diff --git a/app/db/migrations/017_posts_campaign_nullable.sql b/app/db/migrations/017_posts_campaign_nullable.sql
new file mode 100644
index 0000000..1d569d7
--- /dev/null
+++ b/app/db/migrations/017_posts_campaign_nullable.sql
@@ -0,0 +1,28 @@
+-- Make campaign_id nullable on posts to support manual opportunity posts
+-- that don't belong to a campaign. SQLite requires a full table rebuild
+-- to drop a NOT NULL constraint.
+CREATE TABLE posts_new (
+    id              INTEGER PRIMARY KEY AUTOINCREMENT,
+    campaign_id     INTEGER REFERENCES campaigns(id),
+    variant_id      INTEGER REFERENCES campaign_variants(id),
+    opportunity_id  INTEGER REFERENCES opportunities(id) ON DELETE SET NULL,
+    platform        TEXT NOT NULL DEFAULT 'reddit',
+    target          TEXT NOT NULL,
+    status          TEXT NOT NULL DEFAULT 'pending',
+    url             TEXT,
+    error_msg       TEXT,
+    screenshot_path TEXT,
+    triggered_by    TEXT DEFAULT 'scheduler',
+    posted_at       TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+INSERT INTO posts_new SELECT id, campaign_id, variant_id, opportunity_id, platform, target, status, url, error_msg, screenshot_path, triggered_by, posted_at FROM posts;
+
+DROP TABLE posts;
+ALTER TABLE posts_new RENAME TO posts;
+
+CREATE INDEX IF NOT EXISTS idx_posts_campaign ON posts(campaign_id);
+CREATE INDEX IF NOT EXISTS idx_posts_opportunity ON posts(opportunity_id);
+CREATE INDEX IF NOT EXISTS idx_posts_target ON posts(target);
+CREATE INDEX IF NOT EXISTS idx_posts_status ON posts(status);
+CREATE INDEX IF NOT EXISTS idx_posts_posted_at ON posts(posted_at);