/SignalInput' - type: object properties: account_id: type: string description: >- Any account you own, meaning your main account (the default when omitted) or one linked to it. An account shared with you returns `403 writes_main_account_only`. example: type: follower_watch handle: naval responses: '201': description: The created signal. headers: X-RateLimit-Limit: $ref: '#/components/headers/X-RateLimit-Limit' X-RateLimit-Remaining: $ref: '#/components/headers/X-RateLimit-Remaining' X-RateLimit-Reset: $ref: '#/components/headers/X-RateLimit-Reset' content: application/json: schema: type: object properties: data: $ref: '#/components/schemas/SignalAgentSignal' example: data: id: 118 type: follower_watch handle: naval name: Naval avatar: https://pbs.twimg.com/profile_images/... query: null list_name: null status: active status_detail: null last_run_at: null created_at: '2026-09-07T10:00:00.000Z' '400': $ref: '#/components/responses/InvalidParameter' '401': $ref: '#/components/responses/Unauthorized' '403': description: >- Read-only key (`insufficient_scope`), an account shared with you (`writes_main_account_only`), a lapsed subscription, or the agent's per-plan signal limit is reached (`cap_reached`). content: application/json: schema: oneOf: - $ref: '#/components/schemas/ErrorEnvelope' - $ref: '#/components/schemas/LegacyErrorEnvelope' example: error: code: cap_reached message: >- This agent has reached its limit of 3 signals on the pro plan. Remove a signal in SuperX or upgrade your plan. '404': $ref: '#/components/responses/SignalTargetNotFound' '409': $ref: '#/components/responses/DuplicateSignal' '429': $ref: '#/components/responses/RateLimited' '502': $ref: '#/components/responses/UpstreamError' '503': $ref: '#/components/responses/UpstreamUnavailable' components: schemas: SignalInput: type: object required: - type description: >- One thing for a signal agent to watch. The target field depends on `type`: `query` for keyword_watch, `handle` for profile_watch and follower_watch, `list` for list_watch. properties: type: type: string enum: - keyword_watch - profile_watch - follower_watch - list_watch query: type: string maxLength: 180 description: >- keyword_watch only. A plain-language description of what the target customer posts about, or an X search. Operators pass through; engagement filters such as min_faves are rejected. handle: type: string maxLength: 15 description: >- profile_watch and follower_watch only. An X username, with or without a leading @. list: type: string description: >- list_watch only. A public X list id, or a link like https://x.com/i/lists/1234567890. SignalAgentSignal: type: object description: >- One watched signal on an agent. Which fields are set depends on the type (handle/name/avatar for profile and follower watches, query for keyword watches, list_name for list watches). properties: id: type: integer type: type: string enum: - profile_watch - follower_watch - keyword_watch - list_watch handle: type: string nullable: true name: type: string nullable: true avatar: type: string nullable: true query: type: string nullable: true list_name: type: string nullable: true status: type: string status_detail: type: string nullable: true last_run_at: type: string format: date-time nullable: true created_at: type: string format: date-time nullable: true ErrorEnvelope: type: object required: - error properties: error: type: object required: - code - message properties: code: type: string description: Stable machine-readable error code. message: type: string retry_after: type: integer description: Seconds to wait before retrying (rate-limit errors only). LegacyErrorEnvelope: type: object required: - error description: | Legacy shape used ONLY by the shared subscription middleware: a plain string `error` field. Seen on `403` when the subscription has lapsed (string starts with "subscription_required:") and on `500` when subscription verification fails (string starts with "internal_error:"). properties: error: type: string example: >- subscription_required: The SuperX API requires an active subscription headers: X-RateLimit-Limit: description: The limit of the rate window closest to exhaustion. schema: type: integer X-RateLimit-Remaining: description: Requests remaining in that window. schema: type: integer X-RateLimit-Reset: description: Unix timestamp (seconds) when that window resets. schema: type: integer responses: InvalidParameter: description: A parameter is missing, malformed, or out of range. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: invalid_parameter message: since must be a UTC ISO-8601 timestamp Unauthorized: description: >- Missing/malformed Authorization header (`unauthorized`) or an unknown/revoked key (`invalid_api_key`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: invalid_api_key message: Unknown or revoked API key SignalTargetNotFound: description: >- The agent id is not one of your signal agents (`agent_not_found`), the handle did not match an X account (`user_not_found`), or the X list is private or unavailable (`x_list_not_found`). content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: user_not_found message: No X account matches that handle. DuplicateSignal: description: >- The agent already watches that target. An agent may hold each target once. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: duplicate_signal message: >- This agent already watches that target. List the agent's signals at /v1/signals/agents. RateLimited: description: Rate limit exceeded (limits vary by plan). Honor Retry-After. headers: Retry-After: description: Seconds to wait before retrying. schema: type: integer X-RateLimit-Limit: $ref: '#/components/headers/X-RateLimit-Limit' X-RateLimit-Remaining: $ref: '#/components/headers/X-RateLimit-Remaining' X-RateLimit-Reset: $ref: '#/components/headers/X-RateLimit-Reset' content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: rate_limited message: >- Rate limit exceeded for the Pro plan (30 requests/min). Upgrade for higher limits. retry_after: 42 UpstreamError: description: A dependent SuperX service returned an unexpected response. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: upstream_error message: Failed to fetch scheduled posts. Try again shortly. UpstreamUnavailable: description: >- The scheduling service is temporarily unreachable. Safe to retry; reuse your Idempotency-Key on POST. content: application/json: schema: $ref: '#/components/schemas/ErrorEnvelope' example: error: code: upstream_unavailable message: >- The scheduling service is temporarily unavailable. Retry with the same Idempotency-Key. securitySchemes: apiKey: type: http scheme: bearer description: >- A SuperX API key ("sxk_..."), created in the SuperX app under Account > API / MCP / CLI. Keys are server-side secrets. ````